There are many reasons we end up being overweight. You mentioned some here. Some can be addressed by the church if they're a spiritual problem such as addiction, unwilling spiritual accountability and others. I've been obese for many years and told many reasons for it by doctors and spiritual advisors alike, from medication side-effects to being oppressed by an evil spirit! It may take years, as in my case, of trial and error and various attempts at various solutions. So yes, the church may be able to help in some ways and a psychologist may be able to help in others. There's no cookie-cutter answer that can be preached in a sermon or taught in a bible study. For me it was a change of diet after a prompting during prayer followed by research. No one else could have told me that at the specific time and orchestrate my research so that it would make sense to me.