I don't think anyone set out to be obese. A culture that teaches/encourages blaming one's self for obesity is contributing to the problem. Gradually gaining one pound a year is enough to get someone obese. Without regular measurement and substantial attention to intake/expenditure, anyone could end up with excess weight.
I think this is a key point, and is another one that separates issues of weight from issues of mental health at times...
I continue to think about this as I interact with or even see pictures of some phenomenal psychologists... who happen to be overweight or even obese. If you google various names, you will find that some of them have significant weight issues, yet are clearly psychologically healthy.
Having known and met some of those people, I can't help but recognize that sometimes there are reasons why this is. Sometimes, these psychologists travel a LOT to conduct or disseminate their research. Sometimes, their schedules are so busy that, when push comes to shove, they don't choose to use their time preparing healthier meals and exercising. Its a choice they are entitled to make. And some, in light of other perspectives and priorities, don't see it as a big deal. Arguably, in light of the traumas and tragedies experienced by some clients, you could see why working out isn't a priority to some (again, psychologically healthy) clinical psychologists.
That's when I'd argue that a life coach could be really helpful. Not necessarily a personal trainer who's going to take the "No excuses!" route... Let's be honest- psychologists who work with really significant problems could see that as a total lack of understanding about the real problems in the real world (i.e. "...people are suffering and dying around the world, and this PT is telling me I have no excuse to not work out 5 days a week? gimme a break...")
However, IMO personally (anecdotally) find that I cope better and experience the problems of my clients better when I am refreshed and energized. Lately for me that has come to mean that I am always seeking to get the nutrition that I need, and if I have to take shortcuts on one of the 2, I'll take the shortcut on exercising.
Clearly we continue to see what a complicated topic this actually is, even for ourselves. Therefore, I reiterate that I do take issue with the idea that weight issues are equal to mental health issues. Sometimes, yes... always? No.