Sounds like a teacher who failed (or failed to take) adolescent psych. This comes across as a classic 'catalyst to an eating disorder' story. With adolescents today more conscious about body image issues than ever, the whole lesson just strikes me as insensitive.

Sorry, I don't want to start a flame war, but I just find the teacher's lesson plan completely distasteful. There are other ways to teach lessons about the potential values of a low-carb lifestyle that wouldn't necessarily have to include having your body "judged" by your peers. Feh.