Why Calorie Counts Are Wrong: Cooked Food Provides a Lot More Energy

By Richard Wrangham | December 8, 2011 9:10 am

by Richard Wrangham, as told to Discover’s Veronique Greenwood. Wrangham is the chair of biological anthropology at Harvard University, where he studies the cultural similarities between humans and chimpanzees—including our unique tendencies to form murderous alliances and engage in recreational sexual activity. He is the author of Catching Fire: How Cooking Made Us Human

When I was studying the feeding behavior of wild chimpanzees in the early 1970s, I tried surviving on chimpanzee foods for a day at a time. I learned that nothing that chimpanzees ate (at Gombe, in Tanzania, at least) was so poisonous that it would make you ill, but nothing was so palatable that one could easily fill one’s stomach. Having eaten nothing but chimpanzee foods all day, I fell upon regular cooked food in the evenings with relief and delight.

About 25 years later, it occurred to me that my experience in Gombe of being unable to thrive on wild foods likely reflected a general problem for humans that was somehow overcome at some point, possibly through the development of cooking. (Various of our ancestors would have eaten more roots and meat than chimpanzees do, but I had plenty of experience of seeing chimpanzees working very hard to chew their way through tough raw meat—and had even myself tried chewing monkeys killed and discarded by chimpanzees.) In 1999, I published a paper [pdf] with colleagues that argued that the advent of cooking would have marked a turning point in how much energy our ancestors were able to reap from food.

To my surprise, some of the peer commentaries were dismissive of the idea that cooked food provides more energy than raw. The amazing fact is that no experiments had been published directly testing the effects of cooking on net energy gained. It was remarkable, given the abiding interest in calories, that there was a pronounced lack of studies of the effects of cooking on energy gain, even though there were thousands of studies on the effects of cooking on vitamin concentration, and a fair number on its effects on the physical properties of food such as tenderness. But more than a decade later, thanks particularly to the work of Rachel Carmody, a grad student in my lab, we now have a series of experiments that provide a solid base of evidence showing that the skeptics were wrong.

Whether we are talking about plants or meat, eating cooked food provides more calories than eating the same food raw. And that means that the calorie counts we’ve grown so used to consulting are routinely wrong.

Part of the reason this had never been addressed before was that several areas of research had been overlooked, even by nutritionists. Especially fascinating were the physiological studies on people who subsist only on raw foods. I was impressed to learn that raw-foodists are thin compared to those eating cooked diets, given that in most cases they are eating domesticated foods with lots of nutrients, are processing them in machines like electric blenders, and of course, living as most do in the developed world, never suffering through seasonal food shortage. Yet despite all these advantages over anyone who might try eating wild foods raw, the average woman on a 100% raw diet did not have a functioning menstrual cycle. About 50% of women entirely stopped menstruating! When a raw-foodist’s reproductive system does not allow her to have a baby even when her diet is composed of processed, high-quality, agricultural foods, the obvious explanation is that she is not getting enough calories.

caloriesThe fact that these studies weren’t generally known may have been because cooking seems to fall into a gap between research fields. For instance, there has been a journal called Meat Science for more than 70 years and textbooks and multi-volume books called Meat Science, which study the production of meat all the way to the consumer’s mouth. But there the science stops. As a meat scientist wrote to me, “The problem of how cooking affects the caloric value of meat does not seem have been of much interest to meat scientists.”

Yet there were signs that cooking did affect the calorie counts of some foods. Starches, for instance, like those in wheat, barley, potatoes, and so on, are composed mostly of two sugar-based molecules, amylopectin and amylose, which, when raw, are tightly packed and inaccessible to digestive enzymes. Studies have found that cooking gelatinizes starch, which means that amylopectin and amylose are released and exposed to enzymes. Thus, cooked starches yield more energy than raw ones.

To study how cooking (and processing, like pounding or chopping) affected calories, we turned to mice. They are a good species for this because their diet choices are rather similar to human food preferences. They like grains, roots, fruits and even meat; in the wild, there are populations of mice that get most of their food by eating live albatrosses [video]. Rachel Carmody led a study in which mice were given regular mouse pellets for six days at a time, interrupted by four days of eating sweet potatoes or beef. Half the time the sweet potato or meat was presented raw, and half the time cooked; half the time it was also pounded and half the time unpounded. She and Gil Weintraub carefully measured the exact amount of food eaten by the mice, and then calculated the animals’ gain or loss of weight over four days as a function of the weight of food eaten, using both wet weights and dry weights of food to check the results. For both meat and sweet potato, Rachel found that when the food was cooked the mice gained more weight (or lost less weight) than when it was raw. Pounding had very little effect.

We suspect that there are two major reasons for cooked beef providing more calories than raw beef. In cooked beef, the muscle proteins, like the sugars in cooked starch, have opened up and allowed digestive enzymes to attack their amino acid chains. Cooking also does this for collagen, a protein that makes meat difficult to chew because it forms the connective tissue wrapped around muscle fibers. However, we do not know the exact mechanisms. What we do know, though, is that the mice had a spontaneous preference for eating cooked meat over raw meat, and their choice made sense, given that they fared better on it.

Mechanism aside, though, what the experiments indicated was some serious discrepancies in how calorie counts are measured. The USA uses the Atwater Convention for assessing calories in food, a century-old system that treats food as being composed of a certain number of components, each of which has a fixed calorie value–such as 4 kcals for a gram of protein, 4 kcals for a gram of sugars, 9 kcals for fats [ed: kcals are popularly called "calories"]. Modifications to the original convention allow advances in nutritional knowledge to be incorporated, such as better estimates for some specific types of carbohydrate. The system gives a good approximation for foods that are highly digestible and demand very little work by the digestive system, such as candy bars. It is convenient because it produces standardized numbers that everyone can agree on.

But the Atwater Convention has two big flaws. First, it pays no attention to the extent to which food has been processed. For example, it treats grain as the same calorie value whether it is eaten whole or as highly milled flour. But smaller particles are less work to digest, and therefore provide more net energy. Second, it treats foods as equally digestible (meaning, having the same proportion digested) regardless of processing. But cooked foods, as we’ve seen, are more digestible than raw foods.

These flaws matter. According to the Atwater Convention raw foods have equal calorie content to cooked foods. So people can be deluded into thinking that feeding their children on 100% raw foods is a healthy practice, whereas I believe it would be dangerous for them.

The more highly processed our foods, the more calories we get out of them. If you want to gain weight, make sure you eat highly processed and well-cooked meals. If you want to lose weight, do the opposite. You can eat the same number of measured calories, but if the foods vary in how finely they have been ground or whether they have been cooked, the calorie counts will not tell you what you want to know.

The next wave of research will decide how profound the effects of cooking are. My best guess, based on studies of the increased digestibility of starch or eggs eaten cooked compared to raw, is that the increase in net calorie gain from cooking will prove to be in the region of 25­­–50%. That is only a guess, but I am confident it will be much higher than 10%. It is going to be exciting to find out.

Image courtesy of michaelnugent / flickr

  • Cathy

    The most recent Weight Watchers program (PointsPlus) actually tried to take this into account, giving raw fruits and most vegetables an assigned point of 0, but ramping up the numbers as the foods are cooked or processed as part of recipes. A raw apple is “free” but the moment it’s processed and cooked into a tart, the calories are calculated into points. Whole grain breads are valued as less than white milled breads, etc.

    There has to be a balance – cooking food not only makes it tastier and easier to digest, but also makes it safer to consume. Even our raw veggies are frequently recalled due to bacterial contamination that can cause illness, to say nothing of trichonosis, salmonella, and E.Coli in meats.

  • Chris

    Very interesting. Can’t wait to start my raw monkey meat diet. Mmmm, monkey meat.

  • Susan

    Your book link goes to the wrong book in Amazon.com.

  • http://www.sciencebase.com David Bradley

    Interesting!

    Humans have evolved past the point of no return when it comes to cooked food, if I remember rightly you cannot survive on raw food alone. Is that correct?

  • http://www.shivasteveordog.wordpress.com Shiva Steve Ordog

    This is interesting work and it may lead to the conclusion that cooked food is “better” but I think that this is the wrong conclusion. Leaving aside taste and tradition, our country is overweight and this is due to too many calories and metabolic issues caused by an abundance of sugar, white flour, meat, and dairy in the diet. Using the data gathered here, we can see that eating raw fruits and vegetables, nuts, seeds, and the like will be a calorie poor diet. This regimen is also high in fiber and micronutrients, some of which are killed or eliminated in cooking and other processing. No need to eat raw meat – avoid meat due to the tendency of meat and dairy to increase heart disease, stroke, and cancer. It is not that no food should ever be cooked. It is prudent to evaluate the amount of nutrients and fiber gained compared to the calories consumed and reach a balance with more raw than cooked food. That is, if your purpose is to have maximum personal vitality and good health.

  • scott

    The link for his book on amazon goes to the 2nd title in the hunger games

    Ed: Our readers truly have eyes like those of eagles. Fixed now. Buy away! Tell Amazon we sent you.

  • Paul

    I know how I feel when I regularly eat raw foods and how I feel when I’m eating cooked and/or processed foods. People that like their cooked foods, I wish you the best, live long and prosper. As for me, I’m sticking to a high raw food diet.

  • Stuarticus

    It has often occurred to me that the temperature at which the food is consumed can probably make a fairly large difference as well, as your body has to do work raising the temperature of it.

    I sometimes wonder if drinking a lot of warm liquids (as opposed to cold water) can mean your digestive track is underdeveloped.

  • Ray Charles

    Do you have a source for the “Yet despite all these advantages over anyone who might try eating wild foods raw, the average woman on a 100% raw diet did not have a functioning menstrual cycle. About 50% of women entirely stopped menstruating! ” statement?

    Also, how does not cooking affect nutrient profiles?

  • Aleina

    Fish, to taste right, must swim three times — in water, in butter and in wine.

    http://goo.gl/lhfcl

  • http://brandoncole.org Brandon

    @Shiva Steve Ordog I read an article before but I can’t find it right now that stated the vitamins and nutrients that are destroyed or broken down in the cooking process actually are better for us because we can’t break down all chemicals and enzymes that are in the food. And by cooking it we start the procedure to break them down and in some cases destroy them, but it allows us better access to more of the vitamins and nutrients in some foods. I really wish I could find the article that I read about it.

  • zendick

    Well, cooking does not increase the calories of food, what it does is make accessible more of the calories contained in the food to a human’s digestive system.

  • David

    So just to clarify, are the current commonly used numbers – based on the Atwater Convention – the ones for cooked or raw foods, or a mixture of both?

  • Ryan

    @David Bradley: You can totally survive on a raw food diet, it is just more difficult to do so. You need to carefully watch what you eat to make sure you maintain a healthy balance. That you are getting all the nutrients you need. Vitamins, minerals, amino acids, etc. This may involve having to take supplements, though it is not a mandatory requirement.

  • Christine

    It is already known that homo sapiens evolved because of eating lots of meat and animal products, which was vital to fueling and growing our big brains. Cooking is also something that human beings developed, and apparently developing that technology also influenced our evolution. Fascinating stuff!

  • Mal Haak

    @Shiva Steve Ordog

    So basically the idea would be to combine raw and cooked as much as possible. Possibly even cutting down the portion sizes on cooked but not excluding any one of the two.

    Sounds like the old adage of “Everything in moderation” might have been onto something.

  • Brian Too

    Fascinating! This makes sense to me from a cook’s perspective too. When you cook many foods such as onions, they are often referred to as “caramelized”. I’ve always believed (assumed) that there was some process by which starches were cooking into sugars.

    To make tequila, the agave plant is cooked. Yeasts eat sugar and not starch, so it is my belief that once again, starches are being converted by cooking into sugars that the yeast will consume, producing alcohol as a waste byproduct (for them anyway).

  • Frazer Kirkman

    I eat a predominantly raw diet, and I need to point out that the comment about the average woman raw food eater stops menstruating is wrong. I know personally hundreds of raw food women, and have been on forums with THOUSANDS, and only ever heard of 1 woman were her menstrual cycles were affected.

    We get more than enough calories, because we focus on high calorie foods like fruit.
    Yes, cooking food increases the available calories – but lets face it – most people in todays society get way to many calories. Cooking also decreases the levels of many of the nutrients in food – which, you will all agree, are more important than just calories.

    The damage caused to the food by cooking is also something to consider. The by-products of the broken nutrients can be difficult for our body to process. Raw foodists have found themselves being cured of many diseases caused by the SAD diet (standard American/Australain diet).

    A feature film has recently been release that has a few examples. http://www.fatsickandnearlydead.com

    There are also a growing number of elite athletes who thrive on raw food – yes they eat a lot, but the effects on endurance and recovery time is remarkable.

    My hope is for every one who reads this to discover optimal nutrition, and live in good health.

  • Ape

    http://www.youtube.com/watch?v=OM0Bmsydg7Y An old documentary from BBC that covers this exact idea. Is this related?

  • Casper

    Very interesting – it all seems makes sense, so much that it’s actually surprising this hasn’t been taken into consideration yet…

    @David Bradley: I thought so too from my first reading, but “raw diet” nowadays is also vegetarian. I’m pretty sure a “raw diet” with (raw) meat, like it would be in nature, would be sustainable for humans…

  • https://www.syndk8.com Earl Grey

    wow
    i am astounded at that and was at the point of considering the caveman diet.
    this helps a lot with my decision

  • Wilford

    So does this mean I should eat roasted almonds instead of raw ones?

  • Kish

    Humans (and all primates) have short large-intestines and very long small-intestines whereas carnivores like lions, tigers, etc have the opposite, so raw meat, etc contains a lot more calories but we cannot break it down fast enough to absorb it in time before excretion. My guess is that calorie count is what food can potentially provide but not what we can fully absorb?

  • Regan

    Very interesting. So the caloric value of food varies according to how it is prepared. This makes me wonder – are there individual differences in how many calories people extract from their food? I always assumed that ingested calories were all inevitably absorbed by the body- but perhaps some people’s digestive systems are better at extracting calories from food than others? This might help explain why some people gain weight much more easily than others, for a given energy intake.

  • Chris

    @7 Brian
    Yeast can eat starch. They definitely prefer glucose, but if you’ve ever made bread they definitely break down the starch to grow.

  • Dr. Glenn Wehner

    Several misconceptions here. A calorie is a standard measure of energy value of a foodstuff and is obtained by a laboratory analysis. The main focus of any energy source (or any nutrient for that matter) is the digestibility of the foodstuff which is just a carrier for the varioous nutrients. It is like putting your favorite food in a glass container. If you can’t get to it (digest it) it will do you no good. Diet (Die it) is just that. By eliminating certain foods high in calories and replacing it with low content and/or low digestibility foods will decrease uptake by the body. Starch is just many glucose (sugar) molecules linked together and serve as an energy source for both the plant and humans. But again you must digest it to sugar (glucose) to absorb it. Sugar is sugar is sugar regardless of the source. Digestibility and concentration are the main concerns here. Reduce red meat consumption surely but current research as validated the need for animal protein in the global diet to offset protein and specifically essential amino acid deficiencies in the world. Meat is an excellent source of these amino acids and it is very digestible compared to proteins in plant sources.

  • Craig Rickel

    David Bradley: Humans have evolved past the point of no return when it comes to cooked food, if I remember rightly you cannot survive on raw food alone. Is that correct?

    No, it’s not. Humans can survive on a diet composed entirely of raw food. They simply cannot live well, as we are used to.

  • Mylene

    I may not have picked this up in the article, but does the Atwater Convention then generally measure calories of the raw version of a food component or the cooked version? In other words, when we are looking at the nutrient label of some packaged food, is the calorie count under- or over-reported?

  • Liz

    This is an interesting article but I would have to agree more along the lines with Shiva. Being a nutritional therapist I see people doing very well with higher amounts of raw foods than cooked in many instances due to micronutrients, fiber and vital enzymes both of which are largely cooked out of the food. The article brings to light some very interesting points, two of which are worth highlighting. That cooking liberates the proteins and starches that might not otherwise be easily liberated with just masticating (chewing) and via the digestive system. The glycemic index of a food is also higher when it is cooked. Therefore, striking a balance is important in the human diet as there are trade offs between cooked and raw foods.

    There are several things I think the author needs to be aware of. Studies have been done on eating raw meats and dairy with cats and the fact that this diet is really optimal for pets. Thus the raw dog food and pet product movement. In fact there is a famous study from Price Pottenger on the matter. It was about how successive generations of cats had hip fractures and lesser intelligence and agility after eating homogenized and pasteurized and cooked meats. The cats were much more vital and healthy when eating raw meat and raw milk. In fact it was concluded that this was the optimal diet. The overall vitality and integrity of their immune systems and health was compromised with cooked foods because vital nutrients were lost. Successive generations of animals were less healthy and vital. Humans do digest raw milk from their mothers and this is extremely important nutrition.

    The point about menstrual periods is simply not quite correct. Intense athletes often don’t have periods but have still gotten pregnant. Not having a period does not mean you cannot get pregnant. Additionally, I have studied raw foods for some time and know people who have gotten pregnant specifically because they switched to eating raw foods and that the raw foods made a difference for them in an already fairly healthy diet. Some of the reaching conclusions should be left out of the research. I find in nutritional practice and through observation of people on raw diets that they have a considerable measure of health and that people find they can be more raw over time. I think more studies should be done on what the physiological and biochemical differences are between persons who are on raw foods diets and those who are on very different/dissimilar diets than that. How does a body change after been a raw foodist for some time? Just one persons brief experience is not the whole story.

    What I think the article brings to light more is which specific nutrients are liberated or accentuated with cooking and how caloric content is effected in this instance. Gary Hobbs, a journalist, has brought to light the fact that eating more does not necessarily mean that you will gain weight. The idea of eating less and exercising more for losing weight has been debunked. What this article highlights is the fact that we need to begin looking at nutrition very differently and that there are many intricacies with nutrition and health.

  • AGuyHere

    So THAT explains why zombies are so hungry all the time…

  • aidel

    Just an aside — eating chimps/apes/monkeys, especially raw, is a very bad idea. It is one of the ways HIV continues to be transmitted.

  • rehana

    That’s a terrible way to describe studies like this–digesting cooked food can’t provide more energy than burning it. The calorie counts that are off are the ones for raw food, and possibly the recommended daily total.

  • Brian Too

    @Frazer Kirkman,

    Your comments are over-strong and suggest a bit of the religous conversion going on. It is most likely that your contacts are self-selected members of a raw food group. As such it will only contain people who are successful at living on such a diet.

    What have you done to correct for people who tried it and could not continue? Specifically, for women who limited themselves to raw food, stopped menstruating, and decided that was not something they wanted out of a raw food diet?

    Cooking does far more than simply make more calories available. Many foods become more palatable when cooked; cooking is also a major food safety issue. Bacterial and parasitic contamination concerns go way down when dealing with appropriately cooked foods.

    There are reasons most food is cooked and those reasons aren’t going away anytime soon.

  • rezzan khan

    Simply Glycemic Index of the food which explains the release of sugar from the foods is the basic of the theory. This holds true for carbohydrates, but applicable to proteins in terms of cooking effect on foods.

  • t

    The article doesn’t say how it measured the calories in the foods, except that animals who ate cooked foods gained more weight. This could be due to how cooking breaks down the FIBERS (structures) in plants, so it TAKES THE ANIMAL less energy to break foods down. So it’s quite possible that with a similar amount of calories in cooked foods, maybe even LESS calories in cooked foods, the animal gains weight by not burning calories. The author needs to SHOW how the foods themselves contain a difference in calories, and it’s not simply that the animal is more or less efficient at digesting them.

  • Pingback: Weekend Link Love | Mark's Daily Apple

  • Pingback: YOU’RE SPENDING TOO MUCH TIME IN THE KITCHEN…. and it’s causing you to gain weight. « SOLUTIONDOWN.com

  • http://TheGardenDiet.com Jinjee

    Yes, you can live on Raw Foods, quite healthily, and children can thrive on a balanced raw diet of fruits, vegetables, nuts, and seeds. Dark leafy greens must be included daily. These are the most nutrient dense foods in the world according to the ANDI, with the largest amount of nutrients per calorie. More raw food science facts: http://TheGardenDiet.com/science

  • Anonymous

    Dear Raw Foodists – there is a simple reason why your diet (while it may keep you skinny – aka “malnourished”) is sub-optimal for the human physiology:

    FAT SOLUBLE VITAMINS.

    Vitamins D, A, K2 and B12. All are essential, and best absorbed from eating animal sources of saturated fats rich in these vitamins (best sources are grass fed animals and wild seafood).

    Let’s also not forget the other essential fatty acids – conjugated linoleic acid (CLA) and EPA & DHA. All of which occur predominantly in animal foods.

    Eating a raw food diet – especially a raw vegan diet – leaves you far more susceptible to malnourishment.

  • amy w

    Where can I get raw chocolate?

  • zippy

    As a person who has studied primitive wildnerness survival, I would say a lot of this jibes with my experiences. I do not know about sub-tropical, or tropical climes, these are outside my circle of competence. However, in temperate climes, I can say that cooking wild foods definitely expands the diet. Some wild foods need to be cooked in two or three changes of water to make them palatable. I’ve even heard of soaking some wild roots in caustic lye to make them edible. I will say that fire is an extremely useful tool in the wilderness, and often not for the typical reasons you might suspect. For example, with fire you can purify pine pitch to make it more durable as a glue. You can harden sub-standard chert rock into a usable flint. Fire makes pottery possible.
    And many other things. I have no doubt that the mastery of fire was a transformative event for our ancestors in many ways, and that, as semi-intelligent beings, they would have exploited it in every imaginable way, in every aspect of their lives. I should add that, I am morally certain the first pioneer to master fire and bring it to his fellow man as a gift, was rewarded by being burned at the stake as witch, and then having his discovery expropriated by the tribal committee as their own idea.

    Oddly, I also have some experience in raw foodism. I will remind the dogmatic raw foodist that Zepher famously got quite ill with trichinosis from eating a wild raw mongoose ! With that said, I have observed that some people do well on various raw food diets, and others do not. I do not know why. I have never seen a 100% raw vegan that did well over time (though they may exist !) The ones that I saw do well over time included some type of raw animal products (usually dairy, or egg ). In the end, I am uncertain whether cooking was an advancement in human health, or a step backwards ? I am quite certain that it expanded our range of habitats into temperate climates, and likely sparked off a nascent proto-scientific revolution. If that leads us eventually to ward off some cosmic catastrophe , which might destroy all life on earth, then on balance, cooking may prove to be a good thing.

    These are modest statements of my viewpoints.
    Zippy

  • Pingback: anthropologyworks » Anthro in the news 12/12/11

  • Pingback: Links 12/13/11 | Mike the Mad Biologist

  • Scott

    Rehana, I thought so too. Turns out that’s not the way food calories are measured. They don’t put dried foods in a bomb calorimeter because you would be burning indigestible fiber. So instead they just make a conversion based on their ingredients, with each ingredient being broken down into protein, carbohydrate, and fat. I would be more concerned about the chance that these initial tests, done years ago, might not be accurate, or the conversions for that matter.

    Meanwhile, no one is complaining that our nutritional labels are using the same recommended daily intake (RDI) from 1968. Some of those values have changed quite a bit, not that I know anyone who’s counting. The larger issue is that no one spends time to pull out their calculator on these nutritional guidelines, and the people that do are likely the ones that don’t need to.

  • Revenwyn

    I grew up 100% raw food vegan (from a child to when I was 26) and did not receive my period until I was 27 because of it. Oh yes, and I was still 215 pounds because I was STARVING TO DEATH and my body hoarded every last bit of fat it got.

    I dropped to 150 when I ate beef, bacon, whole milk, fried potatoes, etc. And two years later, I’m staying there and have a regular menstrual cycle.

  • Pingback: Why I Don’t Count Calories | Mobile personal training : Greensborough, Macleod, Eltham, Heidelberg, Watsonia, Diamond Creek, Doncaster, Lower Plenty, Doreen, Ivanhoe, Fairfield, Plenty, Rosanna, Northcote, Clifton Hill, Mill Park, Viewbank, Briar Hill,

  • http://paleoaustindallashouston.com Paleo Girl

    I have run into this same question myself. I am a small time chef, and promote paleo lifestyle, but people often say “the paleo man did not eat cooked meat” but so evidence shows they understood cooking although they likely did not know that the raw had less energy.

  • Pingback: Reducing: An American Pastime « Tethered Swimming

  • Pingback: Lots of Links « Sceptically Fit

  • Pingback: Day 22: Mon 19th Dec – A bit of meat changes everything « The Journey of 1000 Carrots

  • http://aqarboursa.com عقار بورصه

    Excellent discovery. I thought that raw food is harder to digest.

  • Pingback: Good numbers | gingerzingi

  • http://brainscroll.wordpress.com RickRussellTX

    @Scott, I think you dismiss @rehana ‘s point too quickly. The bomb calorimeter provides us with an absolute upper bound on calories from protein, fat, and sugars. It doesn’t matter how the food is processed, cooked, ground, pounded, shredded or whatever — burning constituent proteins, fats and sugars in pure oxygen is going to give you the highest possible measurement of heat energy.

    The Wikipedia page on the Atwater convention gives some of the error bars on the component measurements.

  • Apryl

    To my knowledge, just because a woman stops menstruating doesn’t mean she has stopped ovulating. I have heard of MANY raw vegans (through message boards, internet, blogs, etc.) over the years that are able to conceive children. Animals in nature do not get their periods every month. When I was eating 100% raw vegan and stopped menstruating I could eat cooked food and get my period THE VERY NEXT DAY. Don’t you think that’s a little strange? Someone should study that.

    Another note, digestion starts in this order: in the hands, in the nose, in the mouth, and then from there. If we don’t touch, smell and chew our foods properly we are leaving out a huge part of how well we can absorb nutrients. Nutrition is important, even on a raw food diet. One can eat too many nuts and balloon to obese levels. Anyone on any diet can get fat if they’re eating too much or too much of something they don’t need.

    Lastly, not all cooked food tastes better. I feel like crap after eating cooked food. I grew up sick, in pain, and skinny with a bloated belly. Eating high or 100% raw vegan is the only thing that has eliminated most of my health problems. Unfortunately, the issues return when I stray from that path. I keep my animal products and cooked food to a bare minimum. I am no longer sick, skinny, or in pain.

    Different things work for different people. We all need to find what works for us individually.

  • Brad

    I Agree with Apryl.. Also.. (in this study) if they kept feeding the mice the cooked diet who knows the future of the mice.. studies have been done showing that when transferring to cooked food health goes down and down and later on the animals can not even reproduce check out pottenger cats study.

  • jan

    Well, the author seems to be missing the point. It’s not that raw foods have less calories than we thought. Cooked foods just have more that the labels tell us. Therefore, if we are calorically aware we know how to add up the calories in raw foods. It’s the cooked foods that are the real wild card.

  • rob s

    Excellent article.

    Perhaps it could be better stated as: “cooked food provides more energy to the human body than does raw food”. The calorimeter bomb measures the total amount of energy in the food. Then a calorimeter bomb would measure the amount of energy in the waste. The total energy in the food minus what comes out as waste minus the energy required to digest the food is the energy available for the body to use.

    strictly taking about energy: can the body use different types of food equally as efficiently: protein versus carbs (converted to sugars) versus fats. ditto different kinds of sugars.

    And of course the body needs food for more than just energy (calories).

  • Pingback: The Best Protein Foods for Brain Health. « Plate Smarter

  • Travis

    Just because the mice got fat doesn’t mean that the cooked beef has more energy, it could have just slowed their metabolism. Saying that cooking increases calories is thermodynamically ignorant. Imagine if we toasted a piece of bread until it was black. Does anyone know how many calories are in the carbon matrix. How may calories are in ash?

  • Pingback: indi.ca » Raw Beef Sushi

  • Dustin B

    Apparently, when meat is cooked the protein structure changes. I wonder how that effects its nutritional value. Maybe the mice gained more fat from cooked meat while the raw fed mice were more lean. Perhaps a body fat check could be done in the next study.

  • not your avg domo

    Wow! That’s quite the story. I will say that if a woman isn’t charting it’s impossible to really know whether or not she has ovulated. You can still have anovulatory bleeding (period without ovulating). I would be interested in seeing a study in which women charted their cycles while also being on raw food diets–I did read one study showing that women who ate full-fat dairy ice cream each week had higher overall fertility than women who didn’t.

  • cooter

    Plus your body doesn’t burn calories. A single calorie is the amount of heat needed to raise the temperature of 1 kilogram of water by 1 degree celsius. This is measured in a lab by burning the food. Our bodies do not burn food to generate energy. It is broken down by different chemical processes into ATP, a chemical used to keep our cells alive.

    Carbohydrates are very easily broken down into glucose (causing diabetes) which is easily converted to ATP. Fat and protein are converted to ATP by much longer and more complicated processes. A calorie is not a calorie and those different sources of calories lead to different amounts of weight loss or gain, ie 1 carb cal is not equal in energy to 1 fat cal, etc.

  • cooter

    Those fried potatoes and milk will give you diabetes assuming you didn’t already have it. Stick with the meat. Make carbohydrates rare treats in order to be healthy (carbs embeded with the fiber of a fruit are not bad, but still should be somewhat limited, and eaten raw or dried).

    • Revenwyn

      Actually, I’m fine. I do not have diabetes, I eat 18 tater tots a day and 3 eggs for breakfast, still weigh 150, have 17% body fat, do 90 minutes of cardio a day and 3 hours of weights a week, and can bench press 250. Don’t need your “help” thank you.

      • investimigatin’

        Hi Revenwyn, I was very skeptical about what you said about being at an unhealthy weight on a raw vegan diet so yes, as the internet is an open space available for anyone to look at your activity I decided to do some investigating and have a look at your other comments that are all available to me and everyone with a computer on your profile.

        If you have a look at the pictures of the comments you said below you said you eat bacon. That’s pork. You said you were fed a can of coup once a day by your family in abuse, really tragic if that did happen to you but that definitely does not make you a raw vegan for most of your life.

        Yes, I had to, what I heard from you was absurd and you were giving misleading information that affects other people from attempting at this diet which in fact is a healthy diet.

        Good day,

        the nosy raw vegan.

        • Steve French

          Probably didn’t have to, Sherlock Holmes. There are better ways to get a point across than stalking someone and calling them a liar.

          • investimigatin’

            You know what French, you’re right. I did attack her, and there are better ways. Thanks for pointing it out to me, gives me something to work on.

  • Revenwyn

    There’s a difference between stopping menstruation, and NEVER GETTING IT to begin with, like I did, because I grew up on a raw food vegan diet.

  • Victor Alfonso Martinez Soto

    This is an excellent article, however I think further studies are necessary. It could be that raw food requires more energy to consume? or could be possible that this is a matter of portions more that calories? I would love to read the full study on this subject.

  • Peeps Human

    Eating less and and exercising more has been “debunked”?

  • Peeps Human

    What point? Is this a rebuttal to a previous article? Is the author of this piece not aware of his own point? Empirical evidence is not opinion. It might be preliminary, poorly presented, or even misleading, but the accuracy of this article should not be measured by opinion, personal experience, or “common knowledge.”

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

The Crux

A collection of bright and big ideas about timely and important science from a community of experts.
ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »