If most people in the developed world have excess fat storage, why do our bodies signal hunger after only a few hours after eating?

Question

If most people in the developed world have excess fat storage, why do our bodies signal hunger after only a few hours after eating?

In: Biology

Answer 1

You have to remember that having _too much_ food is a pretty recent thing. Up until about 150 years ago (in the developed world) most of your life was spent ensuring you had _enough_ food; dying of starvation was a very real possibility if things didn’t go well.

So for a few hundred thousand years, our ancestors had to eat as much as they could whenever food was there because that might be the only food available for a _long_ time. Turning off hunger meant that you didn’t build up the fat reserves that would sustain you through the lean times.

It is only in modern society that the lean times never come, but our bodies haven’t evolved past the instincts that kept us alive for most of human existence.