[chmod775]

Success rate also isn't the same as difficulty.

It's very easy to fill out a lottery ticket, but success rate is very low.

Success is a boolean condition that often first needs to be defined, while difficulty is a spectrum and a more rigid concept. Really the only complication is subjective vs. objective difficulty (what is objectively difficult may be subjectively easy to someone practiced).

Difficult things require hard skills. Reducing someone's calorie doesn't require any hard skill that I am aware of.

[throwthere]

> Success rate also isn't the same as difficulty.

> It's very easy to fill out a lottery ticket, but success rate is very low.

> Difficult things require hard skills. Reducing someone's calorie doesn't require any hard skill that I am aware of.

I don't really want to engage with those statements other than to say I think morbidly obese people do have quite a hard time losing weight.

[chmod775]

> hard time

With which you mean the process causes discomfort? Probably less so than being asthmatic and/or a host of other things, but yes.

Other than that there can be some psychological issues that make self-controlled treatment subjectively hard or impossible. But then we'd have found another condition that would need to be treated first, getting us back to where we started: Somebody running a study on the efficacy of a diet probably would want to preclude people psychologically unable to stick to it...