20 ms·

Study: people who eat and exercise the same as people 20 years ago are fatter

140 points by fisherjeff 11y ago

hughw 11y ago
Well sure, but we're twenty years older, too.
- hughw 11y ago
  No joking on HN!
personjerry 11y ago
Weight gain is simple: calorie intake - calorie expenditure. The amount of calories in our food tends to go up over 20 years. Doing the same activities consumes the same amount of calories after 20 years. Thus we would have more caloric surplus, and likely gain more weight than people 20 years ago with less caloric food. Pretty simple imo.
- zacwest 11y ago
  From the article you're writing a comment to: > A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher.
  - toomuchtodo 11y ago
    Its strange really. I'm on a ketogenic diet, and hear people preach the caloric balance constantly, that it doesn't matter what my macros are as long as I consume less calories than I burn daily. Yet, I consume close to my previous garbage diet calories and I lose about 2-3lbs/week due to my high fat/moderate protein/very low carb (<15g/day of carbs) diet. Go figure, it appears that caloric energy balance isn't the only factor.
    - jfoutz 11y ago
      It's an absolute limit. Perhaps there are specific modes that are a a few percent more or less efficient. Nonetheless, you eat less than you burn, you lose weight.
      - im3w1l 11y ago
        Him burning it is not the only possibility. Maybe he is shitting it out? Maybe bacteria in his body are burning it for him?
        toomuchtodo 11y ago
        Gut flora is a big possibility as to the discrepancy. I imagine there are some gut flora that are more adapt at breaking down carbohydrates than others, saturating the body in unnecessary energy to absorb.
    - com2kid 11y ago
      From someone who's been doing keto for several years now. A: Pre-Keto, odds are you we underestimating how many calories you were eating. Unless you were tracking every single thing you ate, there is a high probability you just didn't realize how many calories you were consuming. B: It is super hard to over eat on Keto. It is possible, take lots of liquid calories in (heavy cream can do this easily!), and there are some other real screw ups, but eating 3000 calories of steak is pretty damn hard. C: What you are reporting is common for people who have a lot of weight to lose. At some point it becomes a lot harder, at first you just have to sort of watch things, then you eventually do have to count calories. (Especially if you want a six pack, holy crap do you have to count calories!)
      - toomuchtodo 11y ago
        Thanks for that info! Did you ever experience symptoms similar to eye fatigue? I think I might be not consuming enough sodium and/or potassium; I'm going to up my doses of both to test my theory.
  - tdylan 11y ago
    They didn't control the energy expenditure to any meaningful degree. Essentially worthless.
    - _delirium 11y ago
      The point of the study, from what I can tell, was to show that calories+macronutrients+exercise, the three main current targets of anti-obesity intervention, fail to account for a large portion of observed population-scale changes. They aren't arguing generally against total energy balance being involved, only that those three quantities don't constitute a sufficient measure of total energy balance. The implication would be that there are likely other sources of variation, e.g. changes in digestion, metabolism, etc. (the study doesn't really go out on a limb and speculate on that part).
  - tomp 11y ago
    That doesn't mean much... Maybe people who eat the same now ate more in the past, which is why they're still fatter.
- hspak 11y ago
  I'd recommend reading Good Calories, Bad Calories by Gary Taubes. He explains how this is not really the case. It was written back in 2007; I'm sure there's more research out there to prove this point.
  - tdylan 11y ago
    From what I've seen Garrys hypothesis was proven wrong by Alan Aragon.
    - billjings 11y ago
      Taubes' end-of-the-book hypothesis about Atkins diets and the like isn't that great, but the whole initial portion of the book trashing the fat hypothesis is great. If you enjoy scientific writing, I promise that you will get a lot out of it, whether you agree with him or not. He's a fantastic writer, and an exhaustive researcher.
- bemmu 11y ago
  While that's also certainly true, the article says that in this case the calorie intake was the same. They were guessing gut bacteria could be different. Maybe the formula is calories in * bacteria efficiency - calories out?
- Guzba 11y ago
  A person gains weight because they intake more calories than they expend. Certainly. A room gets more crowded when more people enter than exit. Obviously true. Neither of these statements tell you why that is happening though, and that is important thing. So, why are people eating more calories? Or, since the articles says they aren't, could the sources of calories matter? (They do.)
  - theophrastus 11y ago
    This simple thermodynamic model intake minus expenditure leaves out (at least) one dynamic metabolic feature: this engine can change its tendency for storage (weight gain) in a single organism or in a community of organisms given time. A change in the community storage tendency is what is alluded to in the linked article. That is, the organism can allow the excess calories to pass on by, or it can store it as fat (or glycogen). This, for instance, is the holy grail of weigh managing pharmaceuticals: to discover those effectors of "now store every un-expended calorie (as fat)". So finally it's something like: intake - expenditure = available for storage, but might not be stored.
    - DennisP 11y ago
      And the other variable is how well the body turns fat reserves back into available energy. If that mechanism is inefficient then the equilibrium will be higher body fat. People seem to have an idea that every human body can just instantly burn however much fat it needs to burn to meet demand. It seems more likely that there's a limit to how fast the body can burn fat, which for some people is unusually low, and that if there's not enough energy available you'll be forced by thermodynamics to move less, think poorly, and produce less body heat.
- com2kid 11y ago
  There is a type of seaweed that if your average American eats it, there are zero calories absorbed. If most Japanese citizens eat it, they will absorb calories from it. There is a gut bacteria common in the Japanese population that extracts calories from this type of seaweed. "calories in" is that calories that went down your throat. It is calories that your body was able to digest, and "your body" includes many types of bacteria that are unique to each person and also unique to different population groups (meaning that some populations share commonalities in gut flora). It is possible that certain antibiotics have wipe out some types of gut flora, allowing others to proliferate more. That alone could increase calorie absorption. (Or cause a host of other problems!) It is possible that having a diet too heavily reliant upon one type of food results in an imbalance of some type. The problem is, this is a brand new area of research and we just don't know yet. But it is sure as heck known that it is more complicated than "calories in food down the throat".
  - tdylan 11y ago
    Link to data/research?
    - com2kid 11y ago
      http://www.npr.org/templates/story/story.php?storyId=125675700 http://www.npr.org/templates/story/story.php?storyId=1256757... Actual suspected caloric difference is minimal, after all, well, it is seaweed, not a very dense food stuff. :) I'm not going to link to antibiotics causing gut flora problems, it is well known and responsible doctors actually can prescribe a nice little compact pill full of gut bacteria that replaces the ones wiped out as a side effect of antibiotics. The stuff about a biased diet messing up gut bacteria is also hard to find research on (I've read it, but it is a PITA to find again). Basically different bacteria specialize in breaking down different types of food. If you have a diet lacking in some major food group, that stock of bacteria runs low. Vegans can have this issue if they go back to eating meat. There is typically some tiny supply of the needed bacteria left and the population is restored after awhile, but the initial few hamburgers can be somewhat uncomfortable.
      - 11y ago
- billjings 11y ago
  Right, but physiology, psychology, and even sociology can all influence both calorie intake and expenditure. Send a kid to football camp, and they'll eat more and spend more calories. So: hard problem. Not strictly a technical problem, either.
- stevebmark 11y ago
  You think it's "pretty simple" because you haven't done any in depth research on the subject. Telling people to eat less and move more to lose weight is a recipe for failure. You have no qualifications but keep repeating the calories in calories out mantra. Until you've told this to hundreds of your patients and watching hundreds of them fail despite your useless advice, stop trying to shove your foot into the nutritional science door.
  - nightski 11y ago
    While I respect the knowledge of doctors, often the "wisdom" they have does not agree with one another. We need a better approach than gut feeling. I highly doubt simply telling a mantra like calories in vs. calories out to patients is going to change their behavior much (does the doctor spend months in the home of a patient helping them follow their advice?). It's not a very scientific way to go about it.
- PhasmaFelis 11y ago
  > The amount of calories in our food tends to go up over 20 years. RTFA, please. Paragraph five, specifically.
- deleted 11y ago
  [deleted]
im3w1l 11y ago
I do not have access to the fulltext but from the abstract, it seems they may only have included structured leisure time physical activity like playing football one hour every Monday (what could "Physical activity frequency data ... in 14,419 adults between 1988 and 2006" plausably include?) I would think there is less unstructured physical activity nowadays. Both at home and at work.
deleted 11y ago
[deleted]
xiaoma 11y ago
> A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher. I think the recent obsession with macronutrients is a big part of the problem. I'm not sure if the macronutrient ratio I eat has changed much from when I was growing up with my grandmother's cooking, with the exception of three failed experiments with low carb diets and a couple of other small experiments. The thing is that in the 80s, as a kid, I was more likely to be eating traditional American staples, like corn flakes or oatmeal and a banana for breakfast, and a typical meal would include meat, potatoes and a green vegetable. I drank some soda, but also about a quart of milk a day. Now I tend to eat out 9 times a week instead of 2 and I eat a lot more processed food unless I make a concerted effort not to. I avoid soda for the most part, but on the whole there's a lot more stuff in my diet that my great-grandparents wouldn't have recognized as food. I don't remember the last time I drank milk. Surely eating home baked bread or a piece of fruit isn't the same as eating a snack bar, eating meat isn't the same as drinking muscle milk, and fatty fish doesn't equate to pork rinds, etc. Macronutrient ratios just don't tell the whole story or even most of it.
- com2kid 11y ago
  I agree, the macros look sort of the same, but the source of those calories is much different. Just the types of cooking oil we use has changed a lot. Look at what goes into cookies now. It used to be butter, now I've seen recipes with canola oil. (if anyone tells you to use canola oil in your baked goods, ignore them and use butter!) There is evidence that gut bacteria is passed down from generation to generation, we could very well be seeing a delayed effect from public policy and health decisions made around the time the previous generation was growing up. oops. I am sort of on the fence about processed foods. A lot of canned food was eaten previously, fresh vegetables were not available year round, but a lot of the canning was done at home in glass jars. I am not one to be paranoid, but now all our canned food comes in coated aluminum cans. We have a few decades of aluminum cans being coated on the inside with BPA. It is know known that BPA can have harmful effects that take a long time to manifest. The point is, there are a lot of potential culprits, and it is going to take a long time to figure out what state unbridled capitalism has left public health in.
DiabloD3 11y ago
I don't have access to the study, but I suspect it doesn't say what The Atlantic is saying it's saying. I lost weight: I went from 340 pounds to 214 pounds in exactly a year, and then bottomed out at 184 eventually (I've been purposely trying to gain muscle lately, which has been causing my weight to meander in the 190s since then). My caloric intake hasn't changed in a way that can explain such a weight loss. I went from eating 1500-2000 calories a day to 1500-2000 calories a day (as in, no useful change, nothing that can explain 126 pounds in a year, disproportionately more of it towards the start than the end). Now, what I did change was drop all grains (grains, cereals, pastas, soy, rice), drop refined sugars (I still use coconut and true raw cane sugars (Muscovado, Barbados, or Turbinado) or straight up raw honey; all very sparingly, and corn syrup is banned in my house), dropped seed oils (no more "vegetable", soy, corn, or canola oils; replaced with coconut and olive oil, or leftover bacon fat when I have it), and legumes (I'm allergic to peanuts, and don't care for beans, so the only thing I lost there is peas; soy is a legume, but I include it in with grains due to how it is typically treated culinarily, and thus already banned in my house). So, given my experience, people are fatter because of reasons that cannot be explained by calories, such as chemicals in the things I quit eating causing unusual weight gain and halting the natural process of us burning endogenous fat. And it isn't like I'm the only person who did this, it is estimated over a million people have tried Paleo or some variant thereof and have significantly lost weight if they were overweight as long as they stuck with the lifestyle. Side note: I went from 340 to 214 with chronically under-exercising. I still chronically under-exercise to a point, even though I now lift weights and try to go on daily walks. I still don't get the high other people seem to get from exercising. So, you can't use "increased caloric burn" as why I lost so much weight, it just wasn't there.
- johnthedebs 11y ago
  How carefully were you tracking calorie intake? It's notoriously difficult and I simply don't believe you ate 1500-2000 calories at 340lbs and didn't lose weight (not that you need to convince me). In any case, congrats on the achievement!
  - DiabloD3 11y ago
abrons 11y ago
The article mentions prescription drugs but doesn't mention a widely used over the counter one: nicotine. US smoking rates are down about 50% over the last 20 years. (That's overall, I couldn't find any details by cohort.)
- jl6 11y ago
  Is the suggestion that people are channelling addictive behaviors from smoking to eating?
  - damian2000 11y ago
    Smoking reduces your appetite, leading to less eating and less weight. http://www.npr.org/2011/06/09/137085989/the-skinny-on-smoking-why-nicotine-curbs-appetite http://www.npr.org/2011/06/09/137085989/the-skinny-on-smokin...
    - jacobolus 11y ago
      Nicotine (without smoking) also has that effect, even in low doses. Actually there are two parts: it reduces appetite, and also raises the resting metabolic rate, cf. e.g. http://www.ncbi.nlm.nih.gov/pubmed/2773833 http://www.ncbi.nlm.nih.gov/pubmed/2773833
  - deleted 11y ago
    [deleted]
- desdiv 11y ago
  Good thinking, but the researchers already adjusted for smoking status [0][1]. [0] http://i.imgur.com/mQZ1ST9.png http://i.imgur.com/mQZ1ST9.png [1] http://i.imgur.com/Hi1x4Ab.png http://i.imgur.com/Hi1x4Ab.png
ejcx 11y ago
Health studies, especially when reported by some article in som publication without an original source are a mess. I personally am extremely skeptical of what the Atlantis says the findings of the paper are. I lost 50 lbs while eating a box of pop tarts per day while counting macros. It's anecdotal but that's the basis for my beliefs, and a lot of science supports it. One issue with health studies is how data is collected. Numerous studies have shown that a huge number of people are incapable of accurately tracking the number of calories they consume per day, and consistently under report their numbers. I believe it, it's hard in today's eat out culture. So...how sure are we that people were consuming the same number of calories? This is just one issue. There are tons more. If you happen to be in this thread and you are looking for health advice, my recommendation is to head to /r/fitness and read the FAQ.
NVI 11y ago
The original article is behind a paywall: http://www.obesityresearchclinicalpractice.com/article/S1871-403X(15)00121-0/abstract http://www.obesityresearchclinicalpractice.com/article/S1871.... Summary: Background To determine whether the relationship between caloric intake, macronutrient intake, and physical activity with obesity has changed over time. Methods Dietary data from 36,377 U.S. adults from the National Health and Nutrition Survey (NHANES) between 1971 and 2008 was used. Physical activity frequency data was only available in 14,419 adults between 1988 and 2006. Generalised linear models were used to examine if the association between total caloric intake, percent dietary macronutrient intake and physical activity with body mass index (BMI) was different over time. Results Between 1971 and 2008, BMI, total caloric intake and carbohydrate intake increased 10–14%, and fat and protein intake decreased 5–9%. Between 1988 and 2006, frequency of leisure time physical activity increased 47–120%. However, for a given amount of caloric intake, macronutrient intake or leisure time physical activity, the predicted BMI was up to 2.3 kg/m2 higher in 2006 that in 1988 in the mutually adjusted model (P < 0.05). Conclusions Factors other than diet and physical activity may be contributing to the increase in BMI over time. Further research is necessary to identify these factors and to determine the mechanisms through which they affect body weight.
agravier 11y ago
It's due to sugar in the vast majority of cases. Some starting point: https://www.youtube.com/watch?v=dBnniua6-oM https://www.youtube.com/watch?v=dBnniua6-oM
- agravier 11y ago
  I'd like some explanations for the downvotes. What I wrote is documented and I provide a link to a good source of explanations.
  - citeguised 11y ago
    The explanation is that facts don't matter for some people.
pazimzadeh 11y ago
I hope that they controlled for factors like smoking cigarettes.
- raverbashing 11y ago
  This might be a significant factor indeed (including passive smoking)
- desdiv 11y ago
  They have [0][1]. [0] http://i.imgur.com/mQZ1ST9.png http://i.imgur.com/mQZ1ST9.png [1] http://i.imgur.com/Hi1x4Ab.png http://i.imgur.com/Hi1x4Ab.png
mutagen 11y ago
Humans aren't the only ones gaining weight, animals are too: Fluffy article: http://news.discovery.com/animals/fat-pets-obesity-weight.htm http://news.discovery.com/animals/fat-pets-obesity-weight.ht... Nature article: http://www.nature.com/news/2010/101124/full/news.2010.628.html http://www.nature.com/news/2010/101124/full/news.2010.628.ht... Paper focusing on both lab animals (where diet is strictly controlled), pets, and feral rats living among humans: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081766/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081766/
hoodoof 11y ago
The air is fatter in the 21st century.
cwp 11y ago
I've noticed the same thing geographically. Twice now, I've taken a "sabbatical" and moved to Quito, Ecuador for a year to be near family. Both times, I lost weight when I arrived, stabilized at a leaner equilibrium, then gained the weight back when I returned to North America. Could be nutritional, could be bacterial, could social. Whatever it is, the effect is dramatic.
- hajrice 11y ago
  Noticed the same exact thing when I go to Europe, vs. America I think the article mostly applies to America. American food is just fattening
  - danlindley 11y ago
    The study factored in the nutritional value of the food, so your comment seems counter to their findings. "...eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher."
    - tnorthcutt 11y ago
      The study factored in the nutritional value of the food The study factored in the macronutrients, but that's not all that matters when it comes to food.
    - emp_zealoth 11y ago
      Except the calories are obsolete (meaningless) A lot of the food now is higly processed, ground to microns, resulting in way higher "usable engergy" that can be extracted. Especially the "cheap" food - full of awful sugars, stabilised fats or other junk, gelatine, mechanically abused.
      - pflanze 11y ago
        Your answer may look unscientific (hand-wavy, with the word "meaningless" being too strong, that's how I explain the downvotes), but I guess if eating is (partially) feeding gut bacteria, then the micro structure of the food could well matter a lot with regards of which kinds of bacteria it promotes and which it weakens, and hence change the composition of the biome.
vph 11y ago
You can't eat the same foods people ate 20 years ago. The cows aren't the same. The chickens aren't same. Cows and chickens today are more obese and eat more antibiotics than they used to be.
- elktea 11y ago
  It's due to what we feed them, as well. We even feed corn to farmed Salmon, which makes their Omega 3&6 ratios the opposite of what they naturally are.
ocharles 11y ago
Does this study factor in the huge life style changes over 20 years? Far more access to cars, and far more spending entire days sitting down (computer jobs, Netflix binge watching, etc). A lot of how we live has changed in 20 years, I'm inclined to think the problem lies there, not in environmental factors.
- weego 11y ago
  We had cars and tv/video games/films 20 years ago. I know, I was there.
  - ocharles 11y ago
    I'm aware of that. You didn't however have such a reliance on cars, nor the convenience afforded to having a car (e.g., the popularity of drive-thrus now, which were only getting started in 1980). There is such easy access to things like Netflix and Steam - it is very easy these days to waste entire days away without even noticing.
    - winthrowe 11y ago
      1980 was thirty-five years ago, not twenty.
AuLaVache 11y ago
It's simple: Eat more fat. The bacteria that processes fat (bacterocides) obviously needs fat to survive. By not eating fat you effectively kill your ability to process fat. The rise in low fat products, coincides with the rise in obesity. One is not the cure for the other -it's the cause of the other.
citeguised 11y ago
Oh, so the laws of physics changed? Wow! No but seriously, this is a terrible article. As soon as you read »…a professor of _kinesiology_ and health science…« you know the statements are coming from people who believe in esoteric pseudoscience. If your burn more energy than you take in, you lose weight. Everything else doesn't make sense. You can get fat by eating 5000 calories worth of paprika every day. Statements like these only help people who have weight-problems to have an excuse not to do anything about it.
- dasil003 11y ago
  I don't especially want to defend the article but this whole first-law-of-thermodynamics approach to explaining weight gain is definitely the most useless idea that somehow always rears its head around here. It's not only useless on its face since how much we eat is moderated by satiety mechanisms rather than weights and measures, but it also ignores the complexity of nutrition and metabolism and the fact that weight has only a loose correlation to overall health. As much as you're not going to fix your health by reading superficial linkbait articles, you also will not do it by taking a smug reductionist view that allows you to dismiss the subtleties of nutrition which still remain frustratingly beyond the reach of conclusive hard science.
  - citeguised 11y ago
    > how much we eat is moderated by satiety mechanisms No, it's moderated by our fork. It also means being hungry a lot and keeping exact track of your calories, just like poor people need to track their expenses. (Been there done that with both money and weight) The »subtleties of nutrition« don't matter if you are huge (BMI > 30) and want to get down to a healthy level. Once you are there you still can optimize and find out what works best for you.
    - dasil003 11y ago
      I see, so fat people just need to knuckle down and starve themselves until they are reasonable weight and only then start to pay attention to the overall function of the human organism and their particular incarnation of it? That seems utterly backwards if not willfully ignorant.
learnstats2 11y ago
One potential explanation is that nutritional information is being manipulated more effectively by food manufacturers.
erdewit 11y ago
This study relies on the NHANES data which is self-reported: Respondents have to recall what they ate. So an alternative and more likely explanation is that people are far better at deluding themselves than they used to be.
- vixen99 11y ago
  Yes and moreover we have statements such as " it’s harder for adults today to maintain the same weight as those 20 to 30 years ago did, even at the same levels of food intake and exercise." and "In other words, people today are about 10 percent heavier than people were in the 1980s, even if they follow the exact same diet and exercise plans." These conclusions from a study with 36,000 people out of some 300 million Americans?
- white-flame 11y ago
  I would also assume that there's less structured eating schedules in homes now than there used to be, which would make it more difficult to catalog exactly what was ingested.
- JeremyNT 11y ago
  Even the methodology for acquisition of the self-reported data used in this study has changed over the years. > In NHANES I (1971–1975) and NHANES II (1976–1980), in-person interviews were used to obtain self-reported dietary information via a 24-h dietary recall questionnaire that assessed food and beverage intake for weekdays only. In NHANES III (1988–1994), dietary information was obtained through a self-reported 24-h dietary recall using a computer-assisted, automated, interactive method for any day of the week. In NHANES 1999–2002, a multiple-pass computer-assisted dietary interview format was used to collect detailed self-reported information about all foods and beverages that were consumed the day prior to the in-person interview (weekday or weekend). In NHANES 2003–2008, 24-h self-reported dietary recalls were performed twice (3–10 days apart) using an automated multiple pass method. I'm highly suspect of this one. This seems like an interesting avenue of exploration, but this data seems too weak to make broad claims from.
DanBC 11y ago
There's a bunch of stuff that might be going on here. People mostly don't know what they're eating. They don't know the calorie content; they don't know the macro / micro nutrient content. They don't know how much they're eating, nor how much they should be eating. Food (and I have nothing to base this on) feels more engineered and feels like it's deceptively marketed (gummy bears being sold as "FAT FREE FOOD!" is a scumbag tactic). We're seeing similar levels of broscience ("Avoid all sugar!") as we saw in the 80s ("Avoid all fat!") and it's probably not helpful. I'm also interested in what they corrected for. Did they correct for increased prescribing of psychiatric meds? The US has a lot of "off label" prescribing of such meds; prescribing of these meds has increased dramatically since the 1990s; many of them list increased appetite and weight gain as side effects. (And the weight gain is not just a function of increased appetite).
jensen123 11y ago
I seem to gain weight when I eat wheat. When I eliminate wheat, my weight is stable. I found a study about how wheat interferes with leptin (the hormone that makes us feel full): http://www.biochemj.org/content/410/3/595 http://www.biochemj.org/content/410/3/595 I think I've read several places that the wheat we eat today is significantly different from the wheat people ate in the old days. If I remember correctly, our wheat contains much more gluten, since high-gluten wheat makes bread fluffier etc.
- Litost 11y ago
  I was curious about this, as a relation has gluten intolerance. This reckons that the gluten content of wheat hasn't really changed: http://nogluten-noproblem.com/2014/03/has-the-gluten-content-of-wheat-increased-over-time.html http://nogluten-noproblem.com/2014/03/has-the-gluten-content... And entertainingly this reckons increasingly industrialy generated wheat is now so devoid of any nutrients, even pigs won't eat it? http://www.grainstorm.com/pages/modern-wheat http://www.grainstorm.com/pages/modern-wheat Is it just me or is it becoming increasingly more difficult to get the truth on any matter, because you're wading through so many layers of human generated FUD (Fear, Uncertainty and Doubt)?
  - mithras 11y ago
    I have the same issue. So much FUD articles around on nutrition. Sticking to scientific studies works but it's a lot more effort.
  - jensen123 11y ago
    Thank you for this. Then I will stop repeating this gluten myth.
klunger 11y ago
It was bizarre that the article did not mention trends in other behaviours that effect weight, like sleep and stress level. Millenials are arguably more stressed out than people the same age a generation ago, due to increased student loan debt, unstable job market and poor job security. This constant stress of course contributes to how well your body can maintain a healthy weight. There should be a rigorous study comparing relative stress levels over generations, but it is not hard to imagine that this is broadly true.
- timetravel3r 11y ago
  This is very true. And commute distances. I've found my time allocated to exercise goes down with increased commute time. I've also found my commute distances go up with home prices, as i need to go further out to afford the same amount of space.
acd 11y ago
Compare sugar intake now and 20 years ago, sugar metabolizes to fat in the body. So that food is fat free, but high in sugar leads to the same thing in the body anyway. Also look at the sizes of portions, soda and food packages they have all increased too. Fast food consumption which is high in sugar and fat has also increased. Lab rats has shown to be as addicted as cocaine on sugar http://www.forbes.com/sites/jacobsullum/2013/10/16/research-shows-cocaine-and-heroin-are-less-addictive-than-oreos/ http://www.forbes.com/sites/jacobsullum/2013/10/16/research-...
- bad_user 11y ago
  I've just read "In defence of food". It's a little sensationalist, but the author makes a good point that we've been blaming this or that nutrient and in the process we've become more and more unhealthy. Amongst others we blamed cholesterol, we blamed fats, then saturated fats, now we're starting to blame carbohydrates. The problem starts from the reductionist science being applied, coupled with the constant lobbying of the food industry of course. What happens is that nutrition is an incredibly complex subject and nutritionists can only blame what they can currently measure. The result is a whole industry of processed foods that have lost their nutritional value. And for the food industry, that's OK because processed foods are more profitable. The problem is not naturally occurring sugar. The problem is high fructose corn syrup and (to a lesser extent) sucrose and the current practice of injecting these substances in processed foods, because these sugars are fooling our senses and create addiction. But we are talking about refined carbohydrates. The sugar in fruits is totally fine and in fact there are signs that we don't eat enough fruits. But why stop at sugars? Margarine was certainly a bad idea, as was every other idea that the nutritionists' community ever had. So really, if you want an enemy, that's certainly processed foods and the weakest cult-like science that human kind ever practised. To this day doctors are still advising patients to avoid saturated fats, even though there's zero evidence of saturated fats provoking cancer or heart disease or obesity. To this day you can see low-fat products, like low-fat milk that's artificially coloured and enriched with powdered milk, being sold because of health claims. Expect to see Omega-3 in bananas.
- tgb 11y ago
  The whole point of this study was that the difference exists even after controlling for micronutrients. Your low-fat high-sugar theory is incompatible or at least insufficient.
marincounty 11y ago
I'm kind of tired of these studies. They don't know why we are fatter. Personally, I think it's a lot of factors, and maybe even a virus? That aside, moderate exercise has so many positive benefits, why not do a little. I have no idea if it helps lose weight, but working up a slight sweat daily, has helped me greatly over the years. Not so much with weight, but psychologically. Yes--it's been my major drug since 8th grade. (It seems like 8th grade is when society injects those needles of stress, on so many levels?) I do other drugs, but exercise has been my major addiction for years. I don't tell people. I'm actually embarrassed by it. I've been fat and skinny. When I was fat, I didn't need to exercise as much in order to get the psychological benefits from exercise--in my case, it's always been some kind of cardio. My point is if you don't feel well, and you don't have any physical reason not to exercise; give it a shot. You don't need to do marathons; just walk(fast, or slow, or run small distances--then walk). Exercise until you work up a good sweat.(I need at least 45 minutes now, but when I was heavier I just needed 20 minutes/daily. That was a hidden benefit from being overweight?) I guarantee after a little while, you will feel better. You might lose weight. You might improve your blood numbers. I can guarantee you will feal better, and will get to like the slight muscle pain the next day. In my case I need to exercise daily. Some people get the psychological boost from just exercising occasionally. I think your occupation plays a role? My father worked construction and was always sweaty. I would never tell him to exercise. You will come to like the slight muscle pain the next day. I've been around people who don't have any pain the next day, but not me. I ache when I arise. Yes, your legs/body will hurt when you wake up the next day. I've never had anyone tell me to be be prepared to hurt the next day, but the hurt becomes a good hurt with time. I've always hated getting up in the mornings, and don't know if my exercise régime is to blame, but once I get going; I'm glad I worked up a sweat the previous day. (I sugesseted sweating because, in my experience, if I don't sweat profusely; I don't get the same psychological bump. Maybe it's psychosomatic--I am a bit of a Nut?
- saiya-jin 11y ago
  nonono. no. you don't get it. we need to find something, someone else evil to blame. it's not us, cannot be us, we're perfect, and we won't change just because it makes sense. It's like junk food is a complete mystery for last 20 years, and we don't have a free will and we are not actually choosing what we buy or eat. the fact that sweet stuff is not healthy was known to me as a kid 25 years ago, without all the science. Everybody knew it. I'll say something many won't like - people got weak, not only physically, but mentally. We cannot handle pain that was common before, we frown upon hard physical work, because its well... hard. We seek professional challenges, but other, more important ones, are often sidelined. Also, completely agree with you. Doing sports, anything that makes your heart pumping and your body sweating like pig is by far the best thing one can do for his/her health. Regularly/often is the key, the only true key. Unless one is paraplegic, there is no excuse good enough to be valid. But guess what - it's hard :)
netcan 11y ago
I have no particular expertise in this area, but I've been making the "we don't know why people are fat" argument to whoever will listen for a while. Doctors (socially, not at an appointment FWIW), academics… I'm actually quite surprised how often they've been thinking along the same lines and/or they are convinced by the general idea. basically: People have been getting fatter, to pathological levels for quite a while. The phenomenon is global. The conventional explanation is too much for and not enough exercise, caloric surplus. This is not nonsensical. We know that caloric restriction leads to weigh loss. We can also see that various other approaches can result in weight loss. Carbohydrate restriction, for example. But, this doesn't give us a complete (or possibly even relevant) answer. This requires another 'why' and a 'why now.' All it takes is a small sustained caloric surplus over long periods to reach obesity. People have had access to these calories, in large populations or in pockets for a long time. There have been periods of regional caloric wealth and certainly periods of caloric wealth within subcultures/classes. If caloric surplus is the key idea, why do we have these caloric surpluses today. There were sedentary workers even in ancient times, certainly in the 20th century. Today's sedentary worker is fatter than yesteryear's. Today's carpenter is fatter than a carpenter in 1972. Why? A carpenter in 1972 had plenty of access to calories, similar physical lifestyle. IMO, this is an epidemic and we need an explanation that works at epidemic levels. We need to explain the change in populations weight, not differences in individual's weight. The answer to the first is probably different to the second. "Gut biome" may be an answer. Antibiotics. Parasites are another interesting possibility. In any case, I don't think it's coincidence that fad diet books and other pop science is so successful. We do not have an answer from science. I don't eves think the right question is usually asked. Why did we all get so fat?
- philliphaydon 11y ago
  We don't know? We do know and have known for a long time...
- haywirez 11y ago
  Didn't read the study, but part of the explanation could be that people spend less time outside and are generally in warmer environments. Omnipresent AC, different clothing, better insulation all means that the body burns less calories to keep itself warm.[0] "[...] in the U.K., average living room temperatures rose from 64.9F/18.3C in 1978 to 66.4F/19.1C in 2008 and bedroom temperatures increased from 59.36F/15.2C to 65.3F/18.5C."[1] [0][1] http://hypothermics.com/2011/02/ch-ch-changes/ http://hypothermics.com/2011/02/ch-ch-changes/
greatthanks 11y ago
The actual conclusion is hidden in the middle of the text: eat less meat First of all b/c its contribution to health is doubtable in general and at current times in particular.
- Erwin 11y ago
  That's not what I got out out if; they mentioned: avoid chemicals in food or packaging (i.e. eat organic - no antibiotic/hormone laden meat) - avoid artificial sweeteners - avoid antidepressant and unnecessary medication. Meat is fine, as long as you don't eat something too industrial.
  - greatthanks 11y ago
    no - (red) meat is not fine: http://lmgtfy.com/?q=%22red+meat%22+site%3Anature.com http://lmgtfy.com/?q=%22red+meat%22+site%3Anature.com
cdnsteve 11y ago
Does this study take into account the exponential growth of portion size? Food portions in the USA are out of control, four times larger than the 1950's. http://www.huffingtonpost.com/2012/05/23/portion-sizes-infographic_n_1539804.html http://www.huffingtonpost.com/2012/05/23/portion-sizes-infog...
- mattlutze 11y ago
  "They found a very surprising correlation: A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher. In other words, people today are about 10 percent heavier than people were in the 1980s, even if they follow the exact same diet and exercise plans." ^ The 3rd paragraph of the article.
  - maxerickson 11y ago
    It can still be explained by people eating more. Take a 1980 individual that had been eating a bmi23 diet and start feeding them a bmi26 level of calories and they will probably gain weight. Take a 2015 individual's diet from bmi26 to bmi23 and they will probably lose weight.
    - cellshade 11y ago
      It says the same number of Calories in the post directly above.
      - maxerickson 11y ago
        Sure, but it isn't the same person. If my bmi23 diet is 2000 calories and I eat 2000 calories, I will probably have a bmi of 23. If my bmi23 diet is 1800 calories and I eat 2000 calories, I will probably have a higher bmi. I guess a clearer way to say what I am getting at is that bmi is descriptive, not predictive, so a shift in the bmi maintained by a given calorie intake could be explained by a shift in the habits of the population, so that the modern group achieves a given bmi at higher calorie intakes.
codexjourneys 11y ago
I suspect the answer has to do with the microbiome and its cumulative response over decades to antibiotics and tiny changes introduced in food (shifts in cooking oils, dairy product additives, even animal feed that then indirectly impacts our own microbiome when we eat meat or eggs or dairy, etc.). The problem is that studies on the microbiome tend to be limited and recent. Long-term studies are especially lacking. What we do have indicates the microbiome may be vital to not just digestion but also our immune system function, emotional well-being and weight. Probiotics might be helpful here, but in no way are we close to an exact science on the microbiome.
dr-g 11y ago
Is evolution via natural selection at play here? Or is the timespan too short for such a clear change to be seen?

140 points by fisherjeff 11y ago

hughw 11y ago

Well sure, but we're twenty years older, too.

hughw 11y ago
No joking on HN!

personjerry 11y ago

Weight gain is simple: calorie intake - calorie expenditure. The amount of calories in our food tends to go up over 20 years. Doing the same activities consumes the same amount of calories after 20 years. Thus we would have more caloric surplus, and likely gain more weight than people 20 years ago with less caloric food. Pretty simple imo.

zacwest 11y ago
From the article you're writing a comment to: > A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher.
- toomuchtodo 11y ago
  Its strange really. I'm on a ketogenic diet, and hear people preach the caloric balance constantly, that it doesn't matter what my macros are as long as I consume less calories than I burn daily. Yet, I consume close to my previous garbage diet calories and I lose about 2-3lbs/week due to my high fat/moderate protein/very low carb (<15g/day of carbs) diet. Go figure, it appears that caloric energy balance isn't the only factor.
  - jfoutz 11y ago
    It's an absolute limit. Perhaps there are specific modes that are a a few percent more or less efficient. Nonetheless, you eat less than you burn, you lose weight.
    - im3w1l 11y ago
      Him burning it is not the only possibility. Maybe he is shitting it out? Maybe bacteria in his body are burning it for him?
      - toomuchtodo 11y ago
        Gut flora is a big possibility as to the discrepancy. I imagine there are some gut flora that are more adapt at breaking down carbohydrates than others, saturating the body in unnecessary energy to absorb.
  - com2kid 11y ago
    From someone who's been doing keto for several years now. A: Pre-Keto, odds are you we underestimating how many calories you were eating. Unless you were tracking every single thing you ate, there is a high probability you just didn't realize how many calories you were consuming. B: It is super hard to over eat on Keto. It is possible, take lots of liquid calories in (heavy cream can do this easily!), and there are some other real screw ups, but eating 3000 calories of steak is pretty damn hard. C: What you are reporting is common for people who have a lot of weight to lose. At some point it becomes a lot harder, at first you just have to sort of watch things, then you eventually do have to count calories. (Especially if you want a six pack, holy crap do you have to count calories!)
    - toomuchtodo 11y ago
      Thanks for that info! Did you ever experience symptoms similar to eye fatigue? I think I might be not consuming enough sodium and/or potassium; I'm going to up my doses of both to test my theory.
- tdylan 11y ago
  They didn't control the energy expenditure to any meaningful degree. Essentially worthless.
  - _delirium 11y ago
    The point of the study, from what I can tell, was to show that calories+macronutrients+exercise, the three main current targets of anti-obesity intervention, fail to account for a large portion of observed population-scale changes. They aren't arguing generally against total energy balance being involved, only that those three quantities don't constitute a sufficient measure of total energy balance. The implication would be that there are likely other sources of variation, e.g. changes in digestion, metabolism, etc. (the study doesn't really go out on a limb and speculate on that part).
- tomp 11y ago
  That doesn't mean much... Maybe people who eat the same now ate more in the past, which is why they're still fatter.
hspak 11y ago
I'd recommend reading Good Calories, Bad Calories by Gary Taubes. He explains how this is not really the case. It was written back in 2007; I'm sure there's more research out there to prove this point.
- tdylan 11y ago
  From what I've seen Garrys hypothesis was proven wrong by Alan Aragon.
  - billjings 11y ago
    Taubes' end-of-the-book hypothesis about Atkins diets and the like isn't that great, but the whole initial portion of the book trashing the fat hypothesis is great. If you enjoy scientific writing, I promise that you will get a lot out of it, whether you agree with him or not. He's a fantastic writer, and an exhaustive researcher.
bemmu 11y ago
While that's also certainly true, the article says that in this case the calorie intake was the same. They were guessing gut bacteria could be different. Maybe the formula is calories in * bacteria efficiency - calories out?
Guzba 11y ago
A person gains weight because they intake more calories than they expend. Certainly. A room gets more crowded when more people enter than exit. Obviously true. Neither of these statements tell you why that is happening though, and that is important thing. So, why are people eating more calories? Or, since the articles says they aren't, could the sources of calories matter? (They do.)
- theophrastus 11y ago
  This simple thermodynamic model intake minus expenditure leaves out (at least) one dynamic metabolic feature: this engine can change its tendency for storage (weight gain) in a single organism or in a community of organisms given time. A change in the community storage tendency is what is alluded to in the linked article. That is, the organism can allow the excess calories to pass on by, or it can store it as fat (or glycogen). This, for instance, is the holy grail of weigh managing pharmaceuticals: to discover those effectors of "now store every un-expended calorie (as fat)". So finally it's something like: intake - expenditure = available for storage, but might not be stored.
  - DennisP 11y ago
    And the other variable is how well the body turns fat reserves back into available energy. If that mechanism is inefficient then the equilibrium will be higher body fat. People seem to have an idea that every human body can just instantly burn however much fat it needs to burn to meet demand. It seems more likely that there's a limit to how fast the body can burn fat, which for some people is unusually low, and that if there's not enough energy available you'll be forced by thermodynamics to move less, think poorly, and produce less body heat.
com2kid 11y ago
There is a type of seaweed that if your average American eats it, there are zero calories absorbed. If most Japanese citizens eat it, they will absorb calories from it. There is a gut bacteria common in the Japanese population that extracts calories from this type of seaweed. "calories in" is that calories that went down your throat. It is calories that your body was able to digest, and "your body" includes many types of bacteria that are unique to each person and also unique to different population groups (meaning that some populations share commonalities in gut flora). It is possible that certain antibiotics have wipe out some types of gut flora, allowing others to proliferate more. That alone could increase calorie absorption. (Or cause a host of other problems!) It is possible that having a diet too heavily reliant upon one type of food results in an imbalance of some type. The problem is, this is a brand new area of research and we just don't know yet. But it is sure as heck known that it is more complicated than "calories in food down the throat".
- tdylan 11y ago
  Link to data/research?
  - com2kid 11y ago
    http://www.npr.org/templates/story/story.php?storyId=125675700 http://www.npr.org/templates/story/story.php?storyId=1256757... Actual suspected caloric difference is minimal, after all, well, it is seaweed, not a very dense food stuff. :) I'm not going to link to antibiotics causing gut flora problems, it is well known and responsible doctors actually can prescribe a nice little compact pill full of gut bacteria that replaces the ones wiped out as a side effect of antibiotics. The stuff about a biased diet messing up gut bacteria is also hard to find research on (I've read it, but it is a PITA to find again). Basically different bacteria specialize in breaking down different types of food. If you have a diet lacking in some major food group, that stock of bacteria runs low. Vegans can have this issue if they go back to eating meat. There is typically some tiny supply of the needed bacteria left and the population is restored after awhile, but the initial few hamburgers can be somewhat uncomfortable.
    - 11y ago
billjings 11y ago
Right, but physiology, psychology, and even sociology can all influence both calorie intake and expenditure. Send a kid to football camp, and they'll eat more and spend more calories. So: hard problem. Not strictly a technical problem, either.
stevebmark 11y ago
You think it's "pretty simple" because you haven't done any in depth research on the subject. Telling people to eat less and move more to lose weight is a recipe for failure. You have no qualifications but keep repeating the calories in calories out mantra. Until you've told this to hundreds of your patients and watching hundreds of them fail despite your useless advice, stop trying to shove your foot into the nutritional science door.
- nightski 11y ago
  While I respect the knowledge of doctors, often the "wisdom" they have does not agree with one another. We need a better approach than gut feeling. I highly doubt simply telling a mantra like calories in vs. calories out to patients is going to change their behavior much (does the doctor spend months in the home of a patient helping them follow their advice?). It's not a very scientific way to go about it.
PhasmaFelis 11y ago
> The amount of calories in our food tends to go up over 20 years. RTFA, please. Paragraph five, specifically.
deleted 11y ago
[deleted]

im3w1l 11y ago

I do not have access to the fulltext but from the abstract, it seems they may only have included structured leisure time physical activity like playing football one hour every Monday (what could "Physical activity frequency data ... in 14,419 adults between 1988 and 2006" plausably include?) I would think there is less unstructured physical activity nowadays. Both at home and at work.

deleted 11y ago

[deleted]

xiaoma 11y ago

> A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher. I think the recent obsession with macronutrients is a big part of the problem. I'm not sure if the macronutrient ratio I eat has changed much from when I was growing up with my grandmother's cooking, with the exception of three failed experiments with low carb diets and a couple of other small experiments. The thing is that in the 80s, as a kid, I was more likely to be eating traditional American staples, like corn flakes or oatmeal and a banana for breakfast, and a typical meal would include meat, potatoes and a green vegetable. I drank some soda, but also about a quart of milk a day. Now I tend to eat out 9 times a week instead of 2 and I eat a lot more processed food unless I make a concerted effort not to. I avoid soda for the most part, but on the whole there's a lot more stuff in my diet that my great-grandparents wouldn't have recognized as food. I don't remember the last time I drank milk. Surely eating home baked bread or a piece of fruit isn't the same as eating a snack bar, eating meat isn't the same as drinking muscle milk, and fatty fish doesn't equate to pork rinds, etc. Macronutrient ratios just don't tell the whole story or even most of it.

com2kid 11y ago
I agree, the macros look sort of the same, but the source of those calories is much different. Just the types of cooking oil we use has changed a lot. Look at what goes into cookies now. It used to be butter, now I've seen recipes with canola oil. (if anyone tells you to use canola oil in your baked goods, ignore them and use butter!) There is evidence that gut bacteria is passed down from generation to generation, we could very well be seeing a delayed effect from public policy and health decisions made around the time the previous generation was growing up. oops. I am sort of on the fence about processed foods. A lot of canned food was eaten previously, fresh vegetables were not available year round, but a lot of the canning was done at home in glass jars. I am not one to be paranoid, but now all our canned food comes in coated aluminum cans. We have a few decades of aluminum cans being coated on the inside with BPA. It is know known that BPA can have harmful effects that take a long time to manifest. The point is, there are a lot of potential culprits, and it is going to take a long time to figure out what state unbridled capitalism has left public health in.

DiabloD3 11y ago

I don't have access to the study, but I suspect it doesn't say what The Atlantic is saying it's saying. I lost weight: I went from 340 pounds to 214 pounds in exactly a year, and then bottomed out at 184 eventually (I've been purposely trying to gain muscle lately, which has been causing my weight to meander in the 190s since then). My caloric intake hasn't changed in a way that can explain such a weight loss. I went from eating 1500-2000 calories a day to 1500-2000 calories a day (as in, no useful change, nothing that can explain 126 pounds in a year, disproportionately more of it towards the start than the end). Now, what I did change was drop all grains (grains, cereals, pastas, soy, rice), drop refined sugars (I still use coconut and true raw cane sugars (Muscovado, Barbados, or Turbinado) or straight up raw honey; all very sparingly, and corn syrup is banned in my house), dropped seed oils (no more "vegetable", soy, corn, or canola oils; replaced with coconut and olive oil, or leftover bacon fat when I have it), and legumes (I'm allergic to peanuts, and don't care for beans, so the only thing I lost there is peas; soy is a legume, but I include it in with grains due to how it is typically treated culinarily, and thus already banned in my house). So, given my experience, people are fatter because of reasons that cannot be explained by calories, such as chemicals in the things I quit eating causing unusual weight gain and halting the natural process of us burning endogenous fat. And it isn't like I'm the only person who did this, it is estimated over a million people have tried Paleo or some variant thereof and have significantly lost weight if they were overweight as long as they stuck with the lifestyle. Side note: I went from 340 to 214 with chronically under-exercising. I still chronically under-exercise to a point, even though I now lift weights and try to go on daily walks. I still don't get the high other people seem to get from exercising. So, you can't use "increased caloric burn" as why I lost so much weight, it just wasn't there.

johnthedebs 11y ago
How carefully were you tracking calorie intake? It's notoriously difficult and I simply don't believe you ate 1500-2000 calories at 340lbs and didn't lose weight (not that you need to convince me). In any case, congrats on the achievement!
- DiabloD3 11y ago

abrons 11y ago

The article mentions prescription drugs but doesn't mention a widely used over the counter one: nicotine. US smoking rates are down about 50% over the last 20 years. (That's overall, I couldn't find any details by cohort.)

jl6 11y ago
Is the suggestion that people are channelling addictive behaviors from smoking to eating?
- damian2000 11y ago
  Smoking reduces your appetite, leading to less eating and less weight. http://www.npr.org/2011/06/09/137085989/the-skinny-on-smoking-why-nicotine-curbs-appetite http://www.npr.org/2011/06/09/137085989/the-skinny-on-smokin...
  - jacobolus 11y ago
    Nicotine (without smoking) also has that effect, even in low doses. Actually there are two parts: it reduces appetite, and also raises the resting metabolic rate, cf. e.g. http://www.ncbi.nlm.nih.gov/pubmed/2773833 http://www.ncbi.nlm.nih.gov/pubmed/2773833
- deleted 11y ago
  [deleted]
desdiv 11y ago
Good thinking, but the researchers already adjusted for smoking status [0][1]. [0] http://i.imgur.com/mQZ1ST9.png http://i.imgur.com/mQZ1ST9.png [1] http://i.imgur.com/Hi1x4Ab.png http://i.imgur.com/Hi1x4Ab.png

ejcx 11y ago

Health studies, especially when reported by some article in som publication without an original source are a mess. I personally am extremely skeptical of what the Atlantis says the findings of the paper are. I lost 50 lbs while eating a box of pop tarts per day while counting macros. It's anecdotal but that's the basis for my beliefs, and a lot of science supports it. One issue with health studies is how data is collected. Numerous studies have shown that a huge number of people are incapable of accurately tracking the number of calories they consume per day, and consistently under report their numbers. I believe it, it's hard in today's eat out culture. So...how sure are we that people were consuming the same number of calories? This is just one issue. There are tons more. If you happen to be in this thread and you are looking for health advice, my recommendation is to head to /r/fitness and read the FAQ.

NVI 11y ago

The original article is behind a paywall: http://www.obesityresearchclinicalpractice.com/article/S1871-403X(15)00121-0/abstract http://www.obesityresearchclinicalpractice.com/article/S1871.... Summary: Background To determine whether the relationship between caloric intake, macronutrient intake, and physical activity with obesity has changed over time. Methods Dietary data from 36,377 U.S. adults from the National Health and Nutrition Survey (NHANES) between 1971 and 2008 was used. Physical activity frequency data was only available in 14,419 adults between 1988 and 2006. Generalised linear models were used to examine if the association between total caloric intake, percent dietary macronutrient intake and physical activity with body mass index (BMI) was different over time. Results Between 1971 and 2008, BMI, total caloric intake and carbohydrate intake increased 10–14%, and fat and protein intake decreased 5–9%. Between 1988 and 2006, frequency of leisure time physical activity increased 47–120%. However, for a given amount of caloric intake, macronutrient intake or leisure time physical activity, the predicted BMI was up to 2.3 kg/m2 higher in 2006 that in 1988 in the mutually adjusted model (P < 0.05). Conclusions Factors other than diet and physical activity may be contributing to the increase in BMI over time. Further research is necessary to identify these factors and to determine the mechanisms through which they affect body weight.

agravier 11y ago

It's due to sugar in the vast majority of cases. Some starting point: https://www.youtube.com/watch?v=dBnniua6-oM https://www.youtube.com/watch?v=dBnniua6-oM

agravier 11y ago
I'd like some explanations for the downvotes. What I wrote is documented and I provide a link to a good source of explanations.
- citeguised 11y ago
  The explanation is that facts don't matter for some people.

pazimzadeh 11y ago

I hope that they controlled for factors like smoking cigarettes.

raverbashing 11y ago
This might be a significant factor indeed (including passive smoking)
desdiv 11y ago
They have [0][1]. [0] http://i.imgur.com/mQZ1ST9.png http://i.imgur.com/mQZ1ST9.png [1] http://i.imgur.com/Hi1x4Ab.png http://i.imgur.com/Hi1x4Ab.png

mutagen 11y ago

Humans aren't the only ones gaining weight, animals are too: Fluffy article: http://news.discovery.com/animals/fat-pets-obesity-weight.htm http://news.discovery.com/animals/fat-pets-obesity-weight.ht... Nature article: http://www.nature.com/news/2010/101124/full/news.2010.628.html http://www.nature.com/news/2010/101124/full/news.2010.628.ht... Paper focusing on both lab animals (where diet is strictly controlled), pets, and feral rats living among humans: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081766/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081766/

hoodoof 11y ago

The air is fatter in the 21st century.

cwp 11y ago

I've noticed the same thing geographically. Twice now, I've taken a "sabbatical" and moved to Quito, Ecuador for a year to be near family. Both times, I lost weight when I arrived, stabilized at a leaner equilibrium, then gained the weight back when I returned to North America. Could be nutritional, could be bacterial, could social. Whatever it is, the effect is dramatic.

hajrice 11y ago
Noticed the same exact thing when I go to Europe, vs. America I think the article mostly applies to America. American food is just fattening
- danlindley 11y ago
  The study factored in the nutritional value of the food, so your comment seems counter to their findings. "...eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher."
  - tnorthcutt 11y ago
    The study factored in the nutritional value of the food The study factored in the macronutrients, but that's not all that matters when it comes to food.
  - emp_zealoth 11y ago
    Except the calories are obsolete (meaningless) A lot of the food now is higly processed, ground to microns, resulting in way higher "usable engergy" that can be extracted. Especially the "cheap" food - full of awful sugars, stabilised fats or other junk, gelatine, mechanically abused.
    - pflanze 11y ago
      Your answer may look unscientific (hand-wavy, with the word "meaningless" being too strong, that's how I explain the downvotes), but I guess if eating is (partially) feeding gut bacteria, then the micro structure of the food could well matter a lot with regards of which kinds of bacteria it promotes and which it weakens, and hence change the composition of the biome.

vph 11y ago

You can't eat the same foods people ate 20 years ago. The cows aren't the same. The chickens aren't same. Cows and chickens today are more obese and eat more antibiotics than they used to be.

elktea 11y ago
It's due to what we feed them, as well. We even feed corn to farmed Salmon, which makes their Omega 3&6 ratios the opposite of what they naturally are.

ocharles 11y ago

Does this study factor in the huge life style changes over 20 years? Far more access to cars, and far more spending entire days sitting down (computer jobs, Netflix binge watching, etc). A lot of how we live has changed in 20 years, I'm inclined to think the problem lies there, not in environmental factors.

weego 11y ago
We had cars and tv/video games/films 20 years ago. I know, I was there.
- ocharles 11y ago
  I'm aware of that. You didn't however have such a reliance on cars, nor the convenience afforded to having a car (e.g., the popularity of drive-thrus now, which were only getting started in 1980). There is such easy access to things like Netflix and Steam - it is very easy these days to waste entire days away without even noticing.
  - winthrowe 11y ago
    1980 was thirty-five years ago, not twenty.

AuLaVache 11y ago

It's simple: Eat more fat. The bacteria that processes fat (bacterocides) obviously needs fat to survive. By not eating fat you effectively kill your ability to process fat. The rise in low fat products, coincides with the rise in obesity. One is not the cure for the other -it's the cause of the other.

citeguised 11y ago

Oh, so the laws of physics changed? Wow! No but seriously, this is a terrible article. As soon as you read »…a professor of _kinesiology_ and health science…« you know the statements are coming from people who believe in esoteric pseudoscience. If your burn more energy than you take in, you lose weight. Everything else doesn't make sense. You can get fat by eating 5000 calories worth of paprika every day. Statements like these only help people who have weight-problems to have an excuse not to do anything about it.

dasil003 11y ago
I don't especially want to defend the article but this whole first-law-of-thermodynamics approach to explaining weight gain is definitely the most useless idea that somehow always rears its head around here. It's not only useless on its face since how much we eat is moderated by satiety mechanisms rather than weights and measures, but it also ignores the complexity of nutrition and metabolism and the fact that weight has only a loose correlation to overall health. As much as you're not going to fix your health by reading superficial linkbait articles, you also will not do it by taking a smug reductionist view that allows you to dismiss the subtleties of nutrition which still remain frustratingly beyond the reach of conclusive hard science.
- citeguised 11y ago
  > how much we eat is moderated by satiety mechanisms No, it's moderated by our fork. It also means being hungry a lot and keeping exact track of your calories, just like poor people need to track their expenses. (Been there done that with both money and weight) The »subtleties of nutrition« don't matter if you are huge (BMI > 30) and want to get down to a healthy level. Once you are there you still can optimize and find out what works best for you.
  - dasil003 11y ago
    I see, so fat people just need to knuckle down and starve themselves until they are reasonable weight and only then start to pay attention to the overall function of the human organism and their particular incarnation of it? That seems utterly backwards if not willfully ignorant.

learnstats2 11y ago

One potential explanation is that nutritional information is being manipulated more effectively by food manufacturers.

erdewit 11y ago

This study relies on the NHANES data which is self-reported: Respondents have to recall what they ate. So an alternative and more likely explanation is that people are far better at deluding themselves than they used to be.

vixen99 11y ago
Yes and moreover we have statements such as " it’s harder for adults today to maintain the same weight as those 20 to 30 years ago did, even at the same levels of food intake and exercise." and "In other words, people today are about 10 percent heavier than people were in the 1980s, even if they follow the exact same diet and exercise plans." These conclusions from a study with 36,000 people out of some 300 million Americans?
white-flame 11y ago
I would also assume that there's less structured eating schedules in homes now than there used to be, which would make it more difficult to catalog exactly what was ingested.
JeremyNT 11y ago
Even the methodology for acquisition of the self-reported data used in this study has changed over the years. > In NHANES I (1971–1975) and NHANES II (1976–1980), in-person interviews were used to obtain self-reported dietary information via a 24-h dietary recall questionnaire that assessed food and beverage intake for weekdays only. In NHANES III (1988–1994), dietary information was obtained through a self-reported 24-h dietary recall using a computer-assisted, automated, interactive method for any day of the week. In NHANES 1999–2002, a multiple-pass computer-assisted dietary interview format was used to collect detailed self-reported information about all foods and beverages that were consumed the day prior to the in-person interview (weekday or weekend). In NHANES 2003–2008, 24-h self-reported dietary recalls were performed twice (3–10 days apart) using an automated multiple pass method. I'm highly suspect of this one. This seems like an interesting avenue of exploration, but this data seems too weak to make broad claims from.

DanBC 11y ago

There's a bunch of stuff that might be going on here. People mostly don't know what they're eating. They don't know the calorie content; they don't know the macro / micro nutrient content. They don't know how much they're eating, nor how much they should be eating. Food (and I have nothing to base this on) feels more engineered and feels like it's deceptively marketed (gummy bears being sold as "FAT FREE FOOD!" is a scumbag tactic). We're seeing similar levels of broscience ("Avoid all sugar!") as we saw in the 80s ("Avoid all fat!") and it's probably not helpful. I'm also interested in what they corrected for. Did they correct for increased prescribing of psychiatric meds? The US has a lot of "off label" prescribing of such meds; prescribing of these meds has increased dramatically since the 1990s; many of them list increased appetite and weight gain as side effects. (And the weight gain is not just a function of increased appetite).

jensen123 11y ago

I seem to gain weight when I eat wheat. When I eliminate wheat, my weight is stable. I found a study about how wheat interferes with leptin (the hormone that makes us feel full): http://www.biochemj.org/content/410/3/595 http://www.biochemj.org/content/410/3/595 I think I've read several places that the wheat we eat today is significantly different from the wheat people ate in the old days. If I remember correctly, our wheat contains much more gluten, since high-gluten wheat makes bread fluffier etc.

Litost 11y ago
I was curious about this, as a relation has gluten intolerance. This reckons that the gluten content of wheat hasn't really changed: http://nogluten-noproblem.com/2014/03/has-the-gluten-content-of-wheat-increased-over-time.html http://nogluten-noproblem.com/2014/03/has-the-gluten-content... And entertainingly this reckons increasingly industrialy generated wheat is now so devoid of any nutrients, even pigs won't eat it? http://www.grainstorm.com/pages/modern-wheat http://www.grainstorm.com/pages/modern-wheat Is it just me or is it becoming increasingly more difficult to get the truth on any matter, because you're wading through so many layers of human generated FUD (Fear, Uncertainty and Doubt)?
- mithras 11y ago
  I have the same issue. So much FUD articles around on nutrition. Sticking to scientific studies works but it's a lot more effort.
- jensen123 11y ago
  Thank you for this. Then I will stop repeating this gluten myth.

klunger 11y ago

It was bizarre that the article did not mention trends in other behaviours that effect weight, like sleep and stress level. Millenials are arguably more stressed out than people the same age a generation ago, due to increased student loan debt, unstable job market and poor job security. This constant stress of course contributes to how well your body can maintain a healthy weight. There should be a rigorous study comparing relative stress levels over generations, but it is not hard to imagine that this is broadly true.

timetravel3r 11y ago
This is very true. And commute distances. I've found my time allocated to exercise goes down with increased commute time. I've also found my commute distances go up with home prices, as i need to go further out to afford the same amount of space.

acd 11y ago

Compare sugar intake now and 20 years ago, sugar metabolizes to fat in the body. So that food is fat free, but high in sugar leads to the same thing in the body anyway. Also look at the sizes of portions, soda and food packages they have all increased too. Fast food consumption which is high in sugar and fat has also increased. Lab rats has shown to be as addicted as cocaine on sugar http://www.forbes.com/sites/jacobsullum/2013/10/16/research-shows-cocaine-and-heroin-are-less-addictive-than-oreos/ http://www.forbes.com/sites/jacobsullum/2013/10/16/research-...

bad_user 11y ago
I've just read "In defence of food". It's a little sensationalist, but the author makes a good point that we've been blaming this or that nutrient and in the process we've become more and more unhealthy. Amongst others we blamed cholesterol, we blamed fats, then saturated fats, now we're starting to blame carbohydrates. The problem starts from the reductionist science being applied, coupled with the constant lobbying of the food industry of course. What happens is that nutrition is an incredibly complex subject and nutritionists can only blame what they can currently measure. The result is a whole industry of processed foods that have lost their nutritional value. And for the food industry, that's OK because processed foods are more profitable. The problem is not naturally occurring sugar. The problem is high fructose corn syrup and (to a lesser extent) sucrose and the current practice of injecting these substances in processed foods, because these sugars are fooling our senses and create addiction. But we are talking about refined carbohydrates. The sugar in fruits is totally fine and in fact there are signs that we don't eat enough fruits. But why stop at sugars? Margarine was certainly a bad idea, as was every other idea that the nutritionists' community ever had. So really, if you want an enemy, that's certainly processed foods and the weakest cult-like science that human kind ever practised. To this day doctors are still advising patients to avoid saturated fats, even though there's zero evidence of saturated fats provoking cancer or heart disease or obesity. To this day you can see low-fat products, like low-fat milk that's artificially coloured and enriched with powdered milk, being sold because of health claims. Expect to see Omega-3 in bananas.
tgb 11y ago
The whole point of this study was that the difference exists even after controlling for micronutrients. Your low-fat high-sugar theory is incompatible or at least insufficient.

marincounty 11y ago

I'm kind of tired of these studies. They don't know why we are fatter. Personally, I think it's a lot of factors, and maybe even a virus? That aside, moderate exercise has so many positive benefits, why not do a little. I have no idea if it helps lose weight, but working up a slight sweat daily, has helped me greatly over the years. Not so much with weight, but psychologically. Yes--it's been my major drug since 8th grade. (It seems like 8th grade is when society injects those needles of stress, on so many levels?) I do other drugs, but exercise has been my major addiction for years. I don't tell people. I'm actually embarrassed by it. I've been fat and skinny. When I was fat, I didn't need to exercise as much in order to get the psychological benefits from exercise--in my case, it's always been some kind of cardio. My point is if you don't feel well, and you don't have any physical reason not to exercise; give it a shot. You don't need to do marathons; just walk(fast, or slow, or run small distances--then walk). Exercise until you work up a good sweat.(I need at least 45 minutes now, but when I was heavier I just needed 20 minutes/daily. That was a hidden benefit from being overweight?) I guarantee after a little while, you will feel better. You might lose weight. You might improve your blood numbers. I can guarantee you will feal better, and will get to like the slight muscle pain the next day. In my case I need to exercise daily. Some people get the psychological boost from just exercising occasionally. I think your occupation plays a role? My father worked construction and was always sweaty. I would never tell him to exercise. You will come to like the slight muscle pain the next day. I've been around people who don't have any pain the next day, but not me. I ache when I arise. Yes, your legs/body will hurt when you wake up the next day. I've never had anyone tell me to be be prepared to hurt the next day, but the hurt becomes a good hurt with time. I've always hated getting up in the mornings, and don't know if my exercise régime is to blame, but once I get going; I'm glad I worked up a sweat the previous day. (I sugesseted sweating because, in my experience, if I don't sweat profusely; I don't get the same psychological bump. Maybe it's psychosomatic--I am a bit of a Nut?

saiya-jin 11y ago
nonono. no. you don't get it. we need to find something, someone else evil to blame. it's not us, cannot be us, we're perfect, and we won't change just because it makes sense. It's like junk food is a complete mystery for last 20 years, and we don't have a free will and we are not actually choosing what we buy or eat. the fact that sweet stuff is not healthy was known to me as a kid 25 years ago, without all the science. Everybody knew it. I'll say something many won't like - people got weak, not only physically, but mentally. We cannot handle pain that was common before, we frown upon hard physical work, because its well... hard. We seek professional challenges, but other, more important ones, are often sidelined. Also, completely agree with you. Doing sports, anything that makes your heart pumping and your body sweating like pig is by far the best thing one can do for his/her health. Regularly/often is the key, the only true key. Unless one is paraplegic, there is no excuse good enough to be valid. But guess what - it's hard :)

netcan 11y ago

I have no particular expertise in this area, but I've been making the "we don't know why people are fat" argument to whoever will listen for a while. Doctors (socially, not at an appointment FWIW), academics… I'm actually quite surprised how often they've been thinking along the same lines and/or they are convinced by the general idea. basically: People have been getting fatter, to pathological levels for quite a while. The phenomenon is global. The conventional explanation is too much for and not enough exercise, caloric surplus. This is not nonsensical. We know that caloric restriction leads to weigh loss. We can also see that various other approaches can result in weight loss. Carbohydrate restriction, for example. But, this doesn't give us a complete (or possibly even relevant) answer. This requires another 'why' and a 'why now.' All it takes is a small sustained caloric surplus over long periods to reach obesity. People have had access to these calories, in large populations or in pockets for a long time. There have been periods of regional caloric wealth and certainly periods of caloric wealth within subcultures/classes. If caloric surplus is the key idea, why do we have these caloric surpluses today. There were sedentary workers even in ancient times, certainly in the 20th century. Today's sedentary worker is fatter than yesteryear's. Today's carpenter is fatter than a carpenter in 1972. Why? A carpenter in 1972 had plenty of access to calories, similar physical lifestyle. IMO, this is an epidemic and we need an explanation that works at epidemic levels. We need to explain the change in populations weight, not differences in individual's weight. The answer to the first is probably different to the second. "Gut biome" may be an answer. Antibiotics. Parasites are another interesting possibility. In any case, I don't think it's coincidence that fad diet books and other pop science is so successful. We do not have an answer from science. I don't eves think the right question is usually asked. Why did we all get so fat?

philliphaydon 11y ago
We don't know? We do know and have known for a long time...
haywirez 11y ago
Didn't read the study, but part of the explanation could be that people spend less time outside and are generally in warmer environments. Omnipresent AC, different clothing, better insulation all means that the body burns less calories to keep itself warm.[0] "[...] in the U.K., average living room temperatures rose from 64.9F/18.3C in 1978 to 66.4F/19.1C in 2008 and bedroom temperatures increased from 59.36F/15.2C to 65.3F/18.5C."[1] [0][1] http://hypothermics.com/2011/02/ch-ch-changes/ http://hypothermics.com/2011/02/ch-ch-changes/

greatthanks 11y ago

The actual conclusion is hidden in the middle of the text: eat less meat First of all b/c its contribution to health is doubtable in general and at current times in particular.

Erwin 11y ago
That's not what I got out out if; they mentioned: avoid chemicals in food or packaging (i.e. eat organic - no antibiotic/hormone laden meat) - avoid artificial sweeteners - avoid antidepressant and unnecessary medication. Meat is fine, as long as you don't eat something too industrial.
- greatthanks 11y ago
  no - (red) meat is not fine: http://lmgtfy.com/?q=%22red+meat%22+site%3Anature.com http://lmgtfy.com/?q=%22red+meat%22+site%3Anature.com

cdnsteve 11y ago

Does this study take into account the exponential growth of portion size? Food portions in the USA are out of control, four times larger than the 1950's. http://www.huffingtonpost.com/2012/05/23/portion-sizes-infographic_n_1539804.html http://www.huffingtonpost.com/2012/05/23/portion-sizes-infog...

mattlutze 11y ago
"They found a very surprising correlation: A given person, in 2006, eating the same amount of calories, taking in the same quantities of macronutrients like protein and fat, and exercising the same amount as a person of the same age did in 1988 would have a BMI that was about 2.3 points higher. In other words, people today are about 10 percent heavier than people were in the 1980s, even if they follow the exact same diet and exercise plans." ^ The 3rd paragraph of the article.
- maxerickson 11y ago
  It can still be explained by people eating more. Take a 1980 individual that had been eating a bmi23 diet and start feeding them a bmi26 level of calories and they will probably gain weight. Take a 2015 individual's diet from bmi26 to bmi23 and they will probably lose weight.
  - cellshade 11y ago
    It says the same number of Calories in the post directly above.
    - maxerickson 11y ago
      Sure, but it isn't the same person. If my bmi23 diet is 2000 calories and I eat 2000 calories, I will probably have a bmi of 23. If my bmi23 diet is 1800 calories and I eat 2000 calories, I will probably have a higher bmi. I guess a clearer way to say what I am getting at is that bmi is descriptive, not predictive, so a shift in the bmi maintained by a given calorie intake could be explained by a shift in the habits of the population, so that the modern group achieves a given bmi at higher calorie intakes.

codexjourneys 11y ago

I suspect the answer has to do with the microbiome and its cumulative response over decades to antibiotics and tiny changes introduced in food (shifts in cooking oils, dairy product additives, even animal feed that then indirectly impacts our own microbiome when we eat meat or eggs or dairy, etc.). The problem is that studies on the microbiome tend to be limited and recent. Long-term studies are especially lacking. What we do have indicates the microbiome may be vital to not just digestion but also our immune system function, emotional well-being and weight. Probiotics might be helpful here, but in no way are we close to an exact science on the microbiome.

dr-g 11y ago

Is evolution via natural selection at play here? Or is the timespan too short for such a clear change to be seen?