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I agree that the study really doesn't support what the headline conveys nor does it support the opposite. Thanks for doing the work of downloading the supplemen

I agree that the study really doesn't support what the headline conveys nor does it support the opposite. Thanks for doing the work of downloading the supplemental data and pointing out the rather important details. A few years ago I decided to get serious about my many years of chronic obesity and started deep-dive studying nutrition science. I was appalled by the pervasive lack of scientific rigor in most nutrition science. Even widely accepted parts of public health policy, like the "food pyramid" that was preached to kids in elementary school, were based on shockingly weak observational studies with many uncontrolled confounding variables. Most of the "Large N" studies are based on "diary data." Essentially, asking people via written surveys to estimate what they typically eat and extrapolating that over years. Yeah, not kidding. In short, I used to assume "nutrition science" was a somewhat rigorous field akin to biology or chemistry but discovered, for the most part, it's not. My N=1 experience has been that cutting out most carbs was tremendously effective for my metabolism type and I lost 85 pounds in 7 months without increased exercise. Since then I've kept it off for four years by sticking to a rigorous low-carb diet. It was difficult for the first few months but my palette and preferences adapted and now I plan to never go back. Eating low carb has the side benefit of cutting out most processed foods which may have helped improve my health. However, I don't recommend what I did for everyone because I've learned that metabolisms vary enough that what worked great for me may not work great for you. Instead, my advice is to do your own reading, develop hypotheses and experiment on yourself until you find a combination that works for your body, lifestyle and goals. Ultimately, weight loss is obviously a function of calories in vs calories out but in practice there are different ways of achieving the necessary caloric deficit. For me, low carb worked because it altered my blood sugar-driven hunger cycle. In all my years of failed dieting I'd never tried cutting carbs before cutting calories. Turns out it's much easier to cut calories when you're not hungry!

cheese_goddess 5y ago
>> Most of the "Large N" studies are based on "diary data." Essentially, asking people via written surveys to estimate what they typically eat and extrapolating that over years. Yeah, not kidding. That is one kind of study. There are also studies that measure the amounts of nutrients, or their byproducts, excreted by study subjects. These usually have small study populations or are restricted to hospital patients etc. There are also in vitro studies or in-vivo interventional studies that are most commonly conducted on animal models, like the study in the article. So like you say, many of the studies that have the largest populations are questionnaire studies, or have populations that are not very representative of the general population. But it's very difficult, if not impossible in practice, to do any other kind of study on a large population, because it's very difficult to observe what a few thousand people eat day-in, day-out. The logistics of such a study would be absolutely mad. The results of such large-scale diary studies do not have great statistical power, but you are not right to say that there is a "pervasive lack of scientific rigor". A study can be rigorous while having low statistical power. Neither does a study absolutely need to conduct double-blind RCTs to be considered rigorous. For example, cosmologists cannot conduct experiments on black holes. Anyway "rigor" is not well-defined, whereas statistical power is an objective measure that can be calculated from the elements of a study. Whether this is done right is another matter and it depends on the study, but nutrition science is not exceptional in this. Btw, I'm not a nutritional scientist. But I hear your complain often and while I understand your frustration, I think you're allowing the perfect to be the enemy of the good. We know some things about nutrition, many with low certainty. But, what are we going to do? Ignore all the knowledge and evidence we have because it's not as much or as good as we'd like, and instead ignore the important questions about the food we eat? Edit: another thing I've noticed is that your comment accuses nutritional science of not being rigorous but at the same time it freely uses concepts from nutritional science, such as "carbohydrates" and "calories". Even grouping foods together in particular groups like "carbs" is a practice that comes from nutritional science. And nutritional science will certainly tell you that carbohydrates are high-energy foods that can cause weight gain if eaten in excess. So you, too, must accept that there is something in the work of nutritional scientsts that is useful to you. In that case, if I were you (if I was trying to adress some problems in the way I eat that is) I'd be very careful not to allow myself to selectively pick only those parts of nutritional science I like, and dismiss all the rest as "sloppy science". It's important to be aware that we all have very strong confirmation biases when it comes to food (me, for example, I make cheese so I'll never, ever believe it can be bad for you).
SturgeonsLaw 5y ago
> Even widely accepted parts of public health policy, like the "food pyramid" that was preached to kids in elementary school, were based on shockingly weak observational studies with many uncontrolled confounding variables. It's even worse in fact. The Food Pyramid was originally developed by the US Department of Agriculture, and then edited by the Secretary of Agriculture's Office, which represent the interests of the farming industry. USDA nutritionists initially made some healthier recommendations, but were overruled to cater for farmer's interests. Here's an excerpt from an essay by Luise Light, one of the USDA nutritionists who's recommendations were rewritten: "Back in the early ‘80s, I was the leader of a group of top-level nutritionists with the USDA who developed the eating guide that became known as the Food Guide Pyramid. Carefully reviewing the research on nutrient recommendations, disease prevention, documented dietary shortfalls and major health problems of the population, we submitted the final version of our new Food Guide to the Secretary of Agriculture. When our version of the Food Guide came back to us revised, we were shocked to find that it was vastly different from the one we had developed. As I later discovered, the wholesale changes made to the guide by the Office of the Secretary of Agriculture were calculated to win the acceptance of the food industry. For instance, the Ag Secretary’s office altered wording to emphasize processed foods over fresh and whole foods, to downplay lean meats and low-fat dairy choices because the meat and milk lobbies believed it’d hurt sales of full-fat products; it also hugely increased the servings of wheat and other grains to make the wheat growers happy. The meat lobby got the final word on the color of the saturated fat/cholesterol guideline which was changed from red to purple because meat producers worried that using red to signify “bad” fat would be linked to red meat in consumers’ minds. Where we, the USDA nutritionists, called for a base of 5-9 servings of fresh fruits and vegetables a day, it was replaced with a paltry 2-3 servings (changed to 5-7 servings a couple of years later because an anti-cancer campaign by another government agency, the National Cancer Institute, forced the USDA to adopt the higher standard). Our recommendation of 3-4 daily servings of whole-grain breads and cereals was changed to a whopping 6-11 servings forming the base of the Food Pyramid as a concession to the processed wheat and corn industries. Moreover, my nutritionist group had placed baked goods made with white flour — including crackers, sweets and other low-nutrient foods laden with sugars and fats — at the peak of the pyramid, recommending that they be eaten sparingly. To our alarm, in the “revised” Food Guide, they were now made part of the Pyramid’s base. And, in yet one more assault on dietary logic, changes were made to the wording of the dietary guidelines from “eat less” to “avoid too much,” giving a nod to the processed-food industry interests by not limiting highly profitable “fun foods” (junk foods by any other name) that might affect the bottom line of food companies."

cheese_goddess 5y ago

>> Most of the "Large N" studies are based on "diary data." Essentially, asking people via written surveys to estimate what they typically eat and extrapolating that over years. Yeah, not kidding. That is one kind of study. There are also studies that measure the amounts of nutrients, or their byproducts, excreted by study subjects. These usually have small study populations or are restricted to hospital patients etc. There are also in vitro studies or in-vivo interventional studies that are most commonly conducted on animal models, like the study in the article. So like you say, many of the studies that have the largest populations are questionnaire studies, or have populations that are not very representative of the general population. But it's very difficult, if not impossible in practice, to do any other kind of study on a large population, because it's very difficult to observe what a few thousand people eat day-in, day-out. The logistics of such a study would be absolutely mad. The results of such large-scale diary studies do not have great statistical power, but you are not right to say that there is a "pervasive lack of scientific rigor". A study can be rigorous while having low statistical power. Neither does a study absolutely need to conduct double-blind RCTs to be considered rigorous. For example, cosmologists cannot conduct experiments on black holes. Anyway "rigor" is not well-defined, whereas statistical power is an objective measure that can be calculated from the elements of a study. Whether this is done right is another matter and it depends on the study, but nutrition science is not exceptional in this. Btw, I'm not a nutritional scientist. But I hear your complain often and while I understand your frustration, I think you're allowing the perfect to be the enemy of the good. We know some things about nutrition, many with low certainty. But, what are we going to do? Ignore all the knowledge and evidence we have because it's not as much or as good as we'd like, and instead ignore the important questions about the food we eat? Edit: another thing I've noticed is that your comment accuses nutritional science of not being rigorous but at the same time it freely uses concepts from nutritional science, such as "carbohydrates" and "calories". Even grouping foods together in particular groups like "carbs" is a practice that comes from nutritional science. And nutritional science will certainly tell you that carbohydrates are high-energy foods that can cause weight gain if eaten in excess. So you, too, must accept that there is something in the work of nutritional scientsts that is useful to you. In that case, if I were you (if I was trying to adress some problems in the way I eat that is) I'd be very careful not to allow myself to selectively pick only those parts of nutritional science I like, and dismiss all the rest as "sloppy science". It's important to be aware that we all have very strong confirmation biases when it comes to food (me, for example, I make cheese so I'll never, ever believe it can be bad for you).

SturgeonsLaw 5y ago

> Even widely accepted parts of public health policy, like the "food pyramid" that was preached to kids in elementary school, were based on shockingly weak observational studies with many uncontrolled confounding variables. It's even worse in fact. The Food Pyramid was originally developed by the US Department of Agriculture, and then edited by the Secretary of Agriculture's Office, which represent the interests of the farming industry. USDA nutritionists initially made some healthier recommendations, but were overruled to cater for farmer's interests. Here's an excerpt from an essay by Luise Light, one of the USDA nutritionists who's recommendations were rewritten: "Back in the early ‘80s, I was the leader of a group of top-level nutritionists with the USDA who developed the eating guide that became known as the Food Guide Pyramid. Carefully reviewing the research on nutrient recommendations, disease prevention, documented dietary shortfalls and major health problems of the population, we submitted the final version of our new Food Guide to the Secretary of Agriculture. When our version of the Food Guide came back to us revised, we were shocked to find that it was vastly different from the one we had developed. As I later discovered, the wholesale changes made to the guide by the Office of the Secretary of Agriculture were calculated to win the acceptance of the food industry. For instance, the Ag Secretary’s office altered wording to emphasize processed foods over fresh and whole foods, to downplay lean meats and low-fat dairy choices because the meat and milk lobbies believed it’d hurt sales of full-fat products; it also hugely increased the servings of wheat and other grains to make the wheat growers happy. The meat lobby got the final word on the color of the saturated fat/cholesterol guideline which was changed from red to purple because meat producers worried that using red to signify “bad” fat would be linked to red meat in consumers’ minds. Where we, the USDA nutritionists, called for a base of 5-9 servings of fresh fruits and vegetables a day, it was replaced with a paltry 2-3 servings (changed to 5-7 servings a couple of years later because an anti-cancer campaign by another government agency, the National Cancer Institute, forced the USDA to adopt the higher standard). Our recommendation of 3-4 daily servings of whole-grain breads and cereals was changed to a whopping 6-11 servings forming the base of the Food Pyramid as a concession to the processed wheat and corn industries. Moreover, my nutritionist group had placed baked goods made with white flour — including crackers, sweets and other low-nutrient foods laden with sugars and fats — at the peak of the pyramid, recommending that they be eaten sparingly. To our alarm, in the “revised” Food Guide, they were now made part of the Pyramid’s base. And, in yet one more assault on dietary logic, changes were made to the wording of the dietary guidelines from “eat less” to “avoid too much,” giving a nod to the processed-food industry interests by not limiting highly profitable “fun foods” (junk foods by any other name) that might affect the bottom line of food companies."