As mentioned, I have been looking more at carbohydrate intake as a key for muscle building. I just came across this interesting report that shows that many populations, including European-Americans, have more copies of a starch-digesting gene.
The report also contain this quote: "there's a growing movement among paleoanthropologists that suggests the dietary shift to more starch among humanity's earliest ancestors proved critical to our evolution".
Of course, there's a big difference between an evolutionary-type starch (i.e. sweet potato) and a modern one (french fries). But the fact that french fried potatoes have been and are so popular may be saying something. Though fries are often drenched in fat (and sometimes sugar), maybe people desire them because the starch is in accordance with their evolutionary heritage.
