[briHass]

I would add that energy balance (i.e. don't get fat) is probably the most important thing, assuming a reasonably healthy diet. Conversely, there's no diet that will save you if you're carrying excess pounds and/or are gaining weight beyond what is the ideal body composition.

Many of the diet studies, as poor as they are, that show beneficial changes due to diet almost always involve fat loss from baseline. Whatever diet can satisfy you and keep the weight down appears to be the local optimum.