So, the other day i had some pineapple and then decided to do a little research on pineapple's nutritional benefits. I came across an article that said pineapple was a "negative calorie" food - apparently it requires more energy to digest the pineapple than the pineapple actually provides (wa?) So i looked into it further and came across this: http://www.livestrong.com/article/28647-list-negative-calorie-foods/
A lot of the foods on there are fruits and vegetables and sea food, i.e. paleo compliant and so eaten all the time.
Now, the source of my confusion: when the powers that be say that the healthy caloric requirement is 2000 calories (for example)- how could they have calculated that? Is that 2000 calories absorbed after calories lost through digestion? Because if i have 2000 calories of fruits and veg i'll end up in deficit while if i have 2000 calories Of cake a day, goodness who knows!
Does that mean if i eat nothing but these "negative calorie" foods in unlimited amounts, i will lose weight? In fact, overall i'd be in a higher calorie deficit than if i ate nothing right? That doesnt make sense to me though.
It just shows how all this caloris value/requirements stuff is nonsense - two people eating 2000 calories and one enda up in energy deficit! Presumably, when they do these weight loss studies and have x number of participants all apparently consuming the same number of calories but not from the same foods, they do take this into account? Never come across it before though.
If anyone knows of any interesting articles on this please share!
asked byAylins (15)
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on March 19, 2013
at 06:45 PM
Your confusion is good, because that means you are paying attention! The number of calories needed a day seems to have become a written in stone limit for people to the point where they ignore several really important factors.
To me, they miss out on the most important factor of "what is the food I'm eating doing to me?" Sure, you can lose weight if you eat less than you burn, but are you losing muscle or fat or both? If you're not getting a full spectrum of amino acids, your body has to break down muscles to get them. If your insulin is high, your body with spare body fat over burning muscles. All that leads to a lower metabolism down the road, which lowers your "calories needed" amount.
In addition, it doesn't take into consideration that the food you eat can change how many calories you need a day. For instance, if I drank 1500 calories of alcohol in a day, I'll probably move a whole lot less than if I had an omelette and a salad and a steak for the same number of calories. If I could drink that much, I'll probably be comatose most of the day and hardly burn any more than my base metobolic calories just to survive.
If I eat sugary foods, I might get a good burst of energy, but the ensuing carb crash will slow me down shortly thereafter.
Also, if I'm energetic and have worked out, more of the food I eat gets used to repair my body and not for fuel, which alters the amount of usable calories I've eaten. That could be 10% or more of my intake!
Also, we have to remember that not every single thing we eat is actually used by the body. We've all had a run in with a very greasy meal. There's a lot of unused calories that went right through the body, if you know what I mean.
So, depending on my work schedule and the food I eat, I figure that I need anywhere from 1800 to 2800 calories a day. It seems a little silly to worry if I'm eating 20 more calories than 2000 in a day if my math is off by hundreds.
And all of this commentary is about weight. Calories are good for figuring out a very rough estimate for weight, but calories tell you absolutely nothing about how you're treating your heart or brain or liver, and if you're providing a breeding ground for cancer.
Don't focus on these negative calorie foods unless you are sure that they're good for you. Heck, I can lose a lot of weight taking crystal meth, but that doesn't mean it's good for me.
on March 19, 2013
at 04:54 PM
It doesn't make sense. There are some low-caloric raw veggies (for instance red cabbage, raw mushrooms, or some foods made of konjac flour(, which are in SMALL amount can cause a deficit in your body. The main point in it, that your system has to work a lot with the fibers, or, like in the case of raw mushrooms, you can't even digest its exoskeletons. The already mentioned fruits are containing a lot of sugar, and since your liver is the only tract which can process the fructose, it is really easy to get fatter with them.
on March 20, 2013
at 08:44 AM
Am I the only one who thinks this is a great question?
Aylins I am looking into this because I am really interested in finding out quite how this would work. It certainly isn't inconceivable that the digestion of certain food stuffs would require more energy then they provide. Hypothetically if all things were controlled I cannot see how a deficit would not be produced, although it seems very unlikely that the body could ever be in such a state. I am going to ask around some clever folks I know and update this answer.
Feedback as promised:
Can't find scientific evidence for that... not for any other food either, by the way. That said, if anything pineapple could (due to its digestive enzyme content) actually INCREASE not decrease the energy availability of the stuff you eat along with it. On the "hypotheses" you are asking. I guess even Pica does not provide negative calories. - Adel Moussa Ph.D.c.
And another friend:
The only real negative calorie foods are the ones you go out to buy but then do not eat. - MD.
on March 19, 2013
at 07:22 PM
That is a strange article, because it assumes that you need 0 calories to live and if you eat "negative calorie" foods you will lose weight and if your eat "positive calorie" foods you will gain weight. Not so.
Also I bet the calories that you "burn" while digesting the food do include the calories that you would have burnt in that time anyway..
e.g it takes 80 calories to digest 100g of broccoli (which has 25 calories).
If you hadn't eaten the broccoli you would have burnt 70 calories in the 2 hours it takes to digest the food, just sitting on your ass doing nothing.
If you add on an extra 10 for the specific purpose of digesting the broccoli, now your left with +15 calories from the broccoli.
This is just my theory... its like when you run on the treadmill, you are not really burning 800 extra calories above your normal "calorie allowance" because you need to minus off the calories that your would have burnt anyway, if you were just sitting watching tv for 90 minutes. 800(burnt)-200(would have been burnt anyway)=600 extra calories
Sorry to be so confusing, Hope you can see what I mean :)
on March 21, 2013
at 02:49 PM
Thanks a lot all!
@Mash - I wonder where on earth Livestrong got that from and why there's so much on it! Seemed to good to be true - guess i'll have to keep tabs on my pineapple intake!
@sarah - I understand what you're saying - it totally makes sense.