Why Do Some People Eat Whatever They Want But Stay Skinny?

We all seem to know a few of those people who haven't gained a pound for as long as we've known them, even though they seem to eat whatever they want, whenever they want. They're the people who everyone else is jealous of, the people who seem to defy the laws of nature. So what's the reason behind this infuriating phenomenon? The answer is probably more complicated than you think.

In the past, the ability to eat a lot without gaining any weight was generally written off as a byproduct of a "fast" metabolism, but that's most likely not the case. In a response posted on Quora, biologist Ian York debunks that theory by stating that "Human metabolisms are — barring disease — fairly similar across individuals; the differences in rates of burning food are too minor to account for the differences in ability to gain weight we see."

In reality, there are a few more probable scenarios.

One, some people just burn more energy over the course of the day — by taking the stairs instead of the elevator or constantly fidgeting, for example.

Two, some people have a body type that predisposes them to be either skinny or overweight. If they reach adulthood with very few fat cells, then they're less likely to be overweight.

Three, the body does a good job of regulating the amount of food that people need to eat, and while it may appear that they're eating all they want, these people probably aren't eating any more than they need to in order to maintain that weight.

And four, unless you're following these people around all the time, you really have no way of knowing how much exercise they get and how they eat when they're alone. They might only eat unhealthy food when they're out with their friends and spend the rest of the time at the gym — or eating chicken breast and steamed vegetables!