We're all heard the myth before. "Eat celery! It burns more calories than it has!" So you grab a stalk of celery and chow down on the stringy veggie, but is it actually helping you lose weight?

People talk about "negative-calorie foods" all the time and how beneficial they are to your weight loss journey.

"A negative-calorie food would by definition consume more calories, for the body to handle it and process it, than is contained in the nutrient content in the food," says Tim Garvey, chair of the department of nutrition sciences at the University of Alabama, Birmingham. "Theoretically that's possible. In actuality there are no negative-calorie foods.

Specifically referencing celery, Dr. Garvey broke it down for people. "There may be just 10 calories in a larger stick, but the body takes only one-fifth that much to process. It's still calorie plus."

Another nutritionist, David Grotto, also points out that celery is rarely eaten on its own.

"It's more of a gateway to cream cheese or peanut butter," he says.

That's not to say that eating celery is a waste of time in terms of helping lose weight.

"These foods do fill up the stomach and increase satiety," says Dr. Garvey. So the celery might stop you from eating more, but it doesn't burn calories you've already consumed.

Another myth is that cold water burns more calories than warmer water because your body has to work to heat the water to body temperature.

"There's no research to say that cold water drinkers burn more calories," Grotto says.

Dr. Garvey says there's no one thing you can do to change your metabolism quickly and easily. The doctor, who focuses on obesity and nutrition, says there's really only one way to lose weight: eat fewer calories than you burn through exercise. Just the same, boring, old-fashioned, and slow process of eating well and working out.

Had you heard this myth about negative-calorie foods before? Let us know!