"More intelligence and fewer offspring?"

"Perhaps Idiocracy was stating a more general rule...."

But another thing...

When it comes to humans, for example, though our brains are only 2% of our bodies, they take up a whopping 20% of our energy requirements. 

If that's really true, it could be the key to why one person can eat heartily and never gain weight while the next person, eating the same thing, gets fat. Maybe it's a big brain/small brain distinction. Also, is it possible that instead of going to the gym or getting on a bicycle when we hope to lose weight, what we really should be doing is studying calculus or reading philosophy?

ADDED: Idiocracy primer: