Why can't they do those things? All of them are easy steps. Sure, they take time, but so does the process of someone dropping a drug dependency.
It sounds a lot as though the obese then suffer a severe addiction if they can't make even small changes to their lifestyle in order to directly save and improve their lives on both short and long term scales.
If that's the case, shouldn't we be pressuring them to get help? Obviously i'm not sure how you feel about alcohol or opiate addictions, but assuming you think we should warn people of the dangers of drug overuse and addiction, shouldn't we do the same for the obese and their addictions?
Also, i am rather genuinely curious on one point:
What makes some people seem to have such a hard time compared to others? How come some people can consume the same food overall, but still maintain the ability to self regulate instead of greatly overeating?