[cm2012]

Thanks for following with a citation, but I am well aware of that research. The national weight control registry is a heavily self selected group of people who have already lost significant weight before joining - therefore weeding out most of the failure rate. And even then, only 20% of their audience lost over 10% of their initial body weight and kept it off for one year.

[drewcrawford]

That's not relevant. You said:

> you won't find any reputable study on the web where the average person lost 10%+ of their body weight and kept it off for five years. Not even one.

To refute this, it's sufficient to present a counterexample. Since many studies exist, and they are reputable, the only argument is whether the people in them are average.

You say they are not, because they lost weight. But that cannot be your whole argument, because if we assume average people don't lose weight we assume the premise you have taken up to prove.

So again: other than the fact that these people lost weight, what exactly is exceptional about them?

[glenra]

Hang on, has a counterexample been presented? Maybe we're reading the challenge differently, but I parsed "reputable study on the web where the average person lost 10%+ of their body weight and kept it off for five years" as meaning a study in which a bunch of already-overweight people were selected to try some specific intervention (eg, "follow this diet & exercise program") and as a result of the intervention the median outcome was to lose that much weight and keep it off for 5 years.

A study of only people who succeeded, selected for the study because they succeeded, tells you nothing about how effective their particular strategy is.

For instance, suppose there exists a Grapefuit Diet which has the following effect: 1% of the people who try it lose weight, 2% of the people who try it gain weight, and 97% of the people who try it see no effect. If you take 100 people, tell them to try that diet, that is the result you'll get - a result which tells you the strategy is no good. But if you look at the national weight loss registry you'll only find people who were in the tiny 1% for which that diet worked. In fact, even if there are a LOT of Grapefruit Diet successes in the registry, that just tells you how popular the Grapefruit Diet was, it doesn't tell you if the Grapefruit Diet works.

What we want is an intervention study where a bunch of fat people do some specific thing and that thing is actually effective at producing a clinically significant and stable amount of weight loss. Ideally we'd want them to lose enough weight such that they are no longer "overweight" and then maintain that state.

Does that study exist? Is there any study meeting that set of criteria? My impression is that it does not; there is in fact no non-surgical intervention known to "work". Which explains why people keep grasping at straws to find options that plausibly might work.

[cm2012]

Spot on.

[cwyers]

That's not how reputable or study works. You can't call something a study where people self-select in based on the effect being measured.