I personally find it unbelievable that people don't understand how complex of a topic this is.

For example, you cannot explain why people are overweight people by saying they are:

- generically stupid

- ignorant

- lazy

- self-deprecating

- biologically inferior

- weak willed

Clearly there are other more fundamental issues involved. What psychological needs and stress are involved? What environmental factors are present (or missing)? I think that to a degree you can generalize this to things like drug consumption and addiction.

I believe people have their agency and I greatly admire those who start and sustain significant health improvements of any kind. There is a reason there are so many self-help charlatans: the real key to unlocking success is complex.