Honestly, you are just burning a bunch of done-to-death straw men. (esp. the common "only thing" vs. "most important") Obviously the effects will be different.

But the first and most important (!) factor for body composition and fatness is still caloric balance. As confirmed by a vast amount of experimental data in real humans under controlled conditions. Which is Jacques Point. Macronutrients (as well as micronutrients) do have very significant consequences (Leptin, Insulin blabla.). But that won't help at all if caloric intake/output don't match your goal. It seems you read some of that nonsense Gary Taubes & co perpetuate?

Source: I'm a med student & fitness professional, who also writes fitness books. And gets results.