Negative calories foods??

quetzalcoatl

I've heard a myth that some foods work out to be negative calories - the reason is supposed to be that the body expends more energy digesting them than they yield. Carrots and lettuce, high cellulose type foods. Obviously any number of sites will list these foods as having calories in the positive.

Just wanted to clarify: is the calorie count a measure of the energy inside the food without counting things like the energy of digestion? It seemed obvious to me that that is the most objective way to do it. If that is the case, does anyone know whether carrots and such are in fact going to yield less energy than they cost to break down?

Seems a bizarre question but I'm curious. Thanks.

cacrat

There are certain types of foods that result in a negative balance of calories, the one that comes to mind is celery. But I don't believe carrots are one of foods. All foods have some type of calories in them. So yes, the calorie count is a measure of the energy inside the food without counting things like the energy of digestion. The energy someone expends on eating a type of food, or even just living, will be different from person to person.

MoonShadow_1au

Yes, celery is the only one I have heard of. Basically it is water and some green fiber that is not able to be absorbed (hence effectively 0 cals) take that away from your body processing it and you get a negative cal food.

wolfchild59

They don't exist. http://www.answerfitness.com/269/negative-calorie-foods-fact-fiction/

An excerpt from the above link:

Is Celery Really a Negative Calorie Food?
While the list of negative calorie foods has ballooned to include everything from beets to strawberries and mangoes (yes, I’m being serious here), celery is the most commonly cited negative calorie food.

From a nutritional standpoint, celery is pretty much empty. It’s basically made up of water, sodium, some trace minerals and something called cellulose — which is a form of vegetable fiber than the human body cannot digest. It contains no protein or fat and marginal carbohydrates. Any other nutrition in celery is in the form of vitamins, minerals and enzymes, which contain no calories.

In fact, aside from iceberg lettuce and cucumbers, you probably couldn’t find a less nutritious, lower-calorie vegetable to eat. These foods are already about as close as you can get to eating zero calories. Close, but not quite, as we’ll see in a moment.

A large, stalk of celery weighing in at 2.2 ounces contains only nine calories. Negative calorie diet advocates claim that the mere process of chewing and digesting celery requires an expenditure of energy that exceeds the 9 calories present in the celery. Therefore, the argument goes, celery has “negative calories.”

Again, this all sounds good in theory, but what about in practice?

Issues with the Negative Calorie Foods Theory
There are some flaws with the negative calorie food theory, however.

First, the reason that certain foods like celery are already low in calories is exactly because of their high-non-caloric nutritional content. The fact that cellulose, water and minerals like sodium contain no calories is already figured into the food’s caloric-content. That’s why it has minimal calories in the first place. Negative food advocates want to double-dip here, and have you believe that the non-caloric nutrients like cellulose lower its effective calorie levels even more, but that’s just not how it works. This is already baked-in.

Second, the whole argument that the body burns more calories chewing and digesting negative calorie foods like celery is also suspect.

Yes, the body does expend a certain amount of energy to digest food, but that expenditure — even with foods that contain a high-percentage of non-caloric nutrients like cellulose — is actually fairly minimal.

Typically, the body will expend 10 - 15 percent of the calories you consume each day to fuel digestion. Let’s just throw the negative calorie food gurus a bone and say that for foods that are rich in non-digestible nutrients like cellulose, that number is actually as high as 50 percent of calories consumed (I have no evidence for this claim — I’m just being generous to prove a point.)

In the case of celery — the poster child of all negative calorie foods – you would be burning an extra 4.5 calories per each 9 calorie, 2.2 oz serving of celery. That would put your effective net calories at 4.5 (9/50% = 4.5 calories) — hardly “negative calorie” territory.

And because the amount of energy expended on digestion of foods is always expressed as a percentage, to have a negative calorie effect, digestion would have to constitute at least 101% of the energy consumed in order to create a negative calorie environment — something which is physically impossible.

So it appears that the food that is the best candidate for qualifying as a negative calorie food — celery – can’t even hit the break-even point, let alone become “calorie-negative.”

quetzalcoatl

They don't exist. http://www.answerfitness.com/269/negative-calorie-foods-fact-fiction/

Thanks heaps. I suspected it was a myth, but this has really clarified things for me. Much appreciated!

pisceanprincess

I remember my doctor told me to eat a lot of negative calorie foods in January when I had my physcial. LOL, I didn't listen to her.

iverayna

Negative Calorie Foods ~ Vegetables
asparagus, beets, broccoli, cabbage (green), carrots, celery, chicory, chili peppers, cucumbers, endive, garlic, lettuce, onions, papayas, spinach, turnip, zucchini

Negative Calorie Foods ~ Fruit,apples,cranberries, grapefruit,lemons,mangos,oranges,pineapple,raspberries,strawberries,tangerines