I don't think it can be summed up with "eat less and have some willpower" though. I think the problem is a bit deeper than that. It would be like telling someone who cuts themself, "Well ... there's your problem. Stop cutting yourself and show some willpower" and expecting that would cure them
Yes but someone who cuts themselves doesnt usually complain that they are mistreated by others because they cut themselves. I think that everyone in their lives gets made fun of for something and has to deal with it, now if your fat most of the time you can change your body type by doing phsyical activity and having a healthy diet, being lazy and eating fatty foods is not similar to cutting yourself although it is destructive, alot of people with weight problems eat because they are depressed about their weight and feel they cant change it, you dont see a cutter cutting because they are depressed with the fact that they cut themselves, its usually a underlying mental problem, while most people who are over weight and complain can fix it by taking an active role in their physical health so that they can improve their overall mental health as well.