Wheeze

We could bandy about traditional diets until the cows come and, indeed, I might point you to the traditional Scottish west highland diet of oats, potatoes and herring - high in (starchy) carbs, low in fat (v low in saaturated fat) and low in protein which many would argue is perfect - but both diets to some extent and the Kalahari Tribesmen's in particular developed through 'availablity' rather than choice.

What matters rather more is, when we have the choice, what is it we choose?

"Fat burning rather than sugar burning" is an attractive sound bite and what is considerably more important to an athlete, an endurance athlete, is whether 'fat burning' can produce fuel fast enough for 'running muscles'. Unless you run very slowly indeed, at less than 65% of MHR, the answer is that 'fat burning' cannot produce fuel fast enough for running muscles.

Every marathon runner carries round the course enough body fat to fuel the entire marathon, in fact many marathons, but the energy just isn't available - fast enough. Endurance athletes need carbs - starchy, slow release carbs to run on and to live on and fast release carbs to replenish depleted glycogen stores with. Athletes don't need a high fat diet and can't use the fat as a significant energy source when running. That is another reason why a "High Carbs, High Protein, High Fat" diet is bobbins.