Nah, humans can thrive with eating a huge variety of foods. The atkins-type diets, as far as I've seen, are followed by panda-bear-shaped folks who maintain that panda-bear-shape no matter what.
If we really understood (as a society) what truly makes for a good diet, people would be getting slimmer and not fatter.
IMHO, the most sensible diet advice comes from Michael Pollan: "Eat real food. Not too much. Mostly plants."