If you fuel your body with a lot of fat, say a stick of butter, or a half cup of coconut oil per day, then throw a sweet potato and rice on top of that, doesn't your body burn the potato and rice first, storing the fat? So, if you choose the sweet potato or rice, should you limit additional fat? Eating high fat and any amount of starch has resulted in instant weight-gain for many a primal-eating person.Is it lots of fat- sans carbs and starch? Or carbs and starch-sans fat?
Or, is it- protein and veg, sans additional fat and starch?

P.S. sans= without, for the laymen.