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Scientist busts myths about how humans burn calories

• themodelplumber 5y ago
  > Exercise doesn’t help you burn more energy on average; active hunter-gatherers in Africa don’t expend more energy daily than sedentary office workers in Illinois; pregnant women don’t burn more calories per day than other adults, after adjusting for body mass. I love this intro. > His message that exercise won’t help you lose weight “lacks nuance,” says exercise physiologist John Thyfault of the University of Kansas Medical Center, who says it may nudge dieters into less healthy habits. This is funny to me because my own logs reflect this going back to about 2015. I can more easily drop 10, 20, or however many pounds when not exercising than I can when exercising. That was a really weird one because it opened up a bunch of other problems. One follow-on problem that came up quickly: How to develop skills requiring fitness during those times, or how to maintain endurance levels when you're intentionally lowering your exercise exposure so you can lose weight. That kind of situation is pretty interesting. > Azy, a 113-kilogram (249 lb.) adult male (orangutan), for example, burned 2050 kilocalories per day ... When adjusted for body mass, (humans) burn ... 60% more than orangutans Oh and > “She burned 40% more energy per minute in the math test and 30% in the interview,” Pontzer says. “Think about any other process that boosts your energy by about 40%.” This is really curious and fascinating stuff. Thanks op for posting. PS: > He calculates that the ceiling for an 85-kilogram man would be about 4650 calories per day. Combining this with the fact that Everest climbers are apparently eating 10K+ calories a day and then up to around 20K on summit day, I have to wonder how these facts jive...if they can really temporarily push the limit, for how long, etc.
  • ch4s3 5y ago
    > Combining this with the fact that Everest climbers are apparently eating 10K+ calories a day and then up to around 20K on summit day, I have to wonder how these facts jive... The estimate is probably off for extreme circumstances and those people probably aren’t fully digesting and using all of those calories. The accurate number would be interesting. I too have found that cardio isn’t very good for dropping weight, but packing on some muscle does a lot to shift body composition. Maintaining more lean mass simply requires more calories.
  • BeefWellington 5y ago
    > Combining this with the fact that Everest climbers are apparently eating 10K+ calories a day and then up to around 20K on summit day, I have to wonder how these facts jive...if they can really temporarily push the limit, for how long, etc. Yeah, I'm not convinced the article passes the smell test. Michael Phelps discussed his diet extensively, suggesting he ate 10k a day while training. Other athletes talk about similar meal sizes. This suggests that once they stop exercising (thus eventually losing lean muscle mass and requiring less calories) that they would not see a change in their weight, yet there are a lot of old fat athletes (possibly just of a certain generation) out there.
    • TameAntelope 5y ago
      They could just be shitting out the excess calories, and the article directly says, "Elite athletes can push the limits for several months, as the study of marathoners showed, but can’t sustain it indefinitely, Pontzer says."
  • voisin 5y ago
    > Combining this with the fact that Everest climbers are apparently eating 10K+ calories a day and then up to around 20K on summit day, I have to wonder how these facts jive...if they can really temporarily push the limit, for how long, etc. I think a lot of these stats are myths meant to accentuate the difficulty of the task. Pontzer’s book discusses Michael Phelps and the lack of an actual source to the rumours he was eating gargantuan amounts during training.
    • learc83 5y ago
      Michael Phelps directly says in one of his auto biographies that he was eating 8-10k calories a day. I don’t think you can call that a rumor. Of course he could be off a bit, but it seems unlikely that he’s off by a factor of 2. He lists the foods that he ate, and it definitely sounds like it was close to 10k calories. His coach also discussed his diet, and backs up his claims.
    • desmosxxx 5y ago
      So I'm not sure about everest climbers, 20k sounds pretty crazy. But I can speak first hand as a former athlete who has had access to NFL players and Olympians. 8-10k during peak active training happens all the time Long term average might be 4-5k. You have to remember that these people are often on PEDs that allow them to train all day. Shit I was a serious powerlifter back in the day and would routinely eat 6-7k calories (weighed) during 2adays depending on how my weight was fluctuating. Add some more height, PEDs, and cardio and I'm almost there. I think the difference between what is mentioned in the article is #1 obviously PEDs #2 body breakdown and recovery, which might be more in e.g. lifters and swimmers than long distance runners
    • suzzer99 5y ago
      I've read a decent number of books about climbing big peaks. In all of them they said they were so nauseous on summit day from being in the death zone, they could barely force down a protein bar.
    • darksaints 5y ago
      I believe him. As a nowhere-near-olympics division 1 swimmer, I had developed a major weight loss problem my freshman year. I actually was required to log my calories and meet with a sports nutritionist weekly. After 6000 calories a day, I was shoving so much food in my mouth, I felt like it wasn't possible to eat any more than I did. She prescribed Snickers bars as a way to top off my calories every day without contributing too much to feeling full. I was targeting 7000 calories a day, and I don't think I ever consistently reached that goal, but around that time my weight stabilized. There are a lot of people who maintain a high degree of fitness, and for them I can imagine 4000 calories is about right. But there are some types of training that are consistently pushing your physical limits. I don't have any sort of data to back this up, but it has long been my theory that the reason why elite athletes can burn so many calories is because they aren't actually burning them in the traditional sense of cells oxidizing chemical energy to create work...they've crossed over into the territory of muscle tissues being torn up and resynthesized so much that your body can no longer do so efficiently. As an analogy, typically in manufacturing there are always efficiencies that can be extracted. But in very mature industries where there aren't any easy efficiencies to eek out of the system, you have to start making tradeoffs. One common tradeoff is throughout vs yield. You can increase your throughout, but in order to do do so, you have to cut corners on processes and subsequently increase the total amount of waste in the process. And as a "maybe this is related" data point: 82% of marathon runners suffer from Acute Kidney Injury. Your kidneys have one job: waste disposal. It would be easy to infer that at the boundaries of human conditioning, the kidneys aren't up to the task of processing all of the waste that the body is producing. https://medicine.yale.edu/news-article/marathon-running-and-kidney-damage-what-runners-should-know/ https://medicine.yale.edu/news-article/marathon-running-and-...
  • libraryofbabel 5y ago
    > Combining this with the fact that Everest climbers are apparently eating 10K+ calories a day and then up to around 20K on summit day, I have to wonder how these facts jive...if they can really temporarily push the limit, for how long, etc. An interesting source here is the Fiennes and Stroud expedition to cross Antarctica in 1992. Stroud (a physician) actually tested how many calories they were burning each day using the doubly-labeled water method, and at one point (ascent to the polar plateau) it was up to 11k. So it is definitely possible to temporarily push the limit - as the article acknowledges - but these are exceptional circumstances.
    • PaulDavisThe1st 5y ago
      Another related extreme case was the first person to solo-ski to the north pole. They pre-loaded, mostly on olive oil, packing on tens of kg in body fat, all of which (and more) was gone by the time they were done. I don't recall the daily calorie expenditures but it was gigantic. They did this because there is some mechanical advantage carrying a good chunk of one's energy supply directly on your own bones rather than towing it in the sled.
      • libraryofbabel 5y ago
        Fiennes and Stroud lost about 25kg each crossing Antarctica; I don’t know if they pre-loaded beforehand (hopefully they did, losing that much!) but they certainly ran a deficit as a strategic trade-off against their sled weight. Hauling a kilo of fat on a sled is definitely less efficient than carrying it on your own body. Supposedly their calories during the expedition were primarily from butter, which they mixed into every food and even ate on its own. Apparently you get used to it.
  • JackMorgan 5y ago
    Some friends and I are currently doing a thru hike of the Appalachian Trail, and only ten days in the four of us clocked 7, 8, 10, and 17 pounds lost... But we're hiking 6+ hours a day with heavy packs. We've been eating easily ~3000kcal each daily. I think at the extreme edges, nutrition science is a lot less well understood. We were very surprised to see we'd lost anything at all, as we're stopping to eat 300 calories almost every waking hour.
    • PaulDavisThe1st 5y ago
      6hrs a day @ 3 mph = 18 miles per day, 100 calories per mile without packs = 1800 calories per day on top of basal metabolic needs. Given your user name, I'd guess that you're male, and given that you're hiking the AT and have already started, I'd also guess that you're younger rather than older, so I'd peg your basal metabolism at around 2200-2400 calories. Add in the packs and the hills, and it should be clear why you're losing weight.
    • colechristensen 5y ago
      A lot of an initial 10 pounds of weight loss can be dehydration and less food in the process of digestion.
      • JackMorgan 5y ago
        That's a good point.
    • 0x640x6D 5y ago
      Seems early to start the thru hike. How many people are on the trail?
      • JackMorgan 5y ago
        It's already at least 10 people at each shelter every night. There's ~60 people scheduled to leave on 2/22/22, and ~60 on 3/1/22. It's going to be real busy real soon, this year will be packed by March. We're taking it pretty slow and getting off trail whenever the weather turns sketchy (like last night possible thunderstorms). The real part we're concerned about is getting over the Smokies without getting stuck up there in the snow.
  • snowwrestler 5y ago
    Where are you getting those numbers for Everest climbers? I have a very hard time believing them. High altitude suppresses appetite in general and your body does not get enough oxygen to meaningfully process food above about 25,000 feet. Everest summit day via the South Col starts at about that altitude. Plus it’s freezing cold and everything takes forever to do. I don’t think there is much eating at all on Everest summit day, let alone 20,000 calories.
    • redisman 5y ago
      Napkin math: 20,000 calories is 36 Big Mac burgers In vegetable oil it would be about 4.8lbs of oil - that’s probably not at all plausible for digestion or bowel control
  • draw_down 5y ago
  • icedistilled 5y ago
    I'm baffled by the take away from the study. If a sedentary person and an athletic person burn about the same, doesn't that just mean the sedentary person's energy is being spent on maintaining and accumulating fat mass? But why is that waffled about instead of stated? Major Edit: more concise example >As the athletes’ ran more and more over weeks or months, their metabolic engines cut back elsewhere to make room for the extra exercise costs, Pontzer says. Conversely, if you’re a couch potato, you might still spend almost as many calories daily, leaving more energy for your body to spend on internal processes such as a stress response.
    • NautilusWave 5y ago
      If storing fat burned calories, it would make for a pretty poor way to store calories...
      • icedistilled 5y ago
        Cells don't live for free and fat is stored in cells. So yes storing fat burns calories, just far less than muscle. And that's just the direct expenditure. I see a few numbers thrown out for how many calories a pound of fat burns a day, but that direct burn is only one way additional fat would lead to energy use. A heavier person while less "active" will burn more during day to day due to carrying a heavier mass. I'm sure there's plenty more ways but I'm not going to go do a deep dive.
• renewiltord 5y ago
  Holy Jesus, that first chart tells a tale. The range of dense dots is from 60% to 130% almost throughout working life. Some of us are burning 2x what others are burning. Oh, man, dude. That's wicked variation after adjusting for non-fat mass.
  • bigodbiel 5y ago
    I always wonder how much of what we consume is actually absorbed, specially when factoring gut microbiome and non-soluble fibers.
    • toomuchtodo 5y ago
      This leads me to believe that obesity isn't an excess consumption of calories through food, but variation between people in how efficient or inefficient their digestive absorption is. Obese people don't need less food, they need a molecular knob to turn down the absorption of nutrients in their gut.
• dahart 5y ago
  > “You can’t exercise your way out of obesity,” […] “you can’t outrun a bad diet.” While this article is being a bit dramatic and possibly understating the impact of exercise slightly, I feel a little dumb that I didn’t know this earlier. It took me several decades too long to understand the obvious, that exercise is for building strength, and losing weight happens by eating less. I tried for way too many years to exercise my fat off, and it never really worked because I’d unconsciously eat to compensate. Once I tracked what I ate, exercise actually became more effective. A lot of people know this already, so it’s not busting everyone’s myths, but we also do have a strange narrative surrounding exercise and weight loss that I bought into. It makes me wonder if we’re physiologically wired to be allergic to the idea of less food, from an evolutionary perspective, because being hungry is literally risking death to our alligator brains.
  • louis___ 5y ago
    > we also do have a strange narrative surrounding exercise and weight loss that I bought into This narrative is pushed by the fast and highly-processed food industry. MacDonalds is sponsoring sport events with that very narrative : "morbidly-obese children of 8 should just do a bit more sport"
  • 2OEH8eoCRo0 5y ago
    Everybody is 100% responsible for what they eat. There is no excuse.
  • idontwantthis 5y ago
    > it never really worked because I’d unconsciously eat to compensate The wild thing is he’s saying that’s not true either. He’s saying you never burned the extra calories in the first place.
    • dpark 5y ago
      Not sure why you’re getting downvoted. That is literally the thesis here, that calorie expenditure is essentially decoupled from exercise.
• learc83 5y ago
  How do his results line up real world data like soldiers needing about 5k calories a day when active. Or athletes like Michael Phelps consuming 8k-10k calories a day while training?
  • abathur 5y ago
    I didn't read the article, but it may be relevant that (IIRC) swimmers lose a lot of these calories just to maintaining body temperature while in water for a significant fraction of each day (any activity that involves spending a lot of time in water may just be quantitatively abnormal?)
  • dugite-code 5y ago
    From my read of the article the data is heavily biased towards running as the exercise of choice, probably because measuring CO2 is easy and non-intrusive to do on a treadmill. They do mention utilizing doubly labeled water but don't say if they only used that for sedentary participants or measured a wider range of exercises. Given I have always heard/read how efficient humans are at running if they didn't account for the differing exercise methods the conclusion being offered in this article may be flawed.
    • kevin_thibedeau 5y ago
      Running isn't efficient at high speeds. The same with cycling. It's funny to see people buy a bike for exercise and then roll along at a crawl, expending less energy than walking.
      • PaulDavisThe1st 5y ago
        Cycling is roughly 5x more efficient than running/walking for similar effort. Thinking you will lose much weight by cycling is generally mistaken, unless you plan to cycle very long distances or are extremely obese already and do very little existing exercise (and this is discounting most of what TFA is saying too).
        • 5y ago
• voisin 5y ago
  I would highly encourage anyone to read Pontzer’s book, Burn. I just finished it and found it to be incredibly eye opening and well written. The TL;DR is that we need to think of calories like a relatively fixed budget rather than additive, and that the primary benefit of exercise is that it consumes that budget more than it expands it (hence not effective for weight loss), but by consuming that budget there is less budget to go around for unhealthy things like inflammation, excess hormone creation, etc (which is why exercise is so beneficial to health).
  • Terry_Roll 5y ago
    > but by consuming that budget there is less budget to go around for unhealthy things like inflammation, excess hormone creation, etc (which is why exercise is so beneficial to health). You dont understand inflammation, inflammation is like a nuclear bomb going off, however certain chemicals found in the diet will turn that nuclear bomb into an array of guided missiles. We are complex chemical reactions, eat the wrong stuff you get sick, eat the right stuff you get well, but you need to make the right chemical reactions take place and reduce the wrong chemical reactions. The problem with scientific study is they generally focus on what they can test directly or indirectly this is why we now see complete reversals in some medical thinking & theories. Sure exercise and other output will consume calories, but if you focus on just calories, you ignore the properties of the chemicals and ill health will occur.
    • voisin 5y ago
      He is referring to chronic low grade inflammation - not acute inflammation from specific chemicals. He cites studies. If you read them I would love to hear your take because you are correct - I am not an expert on inflammation!
      • Terry_Roll 5y ago
        What causes low grade inflammation? Generally Fat, what is fat and is anyone measuring what else is inside the lipid like fat soluble vitamins, hormones etc? > He calculates that the ceiling for an 85-kilogram man would be about 4650 calories per day. It still doesnt look at the what the short and long term effect is, he doesnt quantify it with this person can consume 4650cal but be dead next week does he? Its just a throw away statement, it means nothing and his ego/beliefs/followers are getting him into print before a larger audience. Because we are not able to quantify his statement properly, the media could be complicit in murder/manslaughter depending on what people know and remembered at the time. Our lifespans are limited by the traditional domesticated foods we eat, ie farm grown foods. However now that we are seening labgrown foods like fungi meat replacements and lab grown meats, the questions with those are do they contain enough of the chemicals to be good for health or not? You only need a few chemicals to grow cancer lines in a test tube for example, but cancer cells are not that functional in the scheme of things are they? They are just cells which have lost their normal function in the body. And I'm not qualified in anything, I cant even say if my GCSE are accurate because I never got my exam papers back to check my answers again the study books!
• aaronbrethorst 5y ago
  Pontzer was the guest on one of my favorite podcasts last summer. Great discussion with him: https://www.msnbc.com/msnbc-podcast/examining-energy-evolution-herman-pontzer-podcast-transcript-n1270125 https://www.msnbc.com/msnbc-podcast/examining-energy-evoluti...
• josefrichter 5y ago
  It’s sad that majority of people hit the gym or go for a run when they want to lose weight. Without diet it’s pointless. But what’s worse, diet change is also about finding a new balance that fits your body. If you start exercising at the same time, you are throwing your body drastically off current balance and it’s probably much harder to find a new one.
  • dpark 5y ago
    > If you start exercising at the same time, you are throwing your body drastically off current balance and it’s probably much harder to find a new one. This is for sure a [Citation Needed] claim. Exercise has been shown in numerous studies to be health protective and also to be muscle maintaining. I would love to know why you think exercising is not a net positive. I expect that greater than 99% off doctors, nutritionists, dieticians, and anyone else involved in human dietary health would agree that you should start exercising now if you are not already exercising, regardless of your diet (and absent specific contraindications).
    • josefrichter 5y ago
      The point is don’t try to change everything at once. I am not questioning health benefits of sports. But change of diet is a big change - not only biologically, but also mentally, logistically, practically, financially, etc. Change of exercise is equally massive change. It’s kinda logical that trying to juggle too many things at once is more likely to fail.
      • dpark 5y ago
        This is an entirely different thesis. You said that starting diet and exercise together is harder in terms of your body finding balance. Now you’re talking primarily about logistics and mental impact.
        • josefrichter 5y ago
          I wrote biologically and mentally as first two points, these concern your body. With diet you need to find what to eat, how much, how often, so that you’re not hungry, grumpy, tired, sick, etc. and still consistently lose weight. It’s gonna take a couple of weeks for your body to adjust. Exercise will also drastically affect your hunger, tiredness, etc. It’s gonna be harder to find new balance (or rather dysbalance with consistent weight loss) when you can’t really read which changes in your body are caused by diet and which by exercise. Higher chance of disappointment and quitting. I’d say just change diet, find what works for you consistently, add exercise only a few weeks later, tweak diet accordingly.
• dugite-code 5y ago
  > Exercise doesn’t help you burn more energy on average I have a problem with this hard statement based on the data because: > He realized he had to go back to basics, measuring the calories expended by humans and animals walking and running on treadmills. > He backed this up with a new analysis of data from another team’s study of sedentary women trained to run half marathons I've always heard that humans, due to our upright posture, are extremely efficient when it comes to walking and running and so if you want to increase you calories usage via exercise you should lift weights as we are much less efficient at this. I have also heard it will would increase your resting calorie usage as well due to repairing/reinforcing the muscle. I will note calorie management has always been heavily emphasized to me: "you can't out-run a fork" Perhaps that is wrong and a good data based analysis would disprove these common gym tropes I've heard but from my read of this article they only "bust" the morning breakfast channel myths of burning calories.
  • biophysboy 5y ago
    Maybe by "fixed budget", he actually means "fixed budget per kilogram".
  • dpark 5y ago
    Lifting weights is a poor way to burn calories. It’s a great way to build muscle and be healthier, but lifting weights is less efficient than aerobic exercise in terms of pure calorie burn. e.g. Moderate intensity aerobic exercise burns 200-300 calories in 30 minutes. Moderate intensity weightlifting is 90-130 in the same time. You need vigorous weightlifting to get up to 250 in 30 minutes. Even taking into consideration post-exercise burn, weight lifting will at best get you too the same efficiency as aerobic exercise. Example data from: https://www.medicalnewstoday.com/articles/323922#calculating-weightlifting-calories https://www.medicalnewstoday.com/articles/323922#calculating... Weightlifting is great but it’s not better for burning calories. It’s much better for retaining muscle while dieting, though.
    • dugite-code 5y ago
      I can't find the link but I remember reading an article about weight lifting raising the resting calorie use for quite some time after the exercise. Also as you say you retain more muscle, and that muscle requires calories at rest potentially altering the overall calculation. I still agree with the overall premise that fixing your diet is probably the most important aspect of weight loss though. May main take-away was from the article it read that they focused on running as the primarily measured exercise. So it might not provide the best full picture when looking at other exercise methods.
• nsxwolf 5y ago
  This is very depressing. I find it incredibly difficult to lose weight dieting. And now it's telling me I just wasted all this money on a treadmill (and the effort it took to get it down into the basement).
  • robotburrito 5y ago
    It is not a waste. The benefit of being active by using that treadmill is huge in many ways not limited to just weight loss.
  • jms703 5y ago
    You need strength and a sedentary lifestyle robs you of necessary strength. The treadmill is a great idea.
  • progre 5y ago
    You did not waste that money if it helps you exercise. The body needs to move to stay healthy. Never mind the weight, get your heart going a couple of times a week. When this is a habit, start to push a little. I think you will find that you feel a lot better after. I find that I eat a lot healther when I'm not stressed out. Exercise helps with that.
  • cf141q5325 5y ago
    If you have a low sustaining calorie level due to past diets, you might want to look up reverse dieting to make the whole thing easier. But even with a low level you shouldnt have much problems once you manage to track your input and arent dependent on junkfood. At the end of the day its an invisible red or green number. If the problem is with self control, remember that torturing yourself and viewing it as a battle can be counterproductive. If you just starve yourself you will likely bounce back directly afterwards. Its about making an actual change and normalizing your eating. For that i found it helpful to first stick to my sustaining calorie level, so planing what you eat at the level you dont gain or loose weight. You can then build on that structure with cutting out the addictive stuff, eating slower and figuring out being full vs not hungry. Personally i found a week of just boiled potatoes incredibly helpful (you will have to work really hard to gain weight with just plain potatoes) to kick the addictive stuff and break with bad habits. Its like with any other drug and abstinence wont kill you in this case. Dont beat yourself up, its one step at a time and with better planing you can make the steps a lot easier.
• digitcatphd 5y ago
  Has anyone considered that every N years a scientific “discovery”in a given field invalidates a previous one? Commonly in more theoretical sciences like nutritional science, psychology, and astrophysics? In other words, is anything really truly reliable in these domains?
  • purplepatrick 5y ago
    This is precisely how science works… Check out “Structure of Scientific Revolutions” by Thomas Kuhn when you get the chance.
  • inglor_cz 5y ago
    Nutritional science is in its own realm of unreliability, because it depends a lot on people self-reporting what they eat, over years and decades. Things like continuous glucose monitors are starting to proliferate, so the measurements are going to get better and more reliable, but it will still take a lot of time to come with some good long term studies where the self-reporting factor is no longer critical.
• hsbauauvhabzb 5y ago
  Is there a tldr on the research that doesn’t involve his life story or what his coworkers think of him?
  • Mathnerd314 5y ago
    You could read one of the book reviews: https://researchblog.duke.edu/2021/03/24/duke-researcher-busts-metabolism-myths-in-new-book/ https://researchblog.duke.edu/2021/03/24/duke-researcher-bus... Still not great as a tl;dr though. Maybe the book summary on Amazon: https://www.amazon.com/Burn-Research-Really-Calories-Healthy/dp/0525541527 https://www.amazon.com/Burn-Research-Really-Calories-Healthy...
• qaq 5y ago
  "You can’t exercise your way ..." You sure as hell can but it's a lot of effort. There was a decent stretch of time when I exercised for 2.5-3h per day 5-6 days per week while maintaining very unhealthy diet (we owned a pizza place that had Leffe on tap). Still managed to loose 20+ pounds in half a year.
• TheSpiceIsLife 5y ago
  On the matter of food and weight... What of the people who tend toward being thin or lithe? I'm 181cm and 68kg (5'11.26" and 150 pounds) at 40 years old. I can eat and quantity of any food in perpetuity and not gain weight. Although they doesn't mean I don't feel unwell if I were to, say, eat way too much of something. If I lift weights I gain a small amount of muscle mass, but not much. What's the theory(ies) of what is going on in the bodies of those like this?
  • xedrac 5y ago
    You're like my wife and her siblings. They can eat just about anything without putting on any significant weight. The running theory is that the food is not absorbed as efficiently, possibly due to it moving through the bowels too quickly, as some of them have IBS.
  • kart23 5y ago
    I thought I was like this. Track your calories. Eat 3000 calories a day, and a gram of protein per pound of bodyweight (150 grams for you). And I promise you'll gain weight, unless you have something wrong with your digestive system. It's actually pretty hard to eat like that consistently for many skinny people.
  • inglor_cz 5y ago
    My brother-in-law is even thinner than you. He can eat a lot of stuff. He also has Crohn's disease. I don't want to say that you have, too, but perhaps your digestive system isn't completely OK. That may include composition of your microbiome. Have you ever seen any change after taking probiotics?
• armchairhacker 5y ago
  I think of exercise and weight loss as completely separate. Almost everyone should exercise. Whether you're skinny, normal weight or overweight. Exercise makes you healthy. It also tends to make skinny people eat more and overweight people eat less, though not always. Form a workout plan with fixed amounts of exercise, like 30-90 minutes per day: any extra exercise isn't bad if you want it, but it doesn't really have any more benefits. If exercise helps you lose weight? Good. If not? Well it still has benefits. It's generally easier to lose weight through diet. If you really don't like exercise, you don't have to exercise much, and you can do workouts you like.
• _8j50 5y ago
  What is happening here? I've measured for a fact with myself where I eat more and workout more and lose weight.
• nathanaldensr 5y ago
  I wonder: Does this research mean that current TDEE calculators are incorrect? Or is the research more about how those numbers are correct?
  • AnEro 5y ago
    In my experience TDEE calculators are mostly best guesses and the more expensive the bestester the guess. This is mostly showing in various age ranges and pregnancy, you can expect variance compared to what is calculated. (not sure which method was used for this study as the calculated baseline for what was their expected TDEE) The use for this with TDEE is expect variance in age ranges in the graphic, ultimately there is no way to know until you test yourself with a diet for a few weeks. The biggest thing is showing how much mental stress plays into calorie burning, enough where an average western lifestyle can have the same calorie burned as a hunter gatherer.
• urthor 5y ago
  The thing is, exercise still reduces appetite. It raises the blood sugar levels as the body supplies the muscles with carbohydrates, and triggers a complementary response in appetite hormones. Finally, and most importantly: Exercise releases dopamine. Dieting is universally a mood killer, because kilo-joule deficit equals starvation. So whilst it does not directly impact weight loss. It still makes it (a bit) easier. Plus there are an enormous quantity of other factors in health that are impacted by exercise. Bodily strength is entirely responsible, for example, for stopping you getting a "bad back." The less strength you have in your back muscles, the more strain your vertebra and ligaments are under. Hence your body falls apart quickly and more easily. You definitely need both kilo-joule control and strengthening exercise if you want to keep your life on track.
  • happytoexplain 5y ago
    >exercise still reduces appetite This was one of the big surprises for me. When I'm exercising regularly, food tastes better, and yet I'm satisfied with less of it.
  • e40 5y ago
    Fasting isn’t a mood killer, it actually has the opposite effect. IF gives me an energy boost and associated euphoria.
    • cassandratt 5y ago
      While I don't experience any euphoria, I agree that intermittent fasting doesn't affect my mood negatively. After the first few weeks, you don't even think about it anymore. And being able to go out, eat a normal meal at a restaurant without worrying about math, or 'cheating on a diet', is pretty positive mentally when you can still fit into a size 6 dress.
    • cagmz 5y ago
      What is your IF schedule like? Can you expand on the euphoria?
      • 5y ago
• pengaru 5y ago
  I think it was someone in an HN comment who put it best: > exercise determines shape, diet determines size
  • pwned1 5y ago
    Another formulation that I like: Exercise to build muscle, eat to lose fat
• pleb_nz 5y ago
  For years I've heard Gym buffs say 'fitness starts in the gym, weightloss in the kitchen'
  • dehrmann 5y ago
    The version I've heard is simply "abs are made in the kitchen."
  • ehnto 5y ago
    Or the related quote, "Abs are made in the kitchen" (edit: oops someone beat me to that). Even someone who's never done a lick of physical training can have visible abs if their bodyfat % is low enough. Meanwhile some of the strongest people I know do not have visible abs.
• YaBomm 5y ago
• LaserToy 5y ago
  There is a new book about it called: Burn: New Research Blows the Lid Off How We Really Burn Calories, Lose Weight, and Stay Healthy The only way is to eat less.and to eat less we need to eat less manufactured food designed to be addictive
• gmiller123456 5y ago
  Is there a browser extension that removes all of the fluff and narration from what attempts to be a scientific article?
• EGreg 5y ago
  OK, so then, what does make people lose weight? And all those pounds come off? How do you help someone who is mildly obese go to having a bikini body? I read you lose calories by breathing heavily, as the CO2 leaves your body, etc. In my opinion, it's not about aerobics, but building muscle mass. Women who pack on muscle burn more calories at rest than women who don't. They may weigh the same but the fat is replaced by muscle. (Women need fat, though, so too much of this can be bad.)
• zenlf 5y ago
  This is interesting. However I would love to learn more about the “doubly labeled water method”. For example, how accurate is the test result? What’s the individual variance? Do animals and humans react the same way to it? It’s important because all the findings seem to be based on it, but the specifics are not discussed.
  • usaar333 5y ago
    I got curious and did a bunch of research. It relies on the fact that carbon dioxide is transmitted from tissues to lungs in blood as carbonic acid. The carbonic acid is formed by water and carbon dioxide. It seems extremely accurate as long as you believe the distribution of labeled water equalizes in the body. You can readily see exactly how much labeled oxygen was lost via CO2 (via the carbonic acid reaction). As long as metabolism and blood transport works the same in all animals, seems reliable.
• gunshai 5y ago
  When I want to lose weight I do this one simple thing ... I stop eating as much. Fasting really isn't all that difficult once you train your brain around it. You simply can't gain weight if you are consuming less. You don't need a triple PhD to understand the law of conservation of mass. If you want to read something fairly extreme I suggest the following. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2495396/ Now this isn't a guide on how to lose weight, but it should give everyone some insight into what the human metabolism is capable of.
• vee2xx 5y ago
  We should be glad the human body is this efficient and that we can reduce the resources we consume instead of finding ways to pander to our gluttony.
• tonymet 5y ago
  it’s not complicated : eat less walk more . increase both until you see a change . and stop the obsession with food it’s not healthy no phD needed
  • timbit42 5y ago
    Hunger complicates it.
• icedistilled 5y ago
  Since the article is comparing non-fat mass is this saying that someone with 60kg of non-fat mass will burn the same amount of calories if 1. their overall mass is 75 kg and they're athletic or 2. have more fat mass being 85 kg overall and non-athletic? I'm not sure what i'm missing but that isn't shocking or surprising. I feel like someone's trying to pull a fast one here. "female farmers in western Africa used the same amount of energy daily when adjusted for fat-free body mass as women in Chicago —about 2400 kilocalories for a 75-kilogram woman. "
• xwdv 5y ago
  But will keeping a fast metabolism due to exercise ultimately shorten our lifespan?
• 14 5y ago
  I came up with a diet to lose weight. I was approaching 200lbs and wanted to get it under control so made a simple diet that helped me lose 50lbs. I call it the half and half. You take your meal and plate it. Then take a second plate and split everything exactly down the middle. Eat your first plate and then you wait half an hour. If after half hour you want to eat again you can go back to your second plate. What ends up happening is some times you would go back for more but other times you would get busy. Or just not feel hungry. It wasn't long before my stomach started to shrink and I would eat smaller and smaller amounts of food. This worked incredibly well. I could eat anything type of food I wanted just needed to wait half hour before going to my other half of my food. I eventually stopped splitting my plates and just made very small plates because I realized I would be full off a little amount. The only other rule I followed was never finish food once I feel full. That last bite of a burger just toss it if you feel full.
  • ehnto 5y ago
    You might have heard of it by now but I suspect you're exploiting the mechanism that delays the feeling of satiation for roughly 20 minutes after eating. Many people can eat a seemingly unlimited amount of food so long as they do it quickly. I think your method is cool because it tricks both the hungry and the logical part of your brain into thinking it can totally have all the food so long as it waits, but by the time 20 minutes is up, the satiation chemicals have found their way to your brain and it's no longer hungry.
    • 14 5y ago
      Thank you. A lot of people just shrug it off when I say I have a diet. They look at me and say but you are skinny like you ever needed to diet. Well I really was 50lbs heavier at one point and that is a lot. I think you nailed on the explanation as to why it happens as well. When you know you can go back for more it’s not some painful I need to starve feeling you can reason with yourself and say okay I had my first plate it’s not going to be bad to wait half an hour where as if you had to wait say several hours you may be tempted to have just a bit more because of hunger pains. Also not being restricted to certain foods makes it easier as well because who really wants to make a big change to the foods they already eat. Well thank you for commenting.
• locallost 5y ago
  I was wondering about this recently. My fitness tracker estimates seemed just a bit high for months now, that you'd think those extra burned calories (500-1000 per day) would result in less weight. But no, the only weight I lost was in the time periods I was actively skipping meals or snacks.
• Helmut10001 5y ago
  If your only goal is weightloss, then yes - but just weighting 50kg doesn't mean it is healthy. You can have fat at 50kg, just in the wrong places. Activity provides many positive effects, such as better immune system, better distribution of nutrients in the body etc. Trying to loose just weight without a training plan is not productive.
• allisdust 5y ago
  Can't they get to the science part without dramatising the scientist. It's a long slog with tidbits thrown here and there. I hate articles like this that assume that reader is up for biography instead of the core subject. We get it. Everyone's story is unique. No need to hash all that uniqueness in every article about their work.
• ChicagoDave 5y ago
  This is all very depressing. I'm one of those people with a limited menu (possibly an eating disorder) of things I will eat. I don't like complex dishes (anything eastern), seafood, vegetables, and fruits only in smoothies. I definitely ingest too much sugar and drink diet Coke. For myself, I think exercising somehow makes me eat better. It's just a naturally occurring thing that if I start Couch to 5k, after a couple of weeks I stop eating greasy food, chips, pizza, and I eat salads and all around healthier and smaller portions. So I guess when I lost weight in the past, it was because of the effects of exercising. Not the exercise itself. Wish I could solve the eating problems, but I'm 58. I get severe anxiety if anyone tries to get me to eat things I don't like. I've skipped dinner parties and other events if I think the food won't be what I like.
• ericmcer 5y ago
  I feel like this is already known? I watched some anime Netflix years ago where the main character played a board game. Eating candy to account for the energy expenditure of the mentally taxing game was in the script. I read an article about Magnus Carlsen exercising and eating a strict diet so he could cope with the energy expenditure of high level chess for long periods. It's weird to see it now framed as like a revolution that making this girl do rapid math problems increased her calorie expenditure.
  • Terr_ 5y ago
    > Eating candy to account for the energy expenditure of the mentally taxing game That reminds me of someone who made a fanny-pack that tracks your walk/run progress and dispenses M&Ms. https://hackaday.com/2021/07/30/step-n-snack-fanny-pack-motivates-with-mms/ https://hackaday.com/2021/07/30/step-n-snack-fanny-pack-moti...
  • csee 5y ago
    I don't know if it's the mental difficulty or the stress associated with the task that is causing the energy to be burnt. I'd like some clarity on that if anyone has studies. > I feel like this is already known? I'm not sure about that. I heard a lot of people say "exercise doesn't help you lose weight because you eat more", not "exercise doesn't help you lose weight, because it doesn't really burn calories.".
• NautilusWave 5y ago
  I found the unquestioned valuing of weight-loss throughout the article tiresome. It also seemed to be entirely besides the point; not once did it mention any research Pontzer had done on the topic. My frustration with the article was only compounded by the repeated use of the term du jour, "inflammation". How he confidently states that exercise can reduce this nebulous phenomenon, basically without any evidence, is incredibly dangerous.
• ravenstine 5y ago
  Although it may seem surprising to some that humans put on more fat than their fellow apes, this is at least somewhat predictable when you look at other ways in which humans are different from other apes. Putting aside our intellect, we our developing towards having little to no fur came with the benefit of being able to sweat, which means we could track animals further than they could persist. It allowed us to effectively outrun, or outwalk, herds of animals. That comes with a tradeoff, which is the lack of fur means not being able to retain as much heat in the cold. Being able to store more fat is the obvious alternative.
• hamilyon2 5y ago
  Why does article call hydrogen and oxygen isotopes harmless to human body? Is there a sound science behind the claim?
• deepnotderp 5y ago
  The conclusion is almost certainly wrong: 1. From a simple sniff test, if this were true, then athletes wouldn't need a lot of calories. This obviously isn't true, eg Phelps eats 8-11K calories a day. I personally eat around 3.5K calories a day. If exercise didn't impact caloric burn I assure you I'd be a lot fatter... 2. The only plausible mechanisms for why exercise wouldn't result in more overall caloric burn is that less energy is expended in non exercising states, eg the body is trying to conserve energy and either reduces metabolism or reduces fidgeting, walking, etc. This often happens to people trying extreme calorie loss diets. The implication of this is that somehow the sedentary lifestyle of your average couch potato is the "normal" lifestyle for a body, and the lifestyle of a hunter gatherer is "overactive", and their bodies are chronically tired and trying to reduce their metabolisms. That... seems quite unlikely. 3. Finally, this blog post dives into some methodological issues: https://darrendahly.github.io/post/2012-08-31-hunter-gatherer/ https://darrendahly.github.io/post/2012-08-31-hunter-gathere... EDIT: Increased metabolism due to muscle mass is not as big an effect as you’d think: https://www.unm.edu/~lkravitz/Article%20folder/metabolismcontroversy.html https://www.unm.edu/~lkravitz/Article%20folder/metabolismcon...
  • guerrilla 5y ago
    > If exercise didn't impact caloric burn I assure you I'd be a lot fatter... Simply having more muscle mass can burn calories too. Most people don't spend most of their time training either, so comparing to elite athletes is fairly irrelevant.
    • deepnotderp 5y ago
      True, but the effect is not as big as you would think, see eg: https://www.unm.edu/~lkravitz/Article%20folder/metabolismcontroversy.html https://www.unm.edu/~lkravitz/Article%20folder/metabolismcon...
  • ckastner 5y ago
    > From a simple sniff test, if this were true, then athletes wouldn't need a lot of calories. That was my first thought as well. It's even more evident with certain types of sports. Take cycling for example. Lifting mass up a mountain is going to take quite a bit of energy; maintaining a constant speed in the face of wind resistance will take energy. That energy has to come from somewhere.
• Janiya 5y ago
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• xurukefi 5y ago
  "You can’t outrun a bad diet" seems to be the party line among fitness people these days. Anecdotally speaking that's not really true for a lot of people. I run > 100km/week pretty much all year round (most of it on extremely hillly trails) and despite my bad diet consisting mainly of pancakes, white bread, nutella, pizza, fries and burgers, I am not overweight with 78kg at 190cm. Before I picked up running I was moderately overweight. If I can't run for a prolonged period of time, then I start gaining weight again. I've met plenty of people who run similar mileage and many of them also have pretty bad dietary habits but none of them are oeverweight. Note that I'm not saying that this is healthy (it clearly isn't). However, I still think that there is a lot of truth to the "you can't outrun a bad diet" statement. A lot of people who occasionally go for a run are likely to overestimate their energy expenditure and feel like they have to eat a cow to compensate. I think, however, that the statement becomes less and less true the more excessive the exercise gets. If you burn thousands of calories day in day out with exercise it seems to become harder to overcompensate this every time with excess food intake. I think the bigger issue with exercise is a mental one. Weight loss seems to be a pretty bad motivation for exercising. Most people I know who picked up running for the sole purpose of losing weight eventually gave up or they are stuck with their 5km weekend park run, which, of course, is rather pointless for their objective. 100% of the avid runners I know (including myself) don't care about their weight. I could probably lose more weight (or improve my long term health) if I changed my diet, but it's simply something that I'm not interested in. I run because it's fun and a somewhat low body weight seems to be a by-product of that.
  • deleted 5y ago
    [deleted]
  • edanm 5y ago
    I think I agree with your general point, and specifically agree that that statement is targeted as "mainstream advice", and might not be literally true. However, one point of disagreement: > I run > 100km/week pretty much all year round (most of it on extremely hillly trails) and despite my bad diet consisting mainly of pancakes, white bread, nutella, pizza, fries and burgers, I am not overweight with 78kg at 190cm. That is not necessarily a "bad diet" for weight loss purposes. It's an unhealthy diet, but as long as you're not eating too much of all those foods, it won't make you gain weight. It's only bad because most people who are eating these kinds of foods will be eating too much of them (because they are much less filling for the amount of calories that they contain).
• Bancakes 5y ago
  Man people will invent anything to avoid eating less and exercising more. Sorry professor but the human body obeys the laws of physics. Calories in, calories out.
• 8bitsrule 5y ago
  I've a question I've never seen addressed. It's likely that some of what you consume is actually utilized ... and that some, if it's not needed, is just 'ignored' (excreted). Oxygen needed? Very little. Also some people can eat and eat, whatever they want, and not gain a lot of weight. Genetics has to be part of it.
• rdiddly 5y ago
  Last thing I saw was "The son of two high school English teachers, Pontzer grew up on 40 hectares of woods in the Appalachian bla bla bla..." You know that sentence. So many articles have that sentence. The one where it veers off course to talk about the (usually uninteresting) person who found the thing the article is ostensibly and nominally about. Am I alone in being perfectly happy reading about science for the duration of an article, and not particularly caring about the scientist and what breed of dog he has etc.?
  • tpoacher 5y ago
    I had a very similar outburst recently :p https://news.ycombinator.com/item?id=30344510 https://news.ycombinator.com/item?id=30344510
  • hwers 5y ago
    This is a reason we shouldn't feel ashamed about developing a habit of skimming. In many cases it's simply a proper adaption to an incredibly low signal to noise ratio in most articles you're exposed to on the internet.
    • gima 5y ago
      Props to this. I have developed a habit of skipping to the end of the whole page, and reading towards the beginning, paragraph-by-paragraph. Works..sometimes :D
  • periheli0n 5y ago
    You could read his papers if you're only interested in the science?
  • joeld42 5y ago
    There are different kinds of articles out there. Some are about getting the information across, some give the context and the story behind it. Some aren't even about the science at all. I wouldn't compare John McPhee to a Geology textbook. And I wouldn't say it's correct that this article was "ostensibly and nominally" about just calories. The headline is "Scientists bust myths about calories". It's about the scientists as much as it is about the calories. Anyways, that's all to say, I do enjoy articles like this that give context and explain not just the research but the people behind it. Let people enjoy things.
• kohlerm 5y ago
  Of fine running alone might not help you to lose weight. Also there might be a feedback loop to not eat too much crap for a serious runner. E.g. running with less weight is just more fun :-) But does that mean other activities where you gain muscle mass would not help to keep your weight in an acceptable range? I could be very well the case that burn more energy because you have more muscles.
• radu_floricica 5y ago
  > when adjusted for nonfat body mass > when adjusted for fat-free body mass The article is not cheating, but it's not underlining this bit which is essential. It's talking about aerobic exercise, which means "trying to run your way to being thin doesn't work". Which may be news for some people on HN from what I see, but is far from being new or controversial. On the other hand, building muscle gives you a perpetual "eat more" card. It permanently increases your fat free mass, and thus your TEE. I haven't heard anything about a similar increase in appetite - if anything, bodybuilders struggle to eat enough calories. So, boys and girls, definitely hit the gym. Just stay away from the stepper and pick up some weights. Also don't forget protein intake when you do that.
• tommiegannert 5y ago
  I wonder if the body is constantly hitting the upper limit of something, like temperature or kidney flow. If the parts of the human body are very elastic in their energy use, then this means we're overall maximizing energy expenditure. I guess that could make sense while there's an excess of available energy in the guts, which would otherwise go to waste.
• choeger 5y ago
  What the article doesn't mention is that the "extra reserves" in the body, i.e., the calories that are currently used and are not burnt when exercising, must be a constant (the body can only skip burning calories that it gets) whereas exercise can be scaled. Say you are overweight on a 3000kcal diet and start exercising. It is physically impossible to not lose weight if you exercise for more than 3000kcal. You might not lose weight if you exercise a more modest 1000kcal or even just 500 - but the statement that you cannot outrun your diet is trivially false. It might just be much harder than one might naively assume.
• Oras 5y ago
  I couldn't finish the article due to the excessive fluff! Reading the comments, I'm glad I wasn't the only one. How about summarizing the main points at the top for those who are interested in real information instead of the height and weight of the scientist?
• sfifs 5y ago
  Please is there a summary of the findings anywhere? I'm beginning to lose patience with these pieces that mix narrative, character profiles and actual results.
• hdjjhhvvhga 5y ago
  Can someone tldr? I read several paragraphs and know so much about this scientist but so little about the myths he's supposed to bust.
• thedogeye 5y ago
  Why do swimmers eat 8 meals a day without gaining weight ?
• caffeine 5y ago
  This article really needs a TLDR. Reading it in between the cookies notice, the subscribe modal, and trying to slog through a detailed history of everything this guy has done since he was 10… Has anyone managed to get through this who could post here: what is the conclusion about humans burning calories?
• erfgh 5y ago
  I don't even know if counting calories works. I feel that when I'm in a calorie deficit my body just gets colder which means it is burning less calories which in turn means I might not be losing any weight.
• dschuetz 5y ago
  The article is very interesting to read, except the part where his personal life is spotlit. Finally something more nuanced research done on this. In my lifetime I was told pretty contradictory views on how fat metabolism works and what exactly 'exercise' means. You cannot eat the same and hope to loose weight just by exercising more. You would be burning 'cheap calories' first, but the fat tissue stays untouched, as it is more expensive to burn. Changing or regulating diet correctly reduces the intake of those cheap calories, most of them are liquid or in processed food, like beer, alcohol in general, processed sugar, some dairy products, and so on. Exercise and the right diet complement each other, and according to this guy it makes only sense: exercise forces the metabolism to burn calories for physical activity instead of stress response, and that means lower levels of stress hormones. The correct diet forces the metabolism to burn glucose stored in the muscle tissue first, and then slowly starts using the energy from the regions where the digestive tract is. So after decades, the right balance between diet and exercise is still the better way to loose weight and be healthier, however this guy says that body burns calories differently than assumed, each activity burns calories, even if it's sitting on a couch all day.
• dandare 5y ago
  > Then Pontzer asks a set of questions designed to boost a student’s stress levels: What’s her dream job, and what exactly is she going to do after graduation? or > launches into a time-honored method to boost her blood pressure: He gives her an oral math test. Anybody else noticed this gem? I would like to see a list of topics like this - for just to be a better conversationalist. (It reminds me of how people who don't have children (or don't understand children) when meeting a child they don't know often ask it the only thing they vaguely know about every's child life - how is school?)
• tpoacher 5y ago
  So the main argument in the article is the claim that your total energy expenditure is more or less constant, and independent of "exercise". In the sense that if you spend 500kcal on running, your body will "not do" something else it would have done otherwise (e.g. stress about stuff) that would have cost 500kcals. In other words it challenges the idea that if you run today and not tomorrow, your TEE on day 1 will be 500kcal higher than day 2. The claim is that TEE on both days will be the same. Ok, that is an interesting finding. But this sounds very specific to aerobic exercise. The article then mentions how they monitored an active indigenous population, and were "surprised" to find out that "when controlled for non-fat body mass this active population had the same TEE as western sedentary populations" (emphasis mine). Why is this at all surprising. We've known for ages that muscle increase leads to a basal metabolic rate increase. The article tries hard to give a visual impression that two similarly rotund people (one from fat and one from muscle) would have an equal TEE, but if you dig into the claim, it's exactly the opposite. In order to get that non-fat body mass difference, you need to exercise. Its just that this needs to be anaerobic rather than aerobic. We also know that obese people have higher BMRs than their thinner counterparts. Now if the claim in this article is true, then it would imply that the increase in BMR in obese people is exclusively due to a parallel increase in muscle. But we know that muscle increases with obesity. So again, not very surprising. So, the claim "exercise doesnt work" indeed lacks nuance. Particularly in not addressing aerobic vs anaerobic exercise.
  • xurukefi 5y ago
    > So the main argument in the article is the claim that your total energy expenditure is more or less constant, and independent of "exercise". In the sense that if you spend 500kcal on running, your body will "not do" something else it would have done otherwise (e.g. stress about stuff) that would have cost 500kcals. > In other words it challenges the idea that if you run today and not tomorrow, your TEE on day 1 will be 500kcal higher than day 2. The claim is that TEE on both days will be the same. That's wild. Running a marathon will easily burn north of 2000kcals. That's a lot of "something else" the body will have to "not do" to compensate for.
• mjsweet 5y ago
  I read somewhere that the only way we lose weight is by exhaling.
• drakonka 5y ago
  I wonder if this could partly explain why some people gain muscle easily without eating more when lifting regularly. Common wisdom says you have to eat more to make up for the extra energy expenditure, or otherwise your muscle growth will be limited. But I'm just not that hungry. Yet not purposefully supplementing with more food during training regimens never seemed to hinder my muscle growth. Then again, I don't know that. Maybe I would've gained even _more_ muscle if I'd been eating more. Anecdotally, it just seemed like muscle has come on pretty easily regardless of how much I eat. Could the body simply be redirecting more of my calories to growing muscle during these periods while keeping the total expenditure the same?
• jokoon 5y ago
  It's really annoying that when there isn't good science on a subject, a lot of people will expose their own certainties that they think makes sense. Metabolism, the gut flora, those are pretty complex processes. Bacterial imbalance in the gut is a good trail to follow. Of course ceasing food intake for 1 year would make anybody lose weight, but you can't tell everyone to run 50 miles a week to lose weight. There are obviously other root causes for obesity.
• Someone 5y ago
  FTA: Pontzer’s findings have a discouraging implication for people wanting to lose weight. “You can’t exercise your way out of obesity,” says evolutionary physiologist John Speakman of the Chinese Academy of Sciences. “It’s one of those zombie ideas that refuses to die.” I think that’s true, but have one remark: those studies all scale by fat-free body mass. Exercise can increase that, so exercise that grows your muscles, combined with maintaining the same diet should decrease the derivative of weight over time. That doesn’t imply you’ll lose weight; if you were gaining weight fast, chances are it will just make you gain weight a bit slower. Even if you’ll lose weight, chances are it will be too slowly to motivate you to continue. Also note that most obese people already have strong muscles (if you weigh 200kg and can walk, you’re carrying around 100kg or so) and, because of their weight, are injury prone. Becoming stronger through exercise may be very hard for them.
• deleted 5y ago
  [deleted]
• pwrrr 5y ago
  "You can't burn calories. Calories is a measure of heat. You can't burn heat." - Bart Kay CICO, Calories in/Calories out also doesn't work like that in the human body, because the human body is not a closed system. https://www.youtube.com/watch?v=crA0MLKleBQ https://www.youtube.com/watch?v=crA0MLKleBQ
  • Aachen 5y ago
    In that case, explain to me how my house gets warm from burning caloric gas ... calories are obviously the measure of how much heat you get from burning something, not the heat itself that you're "burning"
    • 0xcde4c3db 5y ago
      > calories are obviously the measure of how much heat you get from burning something, not the heat itself that you're "burning" I think that's exactly the point: calories can only measure how much we're burning, but what we're burning matters just as much, if not more. If your gas service was cut off, you would (I hope) not pump crude oil into your furnace instead. It might be accurate (as far as it goes) to say that a furnace is a machine for turning hydrocarbon fluids into heat, but you probably respect your furnace and its requirements too much to do something like that. Most people, including too many exercise and nutrition "experts", are all too happy to make oversimplifications nearly as silly when thinking about our own bodies.
• Xcelerate 5y ago
  The article seems to miss what is (at least to me) the most interesting follow-up question: if exercise doesn’t cause a person to burn significantly more Calories throughout the day to induce weight loss, then what does? I’m somewhat hard-pressed to believe the answer is diet alone. Anecdotally, when I was running 100 miles per week in college for cross country, I ate three or four giant meals per day and maintained a very low weight. Ten years later, I have an injury that makes most types of exercise difficult, and I’ve observed that I really can’t eat more than one meal per day (dinner), otherwise my weight starts to creep up. I find it odd that Calories are used in relation to weight gain, because (kilo)calories are a unit of energy, and excess weight is due to excess fat. Is there a simple linear relationship between the extractable energy content in food (as determined by the Atwater system) and the conversion of food components into fat by the digestive system? I find that hard to believe. Shouldn’t we be using a mass balance rather than an energy balance? If you could observe digestion at the atomic level, you would simply quantify which atoms from food end up in fat stores and which leave the body via other processes. Presumably, these atoms could then be bucketed into source categories (e.g. certain types of proteins or carbohydrates). I wouldn’t be surprised if exercise somehow alters the fat accumulation process even if it doesn’t significantly affect human metabolism.
  • akeck 5y ago
    If I recall correctly, capital "C" Calorie, used in nutrition, is another term for kilocalorie. Lowercase "c" calorie is the SI unit. 1 kcal/Calorie is 1000 calories.
    • Xcelerate 5y ago
      That’s correct. I used a lowercase “c” for (kilo)calorie to highlight that explicitly, but capital “C” elsewhere.
  • csee 5y ago
    The article proposes stress and inflammation.
    • 5y ago
• xweber 5y ago
  There's this great book 'Why calories don't count' by Dr Giles Yeo. It discusses how the human body processes food and extracts energy from it - and how current calorie labels on food items don't account for this process. Highly recommended.
• akeck 5y ago
  I lose weight when I exercise, but I don't burn nearly enough calories to account for the weight lost. My guess is that the exercise reduces stress which inhibits stress eating, so my intake drops.
• gverrilla 5y ago
  seo.org
• bluecalm 5y ago
  I would like to see some answers on this one. First, why are we adjusting for lean body mass? I mean if you're 120kg with 50kg of extra fat you will obviously burn more calories by carrying that around. Someone who doesn't have additional 50kg of fat will need to exercise to burn the same amount of calories. It's well known in fitness circles for years now. It would be surprising if lean sedentary people burnt as many calories as active ones. The limit of 4650kcal per day doesn't sound right. A lot of endurance athletes, even amateurs, burn more than that. How much you can digest is limited (common wisdom is 60-90g of carbs per hour when exercising which is 240-360 calories). Still there are also glycogen stores for additional 1500-2000 kcal as well as your fat stores which are heavily in use during long lasting endurance effort. I assume the limit is meant for long term which would make more sense. The fact about ultra marathoners who burnt 6200 kcal at the beginning of the race but only 4900 at the end is interesting. Assuming they weigh say 60kg then it takes around 2500kcal to run a marathon. There is a lot of other stuff going on if they burnt 6200 per day. It would be interesting to see if there aren't other information that explains the difference (like hills for example).
• dmitrij 5y ago
  It's nice when science confirms personal experience. Early 2020 I started to change my life. Exercise, healthier food, weight control. My conclusions: I got stronger, had less back pain and less fat, felt calmer. Weight went down significantly. After restaurants opened, I started again eating more fat and drinking more wine while continuing exercising and eating healthy at home. Strength and calm stayed, weight got up. My conclusion: exercise is good in any aspect, but weight control also needs control of calories intake.
• iguana_lawyer 5y ago
  “Pontzer is happy to expound on weight loss on The Dr. Oz Show…” And I’m happy to stop reading the article right here and ignore everything this quack has to say.
• unnouinceput 5y ago
  Quote: <<“She burned 40% more energy per minute in the math test and 30% in the interview,” Pontzer says. “Think about any other process that boosts your energy by about 40%.”>> So that's why I became fat as a pig since I started freelancing more than 14 years ago. Because I'm no longer stressed in corporation bullshit politics and actually enjoy working with my clients. Stress free life means less energy used, means eating will get more food transformed into fat. Also probably why I didn't exceeded a certain number, I am at current weight for like a decade now, and I still eat like a pig but I don't gain weight anymore. Seems is time to go run for politics, increase the stress in my life /s.
• jimmyvalmer 5y ago
  tldr tl;dr Our bodies self-correct to maintain a constant calorie expenditure. Marathoners and lean-mean bush people were found to burn as many calories daily as a middle aged woman from Chicago. Takeaway: eat less if you want to lose weight.
• lngnmn2 5y ago
  Wow, this is a milestone indeed. Abstract bullshit considered as an overturn of a simple experimental evidence even a freshman could set up and measure.
• wildmanx 5y ago
  Irony. A linked article describing a scientist trying to rigorously find out how weight changes and energy expenditure and diet are connected, revealing the little we do know and the vast sea of what we do not know. The discussion here: full of anecdotes and bro science berating one another "that's not how it works, it works like this", "I personally do this-and-that", "you just have to x-y-z, it's that simple".
  • tom-thistime 5y ago
    Yes. And no. Bro science is more or less useless. But the article isn't super useful either. Calories burned are "adjusted for nonfat body mass." Adjusted how? Fat stores energy. Food adds energy. Exercise uses energy. Those aren't "myths." The article (not talking about the scientist) is very difficult to understand, but it seems to come down on the "myth" side of that dilemma. Mostly. Kind of.
    • koheripbal 5y ago
      When you do the math, your body turns out to be extremely efficient. Two full hours of very hard exercise burns the equivalent of one average sized lunch meal. Skipping meals/cutting calories is, by far, the easiest way to lose weight.
      • tom-thistime 5y ago
        Let's get specific. Maybe your suggestion might be a cataclysmic -1000 calories per day, either by (a) skipping a large lunch completely and not changing exercise, or (b) by doing those two hours of hard exercise and not changing diet. That person will tend to lose around two pounds a week either way over the long term. (Of course I don't really know what numbers you have in mind.) But losing two pounds a week is insane. So let's look at safer, more normal behavior. Call it -300 calories per day: either cutting diet by a medium order of fries each day (and keeping exercise fixed) or doing 40 minutes of moderate exercise (and keeping diet fixed). Then the person will tend to lose a pound about every 12 days over the long term. That is still rapid weight loss either way. If the same person starts riding a bike 40 minutes a day but doesn't count calories, the results could be anything. They could easily put on weight. Who knows?
• projektfu 5y ago
  Some of the papers have strange errors that suprise me that they passed peer review. For example, "Extreme events reveal an alimentary limit on sustained maximal human energy expenditure" by Thurber, others, and Pontzer has a figure labeled "Fig. 3 Maximal Energy Intake". First, it appears that one of the charts is labeled incorrectly. I assume it is the first one, and they swapped "Overfeeding" with "Endurance". Second, it seems that taking the disparate types of "event" and putting them together on the Energy Intake graph causes them to have a flat slope, whereas the slope would be somewhat positive for the subgroups. This was like one of the first few things I looked at in this body of research, I wasn't combing through everything to find an error. But it's strange. Finding an error quickly is a red flag to me. Overall the study I'm looking at is interesting. I'm not sure they adequately demonstrated the finding of a caloric intake limit of 2.5x BMR but there appears to be a definite negative correlation of duration of sustained activity and energy expenditure (or metabolic scope, a multiple of basal metabolic rate). The numbers are very tightly clustered around the trendline, which is kind of odd, given how widely the numbers vary in other graphs. So either this is a very close correlation or something is strange with the data. Glancing through the papers in PubMed, I think that the implications in the article are way stronger than the papers support. One paper said that perhaps 25% of the calories expended in exercise are borrowed from a reduction in BMR. The article made it seem like they were completely offset. The article referenced above apparently used two very different groups (overfeeding and endurance competition), and used the first to study the limit of energy intake and the second to study the long-term limit of energy expenditure, but people are making claims about energy intake in endurance athletes. Maybe when you're working hard, the gut is able to adapt and pull in more calories. Perhaps there is a limit to how much the gut is willing to accept when there is a calorie surplus. Maybe I'm way off base.
• quattrofan 5y ago
• sfx77 5y ago
  I don't believe this research. I think the measurement of burning calories might be flawed. If you don't burn more calories by exercising how does Michael Phelps have a six pack with his 10,000 calorie a day diet?
• sfx77 5y ago
  If this is true, how does Michael Phelps have a six pack with a 10,000 calorie a day habit?
• anonfornoreason 5y ago
  What I feel much of this misses is the effect of exercise on metabolism. You have two energy pathways in your body, the quick glucose burning pathway and the slow and efficient fat burning pathway. By getting your heart rate up into the edge of the zone in which you are using that fat burning pathway but almost into the quicker glucose burning pathway, you work that pathway out and become more metabolically efficient / healthy. Yes you can lose weight or maintain weight without exercise, but you can still get diabetes or other aspects of metabolic syndrome. Plus exercise does help burn more calories. Sure it’s not as strong of an effect, but it helps. The more metabolically healthy you are the more capable you become of managing weight from what I can tell, but obviously to a certain degree you are a victim of your genetics.
• borroka 5y ago
  I am a scientist (biology field) and I have been exercising and playing competitive sports for more than 35 years at this point. I used to be a hard-nosed calorie counter and I got fantastic results by counting calories, which means I had visible veins in my belly area. I read Ancel Keys experiments, and I used to say that there were no fat people coming back from war back in the day: calorie reduction works. I used intermittent fasting, high protein, low-ish carb, daily variation in calories (e.g., 4 days at 1500-1800, 3 days at 2500). The pandemic starts, I had surgery a month before the working from home mandates, I stopped smoking (5 cigarettes a day, we know they tend to suppress appetite, but it not like meth, there are plenty of fat smokers) and I quickly, say in two months, put on around 10 kg (90 to 100 kg+), and for the first time since I was an early teenager, I had a belly. I was exercising less, not counting calories at all, I was not spending calories going outside (work, errands, nights out all got cancelled), and I was hungry all the time despite eating more than usual. All factors that can explain my weight gain. This unfortunate situation goes on for one year more or less, then I started losing some weight by simply eating less and going out more, at least that was my explanation. But I noticed a visible change in body shape and composition after a two-week vacation in which my diet was McDonald's at nights and a huge breakfast in the morning with all calorie-dense food, basically. Fast forward a few months, some improvement here and there, but I am still not at my pre-pandemic fitness level, still a bit fat, muscles not as visible as I like. I then go to NYC for a couple of weeks and my diet is McDonald's, ice cream and nothing of the healthy sort. Sure, humidity, heat, walking much more, they can all contribute to non-trivial increase in energy expenditure. But I come back looking like a million bucks, pre-pandemic fitness level if not better. I keep in shape, then I get covid and I pretty quickly put some weight on (again...), say 5-10 pounds (sure, these swings are also water stored in glycogen, some of the weight quickly gained also goes away pretty quickly). I then go on a long-weekend vacation, walk much more than usual but no exercise (gym, running, combat sports), eat and drink more than usual, and, again, I observe a visible change in my body composition. I am leaner, I lost weight, I see (some) abs. Someone could say, you are simply exercising more via walking and other non-exercise related energy expenditure, and MCDonald's two times a day can be at < 2k calories, which is plenty deficit for my body to lose weight. But as someone who has been tracking calories for a long time and has exercised for decades, I don't think it explains what I am seeing. I have problems now accepting that our metabolism and our physiology is not a lot more malleable than I (and science) thought it was. I now start to believe that our "state of mind" (conscious or unconscious) can have a much bigger effect on our physiology, including metabolism, than expected according to "settled science". I am talking about our "mind" perceiving a new state of world (vacation for example) and very quickly adapting to the new perceived "stress" by changing my physiology, it could be different nutrient partitioning (decrease insulin resistance?) or simply higher metabolic rate. Or it could be the opposite, such as perceived "normal life" as stressful thus increasing, say, insulin resistance, and vacation as "relaxed mode", decreasing cortisol and insulin resistance etc. We all know we can "think" ourselves sick, but we "think" ourselves leaner?
• themagician 5y ago
  I have always thought it pretty straight forward: you consume food and some of the carbon atoms become part of you. When you exhale, carbon atoms leave you in the form of CO2. When you exercise your breathing increases and thus you exhale slightly more carbon. You can only breathe so fast for so long.
• amai 5y ago
  "He calculates that the ceiling for an 85-kilogram man would be about 4650 calories per day. Speakman thinks that limit is too low, noting that cyclists in the Tour de France in the 1980s and ’90s exceeded it. But they were injecting fat and glucose directly into their bloodstreams, a practice Pontzer thinks might have helped them bypass the physiological limits on converting food into energy." Is this really true, that cyclists are injecting fat and glucose directly into their bloodstreams? I can't believe that. I have never heard that before.
• rootusrootus 5y ago
  What always gets lost in discussion about weight control, IMO, is that it is a mental game. The biological aspects are pretty easy. CICO works. Diets are a strategy for achieving CICO. And ultimately whether you can stick to it is largely a mental thing. So if you want to lose weight, figure out first why you have a problem to begin with. Because if you don't, then you will lose for a while purely through motivation, and then gain it back when your focus changes to something else. Of course, there are physiological inputs to the state of mind, as well, which may very well be uncontrollable and largely genetic, so even if you achieve your personal ideal it may not be the body you dream of.
• France_is_bacon 5y ago
• fian 5y ago
  To lose fat, the biochemistry requires conversion of long chain hydrocarbons (fats) to carbon dioxide and water. For a good explanation see: https://www.abc.net.au/catalyst/where-does-fat-go/11015048 https://www.abc.net.au/catalyst/where-does-fat-go/11015048 To burn fat, you need to eat less food so you tap into your fat stores, but you also need to breathe in oxygen and breathe out the carbon dioxide and water. Exercise essentially helps to decrease your glycogen stores so you get to a fat burning state and in breathing more which will help get more oxygen for the reaction and expel the carbon dioxide and water that are produced.