Negative calorie foods ?

September 10, 2004 11:32 AM

Three vaguely questions on negative calorie foods and dried fruits.[MI]

1] I read recently about negative calorie foods - ones which release less energy than it takes to digest them. Is this a genuine claim (in your opinion)? Accepting that all diets should be ballanced, a food with negligable calorific impact would be good for my diet.

2] Dried fruits are often labeled as bad on diets mainly, it seems, because you can eat more of them than fresh fruits. Is this the only realistic difference?

3] Implied by the above, would dried negative calorie fruits still be negative calorie?

posted by twine42 to food & drink (16 comments total)

I've always been told (and believe) that most lettuces are a negative calorie food (espec. iceberg lettuce).
posted by o2b at 11:39 AM on September 10, 2004

Celery is widely held to be negative calorie. Sadly, there are no negative calorie fruits (all contain too much natural sugar), so your last question is moot, but if it were the case that 1 bite of X had -y negative calories, then z bites would logically have z*y, which would be negative also.
posted by benzo8 at 11:46 AM on September 10, 2004

Shoot!

"...but if it were the case that 1 bite of X had -y negative calories..."
posted by benzo8 at 11:48 AM on September 10, 2004

Anything that is mostly water or fiber (that is, undigestible plant matter) is technically "negative" calorie. Realistically, of course, this is silly. Such foods have so little energy stored in them that they are worthless anyway except as fillers. And if you need fillers, then your diet isn't balanced. If you are eating enough fat and whole grains, barring metabolic oddity, you will feel full when you have eaten an appropriate amount.

I don't know anything about the difference between dried and fresh fruits except, as you say, that one can eat a lot more dried fruit than fresh (fruit, in general, is mostly water, so this makes good sense). I don't honestly believe that *any* fruit can give few enough calories to be "negative" in this sense, although something like watermelon might come close. The fact is, fruit is mostly sugar, water, and fiber, and I doubt that any fruit has enough fiber to "negate" its sugar content (on preview, as benzo8 has noted).

And if you are just eating because you're bored or accustomed to eating, do something else instead. Sure, it's no fun at first, but once you get used to doing something other than eating, you'll be fine.
posted by uncleozzy at 11:57 AM on September 10, 2004

While I am sure it's accuracy could probably be attacked with vigour, this site implies that strawberries and mango are "negative calorie".

Dried, these would be great as snacks and in my (hypothetical) lunch box. Does this help my question?
posted by twine42 at 12:20 PM on September 10, 2004

according to Sweden's most popular nutricionist, there is no such thing (I would link it, but you wouldn't understand...). the closest thing would be eggs sans yolk.
also, I have no idea how to spell "nutricionist".
posted by mr.marx at 12:22 PM on September 10, 2004

i know of celery, peppers, pickled foods, and various herbs and greens for sure.
while without any calories, celery has been long held as a cleansing agent and detoxifier. peppers are full of vitamins and flavor but no calories. same for greens, sprouts and herbs with different benefits and tonic cleansing properties. pickles are basically iundigestible and pass (altnough i know of a case of someone dying from crazy pickle ingestion from lack of bodily processing) and some picled items also become mostly undigestable.
the intensification of the sugars in dried fruits is different from fresh without the live combinations that are usually beneficial.
live food is very good for you, although the raw food diets depend on how you deal with digesting them (read as gas). "live foods" like raw, fresh and active chains like unpasturized apple cider are very good for you. the apple cider thing does give you a boost from just the potassium.
mario batali and others have done things will raw foods and dehydrators that are really interesting, such as reducing lettuces and onions to amp the flavors.
posted by ethylene at 12:27 PM on September 10, 2004

Something to think about: a steak would be negative calorie if you chased down a cow, killed it with a spear, slaughtered it, built a fire, and roasted it.

live food is very good for you
Source?
posted by callmejay at 12:44 PM on September 10, 2004

I think some foods might be negative calories like celery but I don't know if it scales very well. If the page you liked to is truthful, which is debatable since they're trying to sell a $18.95 ebook, then eating 5 calories worth of celery burns 150 calories.

I really doubt that doubling the intake would double the net negative calories though. Think about it for a minue. A stalk of celery is about 5 or 8 calories (from google) and if it's true that you can just eat more to burn more calories you'd only have to eat 3 stalks of celery to make up for a chocolate bar. Three stalks of celery is very doable.

20 stalks of celery would be a negative 3000 calorie intake. I don't know if 20 stalks is actually doable but if it were, and the website was truthful then you could add 3000 calories of junk food per day to your diet and not gain the ~ 1 pound per day that you would expect.
posted by substrate at 1:44 PM on September 10, 2004

callmejay: raw (fresh, live) carrots are better for you than cooked carrots.
posted by five fresh fish at 2:30 PM on September 10, 2004

I know a guy whose diet in the summer months consists entirely of fresh strawberries (5 lbs. per day), plus the odd bit of fish (perhaps 1 lb per week).

As he is neither dead nor starving, I'm going with the theory that strawberries are not a negative calorie food.

If you really dig the strawberries, though, maybe you could adopt his diet...
posted by Mark Doner at 3:57 PM on September 10, 2004

Strawberries are, ah, "binding." That fellow probably poops only twice a year.
posted by five fresh fish at 6:13 PM on September 10, 2004

eating lots of strawberries seems to actually pick up the pace for me...
posted by namespan at 8:26 PM on September 10, 2004

Dried bananas are deep-fat-fried before they are dried, which, er, makes them a whole lot worse for you than fresh bananas. Don't know about any other fruits....
posted by armchairsocialist at 8:36 PM on September 10, 2004

Shit. I've been chowing down on a 5lb bag of banana chips, thinking they weren't altogether bad for me.

Enough of that, then. Sigh.
posted by five fresh fish at 8:48 AM on September 11, 2004

fivefresh: they aren't always "deep fried" but often have added hydrogenated fat and preservatives.
go apple chips except prepackaged always have preservative additives, bulk organics are cheaper and better.
thanks for posting the live food backup while i was off.
common sense and common knowledge are easy to find on it.
posted by ethylene at 3:12 PM on September 11, 2004