Leangains: "Everything I've seen shows that the increase in fat use for fuel has everything to do with reducing carbs and nothing to do with increasing dietary fat per se.
Consider that the body will shift to using fat for fuel under the following conditions
1. lowcarb/ketogenic diet
2. protein sparing modified fast
3. complete starvation
What's the commonality? The lack of carbs. NOT the presence of dietary fat."