Around 80% of people who lose weight by dieting end up gaining it back within two years.  And a lot of them end up heavier than they were before.  Obviously, the secret to staying thin LONG-TERM is exercise.

But that's definitely not the only factor.  Here's a list from Yahoo of six habits skinny people have.

1.) Don't Skip Breakfast. You've probably heard this before, but when you skip meals, your metabolism slows down.  And people who don't eat breakfast are almost five times more likely to be obese.

2.) Drink a Lot of Water. Researchers at Virginia Tech found that people who drank two glasses of water before a meal ate a lot less than they would have.

And compared to people who DIDN'T drink two glasses of water, they lost 30% more body fat over the course of three months.

3.) Weigh Yourself Every Day. I'm not sure it's something "skinny people" do in general.  But it's something you should try if you WANT to be skinny.

A lot of diet plans tell you to weigh yourself once a WEEK.  But according to a study at the University of Minnesota, weighing yourself every day is more effective.

4.) Don't Eat in Front of the TV. It's referred to as "mindless eating," and a study at Cornell found you consume 40% more calories when you do it.

5.) Stop Worrying So Much. A ton of studies have linked weight gain with stress.  And people with CHRONIC stress specifically tend to gain more weight around their waist.

6.) Get Enough Sleep. Sleep and stress basically go hand in hand.  Most of us require seven to eight hours of sleep a night, and if you get less than that, you're more likely to start gaining weight.

The good news is, if you normally get five hours a night . . . then you start getting seven . . . you should start losing weight, even without exercising.