WebMD 1:01: Why Do We Gain Weight?

I hate those people who can eat whatever they want and never gain weight.

Oh, me too! Those skinny little creeps, I want to strangle--

Wait, wait, wait, I literally don't hate them. It's just an expression.

Sorry. I'm just trying to lose a little weight, and I'm a little hangry right now.

Well, let's focus that hanger on something more productive, like why we gain weight.

It's pretty straightforward. If we take in more energy or calories than we use, we gain weight.

Fat from food is broken down into fatty acids, which can travel in the blood and be captured by hungry cells.

But fatty acids that aren't needed right away are packaged in bundles called triglycerides and stored in fat cells, which have an unlimited capacity. And those fat cells are then stored in my booty.

Genetics and environment can play a role in weight gain, too. But overall, to burn off one plain 500-calorie fast food burger, you'd have to run for about an hour.

[GRUNTING WITH EFFORT]

Well, great. Now we know why we gain weight.

But that fat that makes

him look "meh" in a Speedo served our ancestors on the Serengeti well. They only had a few meals a week. Between meals, most of their energy was from stored fat.

Oh, that sounds awful. I get cranky even if I miss linner.

Linner? -Yeah, that's the meal between lunch and dinner? I think I look skinny.