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Obviously there are a large number of factors which affect the weight of a specific individual, and food intake and exercise are only two of them, but that blog

Obviously there are a large number of factors which affect the weight of a specific individual, and food intake and exercise are only two of them, but that blog's attempts to deny the causation behind the correlation looks far more highly motivated than anybody pointing out that trends in obesity mirror trends in diets and lifestyle changes. I mean, he handwaves away the statistic that suggests the mean US citizen's calorie intake increased by nearly a quarter over the period that obesity rose simply by saying "that's not a jaw dropping increase". He thinks a study in which people's food intake was increased by 50% showed a significant average weight gain in just three weeks undermines the argument that feeding a population an average 25% more per day for the rest of their lives could increase obesity! I'm actually less suspicious that calorie counts are an oversimplification after reading what he citates as evidence against them; you could make a pretty good case for diet being the sole cause of increased obesity in the US from the references he makes to argue it's unrelated! (Nothing wrong with the "lipostat" hypothesis he proposes as the alternative per se, but moving the cause of obesity onto "changes in how many individuals' bodies identify satiation points and metabolise food intake" doesn't result in a hypothesis which is independent from how diet has changed, it just complicates the causation a bit)

zamfi 4y ago
> mean US citizen's calorie intake increased by nearly a quarter over the period that obesity rose simply by saying "that's not a jaw dropping increase" I think the context here is that while 400 extra calories a day might seem like a lot, it's within the observed variability going back as far as we have measurements. Americans ate more calories in 1909 than in 1960, and were no more obese then. > He thinks a study in which people's food intake was increased by 50% showed a significant average weight gain in just three weeks undermines the argument that feeding a population an average 25% more per day for the rest of their lives could increase obesity Hmm, I think the point here is that there is more complexity than the "eat more, gain weight" hypothesis: there was wide variability in how much weight people gained when being overfed, and all of these people, when they stopped being overfed, lost the weight they'd gained effortlessly -- which is emphatically not the case for most obese folks today. This implies something is different about being temporarily overfed (which makes weight loss trivial) and what's causing the obesity epidemic (which makes weight loss very challenging). Also worth noting that the increased caloric intake also doesn't answer the question of what's causing people to eat more than they burn. (And again, there's not really any question that obese folks are eating more than they burn -- it's the only way to actually gain weight, after all -- the whole point of this line of inquiry is to figure out why.) I'll cite what they say about this: > From this study [0], for example, consider this sentence: "TDEE was 2404±95 kcal per day in lean and 3244±48 kcal per day in Class III obese individuals.” From this perspective, the average daily consumption per Pew being 2,481 calories per day doesn’t seem like much — that’s about what lean people expend daily. Obese individuals generally burn 3000+ kcal/day, and while not every modern person is obese, it does make the increase from 2,025 calories per day in 1970 to about 2,481 calories per day in 2010 look relatively small. [0] https://www.nature.com/articles/ijo2012172 https://www.nature.com/articles/ijo2012172
- notahacker 4y ago
  > Americans ate more calories in 1909 than in 1960, and were no more obese then. That's his assertion, but all we've got is a link to a complex dataset on "food availability" and his word for it (and some probably-unjustified ancillary assumptions about calorie burning between the two eras being similar, of course). Extraordinary claims, I think, demand a higher standard of evidence. > Hmm, I think the point here is that there is more complexity than the "eat more, gain weight" hypothesis: there was wide variability in how much weight people gained when being overfed, and all of these people, when they stopped being overfed, lost the weight they'd gained effortlessly -- which is emphatically not the case for most obese folks today. Sure. But that's furiously demolishing a straw man that there's no variability in weight gain between individuals whilst dismissing the actual finding that it takes as little as 3 weeks to show a clear increase in weight from eating 1000 extra calories as incidental. And he's trying to use it to argue against the notion that average calorie intake data consistent with the obese ~40% of the US population eating ~1000 extra calories on a permanent basis could have caused the latter group to have gained weight! > This implies something is different about being temporarily overfed (which makes weight loss trivial) and what's causing the obesity epidemic (which makes weight loss very challenging). One obvious difference is that people overfeed for longer. This doesn't seem to be a gotcha for the basic assumption "people eat too much" and nor does the fact that eating "too much" is obviously likely to be caused by different factors in different people. But whilst "people eat too much" might have little explanatory power, its not nearly as dubious as the blog's assertion that "diet and exercise are out as explanations for the epidemic" despite them being both consistent with macro trends and a change in one undoubtedly entirely to blame for some individuals' weight changes
  - zamfi 4y ago
    Wait, I think we’re talking past each other. “People eat too much” (where “too much” is defined not in raw calorie numbers but in terms of “more than burned or excreted”) is the obvious proximate cause, and I don’t think these folks are denying that. The confusing question is: why is everyone suddenly eating “too much” and seemingly unable to control it? Why does it now require willpower and dieting to not become obese? People in the 1960s had plenty of food access, plenty of cars, etc. etc., and did not have obesity rates in the 40%+ range. Their diets were not so different from today’s diets in terms of macronutrient composition, in fact they were probably worse: plenty of sugar, fat, etc., components that have since been demonized. Why are so many people eating “too much” now?

zamfi 4y ago

> mean US citizen's calorie intake increased by nearly a quarter over the period that obesity rose simply by saying "that's not a jaw dropping increase" I think the context here is that while 400 extra calories a day might seem like a lot, it's within the observed variability going back as far as we have measurements. Americans ate more calories in 1909 than in 1960, and were no more obese then. > He thinks a study in which people's food intake was increased by 50% showed a significant average weight gain in just three weeks undermines the argument that feeding a population an average 25% more per day for the rest of their lives could increase obesity Hmm, I think the point here is that there is more complexity than the "eat more, gain weight" hypothesis: there was wide variability in how much weight people gained when being overfed, and all of these people, when they stopped being overfed, lost the weight they'd gained effortlessly -- which is emphatically not the case for most obese folks today. This implies something is different about being temporarily overfed (which makes weight loss trivial) and what's causing the obesity epidemic (which makes weight loss very challenging). Also worth noting that the increased caloric intake also doesn't answer the question of what's causing people to eat more than they burn. (And again, there's not really any question that obese folks are eating more than they burn -- it's the only way to actually gain weight, after all -- the whole point of this line of inquiry is to figure out why.) I'll cite what they say about this: > From this study [0], for example, consider this sentence: "TDEE was 2404±95 kcal per day in lean and 3244±48 kcal per day in Class III obese individuals.” From this perspective, the average daily consumption per Pew being 2,481 calories per day doesn’t seem like much — that’s about what lean people expend daily. Obese individuals generally burn 3000+ kcal/day, and while not every modern person is obese, it does make the increase from 2,025 calories per day in 1970 to about 2,481 calories per day in 2010 look relatively small. [0] https://www.nature.com/articles/ijo2012172 https://www.nature.com/articles/ijo2012172

notahacker 4y ago
> Americans ate more calories in 1909 than in 1960, and were no more obese then. That's his assertion, but all we've got is a link to a complex dataset on "food availability" and his word for it (and some probably-unjustified ancillary assumptions about calorie burning between the two eras being similar, of course). Extraordinary claims, I think, demand a higher standard of evidence. > Hmm, I think the point here is that there is more complexity than the "eat more, gain weight" hypothesis: there was wide variability in how much weight people gained when being overfed, and all of these people, when they stopped being overfed, lost the weight they'd gained effortlessly -- which is emphatically not the case for most obese folks today. Sure. But that's furiously demolishing a straw man that there's no variability in weight gain between individuals whilst dismissing the actual finding that it takes as little as 3 weeks to show a clear increase in weight from eating 1000 extra calories as incidental. And he's trying to use it to argue against the notion that average calorie intake data consistent with the obese ~40% of the US population eating ~1000 extra calories on a permanent basis could have caused the latter group to have gained weight! > This implies something is different about being temporarily overfed (which makes weight loss trivial) and what's causing the obesity epidemic (which makes weight loss very challenging). One obvious difference is that people overfeed for longer. This doesn't seem to be a gotcha for the basic assumption "people eat too much" and nor does the fact that eating "too much" is obviously likely to be caused by different factors in different people. But whilst "people eat too much" might have little explanatory power, its not nearly as dubious as the blog's assertion that "diet and exercise are out as explanations for the epidemic" despite them being both consistent with macro trends and a change in one undoubtedly entirely to blame for some individuals' weight changes
- zamfi 4y ago
  Wait, I think we’re talking past each other. “People eat too much” (where “too much” is defined not in raw calorie numbers but in terms of “more than burned or excreted”) is the obvious proximate cause, and I don’t think these folks are denying that. The confusing question is: why is everyone suddenly eating “too much” and seemingly unable to control it? Why does it now require willpower and dieting to not become obese? People in the 1960s had plenty of food access, plenty of cars, etc. etc., and did not have obesity rates in the 40%+ range. Their diets were not so different from today’s diets in terms of macronutrient composition, in fact they were probably worse: plenty of sugar, fat, etc., components that have since been demonized. Why are so many people eating “too much” now?