[rgoddard]

When talking about a diet you want to break it down into several dimensions. 1) Does this diet lead to weight loss? This boils down to burning more calories then consumed. As mentioned in a different comment you can lose weight eating only twinkies. 2) Sustainability of diet - can the diet be maintained over the long term, and this plays in to the psychological challenge you mentioned. 3) Long term health effects - does the diet promote overall long term health or have potential negative consequences. Something like the twinkie diet most likely does not. i.e. does a twinkie have enough vitamin c to prevent scurvy 4) Interactions with personal health conditions - how does the diet affect your own current health condition. I am sure a diabetic would not fare well on the twinkie diet