It can be that our models for calculating TDEE, etc. are wrong and not accounting for a multitude of factors that might affect energy expenditure but still, it boils down to calories in -> calories out in the most simplistic level.
Calorie present != calorie consumed != calorie processed by digestive system != calorie deposited in the fat tissue
If all calories were the same, consuming 300 calories from a can of Coke and consuming 300 calories of green salad would lead to same outcomes. In long term they do not.
There's a reason why you lose weight if you have a tapeworm or have chronic diarrhea while eating the same amount of food isn't a mystery to the scientific community.
Most people don't see that much variation between the calories that pass their mouths and those that are digested by their GI tract. It's usually constant enough that calories in - calories out is enough to figure out how much you need to eat to lose weight. Even if there was a disparity between calories consumed and calories processed by the GI tract, that would only present itself as a "higher/lower metabolism" and wouldn't mean lowering calories wouldn't work to lower weight.
You can't get around physics and biology.
Okay, but that seems like an outlier case. The study I am looking for would be summarized roughly as "100 fat people start on a lower-calorie diet and increase their exercise routine over the course of 180 days. 98% of them (some statistical variation to account for weird genetics) consistently lose X pounds, a large group (60-70%) loses as many as Y pounds".
Most experiments that were set up that way either ended up reporting the results "inconclusive", or worse, as the caloric intake generally decreased, the weight increased http://www.amjmed.com/article/S0002-9343(96)00456-1/abstract
I am looking for the one, or two, or a dozen, that doesn't. Should be relatively easy to replicate.
"While this study didn’t track the women’s eating and movement habits away from the lab, it is likely that those who gained weight began eating more and moving less when they weren’t on the treadmills, “probably without meaning to,” Dr. Gaesser said."
Expending more calories via exercise increases one's weight when you eat more calories than you burned. There's nothing new there.
You'd think with a thesis this obvious it should be relatively easy to reproduce.
Hard to discuss the specifics of this exact experiment without knowing the details, but you have the control group that admits they have a weight problem and honestly tries to lose weight by signing up for this experiment. All of a sudden they turn into a bunch of cheaters buying up passes to an all-you-can-eat buffet? Is every obese person walking around extremely weak-willed? Is every thin person you see meticulously tracking their caloric intake and output?
What about entire countries that have low obesity rates? Are French or Koreans strong-willed at national level, consistently under-eating and over-exercising?
There are thousands of examples online of people who've lost weight and maintained that weight loss, not to mention the thousands of people who manipulate their weight at will to compete in events with weight classes.
Studies about diet and exercise are usually poorly designed and poorly funded, so they don't always accurately reflect reality and the existence of thousands of successes isn't invalidated by a poorly run study. Nor is our knowledge of basic physiology.
Rule of thumb: any study that relies on self-reporting diets is basically useless. It's not about lying. People are just really bad at measurement unless they explicitly measure every gram of food that enters their mouth. Intentions don't affect the quality of an implementation if you don't know how to implement something successfully. People who are underweight tend to eat less than they think and people who are overweight tend to eat more than they think.
Note that studies in which the number of calories a person consumes are tracked by the researchers leave no ambiguity in the direct relationship between the number of calories a person consumes and how their weight changes.
Distilling these issues into one of willpower is just incredibly misguided IMO and reflective more of the views of journalists who struggle with their weight and pass on the results of poorly designed studies. I addressed what I thought was a better way of looking at these issues in another comment: https://news.ycombinator.com/item?id=13827878
It's not as though Americans have "lost willpower" over the course of a couple generations. We just started eating more and moving less.
Why we started eating more isn't a mystery. Agriculture and food companies started processing food to be less satiating and more addictive by adding sugar and fat to sell more (a massive simplification of history, admittedly). Obesity wasn't an epidemic back when we were eating whole foods since they're so much more satiating and it's difficult to maintain a caloric surplus on a diet of lentils and vegetables or whatever.
As countries like France, China, Japan, and others who have more recently maintained their normal weights on a population level get introduced to these processed Western foods, they too are seeing their rates of obesity, heart disease, and diabetes go up.
That is correct. I am happy to fill that knowledge gap, though, if you have any links handy.
> studies in which the number of calories a person consumes are tracked by the researchers leave no ambiguity in the direct relationship between the number of calories a person consumes and how their weight changes
Can you point me to those?
These two links are great starting points, and link to the studies if you feel like reading them:
https://examine.com/nutrition/what-should-i-eat-for-weight-l...
https://examine.com/nutrition/does-metabolism-vary-between-t...
That is incorrect, but it does help sell gym memerships.
Moreover, expending more calories via exercise typically leads to weight gain, according to emprirical studies (and anecdotal look around gym's elliptical machines next time you're in one) https://well.blogs.nytimes.com/2014/11/12/exercising-but-gai...
Fat accummulation (and disposal) are governed by insulin, whose production is triggered by sugars and other carbohydrates.
Confusingly, consuming a high-fat, low-protein and zero-carbohydrate diet will also lead to a severe decrease in calories (as it's pretty hard to overdose on olives, coconut oil or lardo), but it's nevertheless a correlation.