Calorie counters, take note: Negative-calorie foods do exist
– sort of. Though it’s easy to find Web sites, blogs and rumor
mills that tout the magical properties of negative-calorie foods,
the concept – like so many lose-weight-quick gimmicks – is too good
to be true.
Calorie counters, take note: Negative-calorie foods do exist – sort of. Though it’s easy to find Web sites, blogs and rumor mills that tout the magical properties of negative-calorie foods, the concept – like so many lose-weight-quick gimmicks – is too good to be true.
So-called negative-calorie foods are items that burn more calories during digestion than the foods actually contain.
“Technically, there are foods out there that are so high in fiber, eating them burns calories,” said Marcia Byrd, clinical health educator at Kaiser Permanente Medical Center in Gilroy. “And when you eat things like broccoli, think about how much more chewing you’re doing versus eating something like white bread. So you’re burning more calories there. But all foods have calories, and thinking there are ‘negative-calorie foods’ is something that sets people up for failure.”
The Web site www.negatiivecaloriefoods.com lists fruits and vegetables claimed to be negative-calorie foods. Byrd went through the list and pointed out that the fruit items listed all have about 100 calories worth of natural sugar, or fructose, in every half-cup.
“Having fruits on this list makes me really nervous,” she said. “Sure, things like papaya are high in fiber, but they also have about 15 grams of carbs per serving. There’s no way you’d burn that just digesting the fruit.”
Other items that are high enough in fiber to technically be considered negative-calorie foods are asparagus, celery, garlic and turnips, she said.
But just because people actually burn calories eating these foods doesn’t mean the foods are the miracle answer to weight loss, said Jennifer Zapata, the clinical nutrition manager for Hazel Hawkins Convalescent Hospitals in Hollister.
“The effect of digestion wouldn’t be significant enough to make a difference in someone’s weight. Whatever small amount of calories you burn would be negligible,” she said. “Eating these foods won’t have any negative impact on a person’s diet, but eating them is not an excuse to stop exercising or watching fat intake.”
Dieticians call most “negative-calorie” foods “free foods” because they’re very low in calories and good for snacking, Zapata said. But calling them “negative-calorie” foods leads to the false implication that they burn excessive amounts of calories.
“Really, we don’t need to know what’s got ‘negative calories’ and what doesn’t,” Byrd said. “We need to go back to portion size. Eat what you like, just eat less of it. Remember that a serving size for most foods is half a cup, and the body can only metabolize about one and a half cups every three hours with normal adult activity.”
Rather than worrying about negative-calorie foods, Byrd recommended drinking eight 8-ounce glasses of water a day, eating three to five small meals a day to keep pace with the body’s metabolism, and exercising 30 minutes a day.
“Even if you watch an hour of television a night, you’re watching around 22 minutes of commercials,” she said. “That’s almost your half hour. You just need to get up and do something during commercials. Just don’t go to the kitchen.”
What’s Considered a ‘Negative-Calorie’ Food?
Negative-calorie foods listed on various Web sites, including www.negativecaloriefoods.com and www.healthrecipes.com, include:
Apples
Asparagus
Beets
Broccoli
Carrots
Cauliflower
Celery
Chicory
Chili peppers
Cranberries
Cucumbers
Endive
Garlic
Grapefruit
Green beans
Green cabbage
Lemons
Lettuce
Mangos
Onions
Oranges
Papaya
Pineapple
Raspberries
Strawberries
Tangerines
Turnips
Zucchini
Foods that technically are “negative-calorie” items, according to Marcia Byrd, clinical health educator at Kaiser Permanente Medical Center in Gilroy, are:
Asparagus
Broccoli
Cauliflower
Celery
Cucumbers
Garlic
Green beans
Green cabbage
Iceberg lettuce
Onions
Radishes
Spinach
Turnips
Certains kinds of zucchini
