You're right--if the school is forcing some students to take that class to lose weight, and is forcing them to follow an exercise regime, it should also force them to eat healthily. But that logic only applies to the students being forced to take the class.

Managing temptation is a part of losing weight. I've been on a new diet and exercise program for about a month now, and while I did go to Burger King today, I made way better choices (a Whopper Jr with no mayo and chicken tenders with honey mustard (total: 560 calories)) than I would have before (Whopper with a medium Coke and medium fries (total: 1440 calories). My sodium, fat, and sugar were way higher than if I cooked myself, but the calories weren't that bad. Sometimes I just want something convenient, cheap, and tasty--diet or no diet.

Walking past a KFC every day, and even going in and eating something there, can be a pretty important tool. I've found it easier to modify my lifelong habits than I have to abandon them.