Sitemap

health advisory Hospital Doctor Yu 2007-11-8 19:08:36

Why isn't there a mechanism that determins when enough fat has been stored before it becomes unhealthy.

I mean, if I want to fill my gas tank more than capacity, the gas will squirt out of the tank. But the human body is like a gas tank which would grow the more as you put more gas.

It would be stupid to design a small car with a gas tank the size of a train. Nature should've predicted this.

Answers:

Your body's main concern is starvation. When you eat too much food, it packs away some for later, in the form of fat, in case food runs out. It doesn't seem like good design because we're not starving very often. But should food get scarce and come infrequently in large amounts (like when you manage to kill an animal once a week), your body will have the ability to keep you alive longer than if it just rejected extra fat like a full gas tank.

---

You underestimate the benefit to having a giant "gas tank". You'd be grateful for an expandable gas tank if you were constantly worried about where your next fill-up was coming from!

Your body's fat storage strategy evolved in an environment where food supply was *uncertain*! Storing as much fat as your body could possibly accommodate made sure you weren't *dead* by the time you next found food.

---

Fat storage mechanisms evolved while humans were still hunter/gatherers. There was no need for a limiting mechanism since humans were at best on the cusp of survival. A study on the onset of fertility in human females indicates that puberty is triggered by a ratio of body fat to total body weight. In a hunter/gatherer society, it was not a successful trait for a female to be able to conceive before she had enough energy stored as fat to gestate and feed offspring. Otherwise, the mother and child would perish during low food periods. Fat storage is only a problem for western cultures who have too much available food.

---

I've never considered that, but you're right! that's bizzare!