I know people who are sensible vegetarians and thrive on it, while I am at the other end of the Bell Curve. Right in the middle of a standard population distribution are lots of people who can eat lots of things.

Look at the people who grew up with the Four Food Groups. They look like circus acrobats compared to us today. It was a small percentage shift which had huge implications.

And me, who spent years of the 90's struggling to take care of myself with low fat, high carb, and high exercise? If I have to eat very low to make up for the times I ate very high, I can do that.