The New York Times posted an article about nutrition research involving desserts with breakfast in the mornings.  Believe it or not, the group that consumed dessert (and protein) with their breakfast in the morning lost more weight than the group that went with the low-carb diet after a follow up of 16 weeks.  Sounds like you just need a balance of the three— protein, carbs, and some sugar.  No mention of natural sugars but they did emphasize participants in the experimental got the choice of “cookies, chocolate, cake or ice cream for dessert”.

I’d love to see the results of another follow up of this study.  So far they’ve concluded that it’s okay to indulge; just do it in smaller portions.