I believe people here were not talking about "behavioural treatment". What is that even? I'm talking about people resolving to do something and following through.
Again, we can not change other people. People can only change themselves.
Then they didn't stick to it, simple as that. Eat less than you burn = lose weight. Unless they broke physics, in which case we should put them in a sterile room and study them
No. Even nearly a decade of intensive behavioral treatment has highly variable results.
Here's what the numbers tend to look like in practice:
As you can see, results cannot be guaranteed.> positive changes in life, quality, happiness etc are massive
This is generally true. Eating better and exercising will improve your life.
But will you lose weight? How much weight? Those are far more difficult questions.