I really enjoyed this lecture I stumbled onto by Dr. Stephen Ponder-- who's been mentioned a lot here lately as the author of Sugar Surfing. He's a pediatric endocrinologist, CDE, and type 1 diabetic himself.
This is 1 full hour long and touches on a lot of subjects that pertain to how we eat in this culture, diabetes, and yes-- obesity, particularly as these pertain to children. It was an hour well spent for me. I recommend it.