Why a calorie inside your body is not a calorie
The number on the packet comes from a steel container in which food is burned. Your body does something else with it: it absorbs, it negotiates, it answers with hormones and it shares with bacteria.
More guides from the nutrition cluster
The calorie is an honest unit of measurement. It simply answers a different question than the one most of us are asking. It tells you how hot your food burns. It does not tell you what your body builds from it.
You are standing in the supermarket, turning a bag of almonds around in your hand. 604 kilocalories per 100 grams. You do the quick math, put it back and take the rice cakes with 387. Decision made, on to the checkout.
I do this too. Almost everyone does. And in everyday life there is nothing wrong with it.
Except: the number on that packet was not measured on you. It comes from a calculation system of the 19th century, from average values of a test group. Your gut has a say in how much of that energy reaches you at all.
In my consultations I often hear this: I count everything, I am honest with myself, and still the math does not add up. I believe that. And I believe part of the explanation already sits inside the unit of measurement.
What to expect here
- Where the number on your packet comes from and what it measures
- Why whole almonds hold back roughly a third of their calories
- How much energy digestion itself costs
- Why the same calorie count can trigger different hormonal answers
- What your gut bacteria take off your plate and add to it
- Why calories are raw material and micronutrients are missing from the math
- Where the opposing view is right and physics pushes back
- What this changes in your everyday life, and what it explicitly does not
- Twelve questions I am asked about this on a regular basis
Where the number on your packet comes from
Picture a thick walled steel container filled with pure oxygen. Inside lies a dried sample of food. One spark, and the sample burns completely. The container sits in a water bath, and a thermometer measures how many degrees warmer the water gets.
That is a bomb calorimeter. This is exactly how the calorie was measured. It is a unit of heat, nothing more.
The American agricultural chemist Wilbur Atwater built a practical system out of this. He burned foods, then burned the stool and urine of his test subjects as well, and subtracted whatever came out unused. Three numbers were left, and you still use them today: about 4 kilocalories per gram of protein and carbohydrate, about 9 per gram of fat.
These factors sit behind practically every nutrition table in Europe. Nobody burns your cereal box. A laboratory determines the nutrients, multiplies by the factors and adds them up. The calorie figure is a calculation, not a measurement.
A team around Kevin Hall at the US National Institutes of Health had 20 weight stable adults live in the clinic for four weeks. For two weeks there was ultra-processed food, for two weeks unprocessed food, in random order. Both menus were matched for offered calories, energy density, macronutrients, sugar, sodium and fiber.
During the ultra-processed phase the participants took in 508 kilocalories more per day. Body weight rose by 0.9 kilograms and fell again by 0.9 kilograms during the unprocessed phase.
For you this means: the label said the same thing twice, the behavior said something else.
Hall KD et al. Cell Metab. 2019;30(1):67-77.e3. DOI: 10.1016/j.cmet.2019.05.008 · PMID: 31105044 [RCT, n=20]The calorimeter knows exactly one process: complete combustion. Your digestive tract knows dozens: chewing, emulsifying, enzymes, transport routes, fermentation, excretion. At every one of those points something can be lost or added.
The calorie is therefore not a wrong unit, it is a coarse one. It describes the potential of a food, not its fate inside you.
The calorimeter burns. The body negotiates.
The thread running through this articleAnd now you know why two foods carrying the same number do not mean the same thing.
The almond that keeps a third of its calories to itself
When you bite into an almond, you do not break every cell. In many fragments the fat still sits where it belongs: enclosed in cell walls made of fiber. Your digestive juices never reach part of it. What they do not reach leaves you again unused.
That sounds like a small thing. It is not.
A working group at the US Department of Agriculture around Janet Novotny had 18 adults eat under full control for 18 days, with 0, 42 or 84 grams of almonds per day. During the last nine days stool and urine were collected and analyzed in the calorimeter.
The measured available energy came to 4.6 kilocalories per gram instead of the calculated 6.0 to 6.1. Per 28 gram portion that is 129 instead of 168 to 170 kilocalories, an overestimation of roughly 32 percent.
For you this means: by these measurements, close to a third of the almond calories you write down never arrived in you.
Novotny JA et al. Am J Clin Nutr. 2012;96(2):296-301. DOI: 10.3945/ajcn.112.035782 · PMID: 22760558 [RCT, n=18]The same group repeated this with walnuts. A 28 gram portion delivered 146 instead of the calculated 185 kilocalories, roughly 21 percent less. The effect is not an almond special case, but it is not equally large everywhere either.
The most interesting part comes now. The same group tested the almond in several states.
| State of the almond | Measured energy | Relation to the calculated value |
|---|---|---|
| whole, raw | 4.42 kcal/g | clearly below |
| whole, roasted | 4.86 kcal/g | clearly below |
| chopped | 5.04 kcal/g | below |
| almond butter | 6.53 kcal/g | practically at the calculated value |
The same nut, the same nutrition table, roughly a third of difference in available energy, purely from grinding it. The butter was the only form close to the Atwater value, because the cell walls in it are already broken open. The machine took over the work that your digestive tract otherwise does not finish.
Edoardo Capuano and Anja Janssen at Wageningen University compiled how the structure and composition of a food influence digestibility at every single step.
Their finding: the food matrix steers the extent and the speed at which nutrients are released. Digestion is a synergy of mechanical, chemical and biochemical processes.
For you this means: it is not the nutrient list that decides what you absorb, it is the packaging the nutrients sit in.
Capuano E, Janssen AEM. Annu Rev Food Sci Technol. 2021;12:193-212. DOI: 10.1146/annurev-food-032519-051646 · PMID: 33395540 [Mechanism Review]Rachel Carmody and Richard Wrangham at Harvard University fed mice meat and starch rich tubers in four states: raw, cooked, pounded, and cooked plus pounded.
Cooking raised energy gain clearly, and the animals put on body mass without eating more. The effect was stronger than that of pounding alone. This is a mouse study, not a finding in humans.
The authors derive a weakness of food labeling from this: minimally processed foods are systematically rated too high.
Carmody RN et al. Proc Natl Acad Sci U S A. 2011;108(48):19199-19203. DOI: 10.1073/pnas.1112128108 · PMID: 22065771 [In vivo, mouse]Structure is a nutritional value in its own right. It appears on no label and still has a say in how much energy your body can draw out of a food.
So far this is well measured for almonds, walnuts and whole grains. For legumes, seeds and vegetables, measurements of the same quality are missing.
I have written in more detail about the degree of processing and your feeling of fullness in unprocessed food and satiety.
And now you know the first place where the packet value and your body reality part ways: absorption.
Digesting costs energy, and very different amounts of it
Do you know that feeling of warmth after a protein rich meal? Some people sweat a little after a big steak. That is not imagination, that is work running inside you right at that moment.
Digesting is energy intensive. Breaking down, absorbing, transporting, rebuilding, storing: every step costs something. The technical term is diet induced thermogenesis. This cost center appears nowhere in the calorie calculation.
Klaas Westerterp at Maastricht University worked through the literature on diet induced thermogenesis systematically.
With mixed food in energy balance the share lies at 5 to 15 percent of daily energy expenditure. The ranking is stable: alcohol produces the most, then protein, then carbohydrate, then fat.
For you this means: part of your food calories does not become available energy, it becomes heat. How large that part is depends on what you eat.
Westerterp KR. Nutr Metab (Lond). 2004;1(1):5. DOI: 10.1186/1743-7075-1-5 · PMID: 15507147 [Mechanism Review]You may have come across numbers like 20 to 30 percent for protein, 5 to 10 for carbohydrates and 0 to 3 for fat. I name them for what they are: orders of magnitude common in the nutrition literature, not values from a measurement study. What is documented is the ranking, not the range.
Sadie Barr and Jonathan Wright gave 17 adults isocaloric cheese sandwiches on two occasions: once multigrain bread with real cheddar, once white bread with a processed cheese product. Energy expenditure was then measured for five to six hours.
The whole food version cost the body 137 kilocalories, which is 19.9 percent of the meal energy. The processed version cost only 73 kilocalories, which is 10.7 percent. The feeling of fullness did not differ.
Important context: 17 people, one meal, one pair of foods. The direction is interesting, the magnitude cannot be generalized.
Barr SB, Wright JC. Food Nutr Res. 2010;54:5144. DOI: 10.3402/fnr.v54i0.5144 · PMID: 20613890 [RCT, n=17]Philip Karl and colleagues at Tufts University gave 81 healthy adults a provided diet for six weeks, either with 207 grams of whole grain and 40 grams of fiber per day or with refined flour and 21 grams of fiber.
In the whole grain group resting metabolic rate rose by 43 kilocalories per day, and the energy content of the stool rose by 57 kilocalories per day. On balance the authors calculated an energy loss higher by 92 kilocalories per day, with an identical calorie figure on the plate.
For you this means: whole grain costs in two places at once, at the top in turnover and at the bottom in losses.
Karl JP et al. Am J Clin Nutr. 2017;105(3):589-599. DOI: 10.3945/ajcn.116.139683 · PMID: 28179223 [RCT, n=81]For protein the data are particularly dense. Reviews consistently find the highest thermogenesis and the clearest satiety signals. What follows from that in the long run for body weight is less uniform than guidebooks suggest. Satiety as a body signal is explored by the spoke Full is a signal.
We treat calories like income. Physiologically they are closer to a delivery with a handling fee, and that fee varies in size and appears on no packaging.
This does not make the calculation worthless. It makes it blurrier than its decimal places suggest.
And now you know the second parting point: the cost of processing.
The same calorie, a different hormonal answer
You probably know both sides of this. There are meals after which you do not think about food for four hours. And there are meals with the same calorie count after which you open the cupboard door two hours later without knowing why.
That is not a character problem. That is signal processing.
Food is not only energy, it is also information. Insulin, ghrelin, leptin and GLP-1 respond to the composition, the pace and the structure of a meal, not to its calorie count.
Cara Ebbeling and David Ludwig at Harvard Medical School had 21 young adults lose 10 to 15 percent of their body weight. After that they received three isocaloric diets in random order for four weeks each: low fat, low glycemic and very low carbohydrate.
Total energy expenditure differed between the variants by up to 326 kilocalories per day. Leptin, cortisol in 24 hour urine and insulin sensitivity differed as well. None of the three variants produced a consistently favorable pattern.
For you this means: the expenditure on the other side of the equation is not a constant.
Ebbeling CB et al. JAMA. 2012;307(24):2627-2634. DOI: 10.1001/jama.2012.6607 · PMID: 22735432 [RCT, n=21]Belinda Lennerz and colleagues gave twelve overweight young men meals with a high or a low glycemic index on two occasions, controlled for calories, macronutrients and taste. Four hours later brain blood flow was measured by MRI.
After the high glycemic meal, blood sugar four hours later was lower, reported hunger was higher, and the nucleus accumbens in the reward system was more active.
For you this means: identical calorie counts can leave behind very different afternoons. Only twelve men, so a small but cleanly measured finding.
Lennerz BS et al. Am J Clin Nutr. 2013;98(3):641-647. DOI: 10.3945/ajcn.113.064113 · PMID: 23803881 [RCT, n=12]David Ludwig and Cara Ebbeling built the carbohydrate insulin model out of this. According to it, high glycemic carbohydrates steer energy into fat tissue through the hormonal answer, increase hunger and lower expenditure. I present this explicitly as a hypothesis. The authors themselves write that the feeding studies so far were neither strict enough nor long enough.
Nowhere is this clearer than with breast milk: a food that steers growth rather than only delivering energy. I have laid that out in breast milk, growth, hormones and calories. The everyday side sits in avoiding blood sugar spikes and, measured with a sensor, in the spoke 14 days of glucose sensor.
A calorie is a quantity. Your body, though, does not read quantities, it reads messages. Insulin, ghrelin and the reward system respond to composition and pace, not to the sum printed on the label.
And now you know the third parting point: the answer of your hormone system.
What your gut bacteria take away and add
Trillions of microorganisms live in your large intestine. They eat along with you. And they eat exactly what you cannot break open yourself.
Fiber counts as poorly available in the calorimeter. In your large intestine it is a currency. Bacteria ferment it into short chain fatty acids, and you take up part of them. In the Atwater calculation this hardly shows up at all.
Reiner Jumpertz and colleagues at the US National Institutes of Health studied 21 people as inpatients, with diets of 2400 or 3400 kilocalories per day. The stool microbiome was sequenced, and the energy taken in and excreted was measured in the calorimeter.
The microbiome changed within days. In lean people an increase in Firmicutes of 20 percent went along with about 150 kilocalories more energy gain per day.
Important context: an association in 21 people, not a demonstration of causality.
Jumpertz R et al. Am J Clin Nutr. 2011;94(1):58-65. DOI: 10.3945/ajcn.110.010132 · PMID: 21543530 [Cohort, n=21]Peter Turnbaugh and Jeffrey Gordon at Washington University compared the gut microbiome of genetically obese mice with that of their lean littermates and transferred it into germ free animals.
The microbiome of the obese animals harvested more energy from the food, and this property was transferable: germ free mice carrying this microbiome put on more body fat. This is a mouse study.
In humans the data are weaker. The principle is plausible, the transfer is not proven.
Turnbaugh PJ et al. Nature. 2006;444(7122):1027-1031. DOI: 10.1038/nature05414 · PMID: 17183312 [In vivo, mouse]How much energy comes from this source in total can only be estimated. One review names up to 10 percent of daily requirement in humans, with clear variation. Ranges between 5 and 15 percent circulate in the literature, so this is an order of magnitude, not an exact number.
On your plate lies not only your food, but also the food of your microbes. They draw energy out of fiber that you could not open up yourself, and at the same time they bind part of it into their own biomass.
No calorie counter knows these fellow eaters. That is why the real yield of the same portion varies between two people.
And now you know the fourth parting point: fermentation in the large intestine.
Calories are raw material, ATP is energy
Now comes the point that occupies me most as a physician. This is no longer about deviations of a few percent, it is about a whole level that does not appear in the calorie calculation at all.
A calorie is not an energy carrier your cell can use directly. Your cell works with ATP. The path there is a biochemical chain, and every step needs tools. These tools are called cofactors, and they are micronutrients.
Thiamine opens the door to the citric acid cycle
For glucose to enter energy production, pyruvate dehydrogenase needs thiamine in its active form. A systematic review puts the requirement at about 0.5 milligrams per 1000 metabolized kilocalories, against a daily recommendation of 1.3 milligrams.
Riboflavin delivers the building block for FAD
The electron transfer flavoprotein works as a hub. It takes electrons from at least 14 flavoenzymes and hands them on to the respiratory chain. For that it carries an FAD molecule, and FAD is built from riboflavin.
Magnesium is what makes ATP usable in the first place
Magnesium is involved in more than 600 enzyme reactions, among them central steps of energy metabolism. Inside the cell, ATP exists as a magnesium complex. Activating thiamine into its working form also needs magnesium.
Iron sits right inside the respiratory chain
Iron is a cofactor of heme and non heme enzymes of the respiratory chain. In deficiency, the formation of heme and of iron sulfur clusters is slowed. Described consequences are fatigue and breathlessness on exertion, even without anemia.
And now the part that is so rarely said out loud.
Calorie counting is macronutrient accounting. It captures protein, fat and carbohydrates. Micronutrients do not appear in this calculation at all. You can hit your calories to within ten and still not know whether your body can build ATP out of them.
And this gap is not randomly distributed. An analysis of the Korean nutrition survey with 16,657 adults showed this: the higher the share of ultra-processed foods, the higher sugar and saturated fat sat, and the lower fiber, minerals and vitamins. A cross section from another population, so an association, not proof.
The same calories, but less of the building blocks it takes to metabolize them. This level is explored by the neighboring spoke From calorie to energy: the cofactors. Why with fats the type can matter more than the amount sits in Omega-3 from plants and animals.
It does not say that you should now go and buy supplements. Whether a cofactor is short in you is shown by a targeted history and targeted diagnostics. The biochemistry is well established, the clinical relevance for the general population is not quantified.
If you want to think further along these lines, it is a good topic for a conversation. Below this article you will find the option to arrange an appointment.
I sometimes say it like this in my consultations: calories are firewood, cofactors are the match and the fireplace. You can fill the room with wood up to the ceiling. Without ignition and without a flue it will not get warm.
When someone describes fatigue while calorie intake is sufficient on paper, this level is worth a look. Clinically I observe that often. Studies that quantify it are rare.
And now you know the fifth parting point: the cofactors, without which raw material does not turn into energy.
Where the opposing view is right
Now it gets uncomfortable, and that is exactly part of the job. There is good science that contradicts this article. I let it stand instead of smoothing it over.
Andrea Buchholz and Dale Schoeller evaluated studies that compared weight loss and energy expenditure on high protein or low carbohydrate diets against low fat diets.
After twelve weeks, weight loss on high protein or low carbohydrate diets was about 2.5 kilograms greater. Neither differences in energy availability nor differences in energy expenditure explained that. Their conclusion: thermodynamically a calorie is a calorie.
For you this means: energy conservation holds. The dispute is about whether the accounting in the calorimeter reflects the accounting in the body.
Buchholz AC, Schoeller DA. Am J Clin Nutr. 2004;79(5):899S-906S. DOI: 10.1093/ajcn/79.5.899S · PMID: 15113737 [Systematic Review]Kevin Hall and Juen Guo summarized 32 controlled feeding studies in which carbohydrate was exchanged isocalorically for fat.
Energy expenditure and fat loss were higher on the lower fat diet, not on the lower carbohydrate one: 26 kilocalories per day and 16 grams of fat per day.
That stands against the larger Ebbeling study from 2018, which found total expenditure higher by 52 kilocalories per day for every 10 percent less carbohydrate. Both works have to be taken seriously in method. I am not going to settle this contradiction here, because I cannot settle it.
Hall KD, Guo J. Gastroenterology. 2017;152(7):1718-1727.e3. DOI: 10.1053/j.gastro.2017.01.052 · PMID: 28193517 [Meta-analysis, k=32] · Ebbeling CB et al. BMJ. 2018;363:k4583. DOI: 10.1136/bmj.k4583 · PMID: 30429127 [RCT, n=164]What this article claims and what it does not
It does not claim that calories do not count. It does not claim that you can lose weight in a surplus. And it does not claim that one macronutrient is superior to another.
It claims this: the unit measures combustion, not processing. Between the value on the packet and what arrives in your mitochondria lie at least five places where something shifts.
Classical nutritional medicine works with the energy balance for good reason. It is robust and it is testable. What an integrative view can add is the question of what happens to that energy afterwards.
Metrics that say less than they appear to say exist elsewhere in medicine too. With cholesterol I have described that in cholesterol and science. There too the number is not wrong, only narrower than it looks.
And now you know why an honest text has to get slower here instead of louder.
What this changes in your everyday life, and what it does not
Maybe you are thinking right now: fine, and what do I do with this in the supermarket?
My answer is unspectacular: you do not have to count differently, only read differently.
Marlou Lasschuijt and colleagues in Wageningen had 18 healthy adults go through four diets: hard unprocessed, hard ultra-processed, soft unprocessed, soft ultra-processed. All of them had the same energy density of 1 kilocalorie per gram.
In the hard conditions the participants ate 571 kilocalories less per day, which is 33 percent. Eating rate there was on average 85 percent slower. The degree of processing on its own did not change the amount.
For you this means: it was not the ultra-processed label that decided, it was how quickly the food could be eaten. 18 people, a single finding, and the authors themselves urge caution.
Lasschuijt M et al. Eur J Nutr. 2023;62(7):2949-2962. DOI: 10.1007/s00394-023-03202-z · PMID: 37452167 [RCT, n=18]A larger study with 106 people fits that picture. Between the hard and the soft version the amount did not differ on average. But the people in the top quarter of eating rate ate twice as much as the bottom quarter. The strongest factor was not the product, it was the speed.
Four directions that follow from all of this
- Read the number as an estimate with a tolerance. Decimal places in tracking apps are a false precision.
- Watch structure, not only quantity. Whole nut instead of nut butter, grain instead of flour, whole fruit instead of juice. The same number, a different availability.
- Notice your eating rate. In the studies it is one of the strongest influences on the amount, and one of the few you can change immediately.
- Think the cofactors in. If you are permanently tired even though energy intake is right on paper, this level belongs in the picture and in a medical conversation.
What I deliberately do not do: hand you a weight loss strategy. The everyday question of whether quality or quantity matters more belongs in the calorie myth: quality instead of quantity. This article stays with the question of what the unit of measurement describes.
The calorie is a good tool with a limited resolution. Like a folding ruler held against a house: the number is right, but it says nothing about whether the roof is watertight.
You do not have to abolish the calorie. You are only allowed to stop treating it as the whole information about your food.
And now you know why two people can eat the same portion and their bodies make two different stories out of it.
Frequently asked questions about calories and metabolism
Are the calorie figures on food packaging accurate at all?
They are properly calculated, but they are an estimate and not a measurement taken on your body. The number comes from the Atwater factors, set values per gram of macronutrient. With whole almonds the measured available energy in a controlled study was about 32 percent below the calculated value, with walnuts about 21 percent. Read the number as an orientation with a tolerance range, not as a bank balance.
Why do almonds have fewer calories than the packet says?
The fat of the almond sits in cell walls made of fiber. Chewing and digestion do not open all of these cells, and part of the fat leaves the body still enclosed. In a controlled study a 28 gram portion of almonds delivered 129 instead of the calculated 168 to 170 kilocalories. Structure is decisive: almond butter reached 6.53 kilocalories per gram, whole raw almonds only 4.42.
What is the thermic effect of food, and how big is it?
Digesting, absorbing, rebuilding and storing cost energy themselves, and that is diet induced thermogenesis. A review places it at 5 to 15 percent of daily turnover for mixed food, with the ranking alcohol, protein, carbohydrate, fat. The individual ranges that circulate, 20 to 30 percent for protein and 0 to 3 percent for fat, are rules of thumb, not values from a measurement study.
Does protein cost the body more energy than carbohydrates?
According to current data yes, and this is one of the better documented points in the field. Reviews and systematic reviews consistently find the highest diet induced thermogenesis for protein, followed by carbohydrates and, by some distance, fat. Part of the protein calories goes into the processing itself. What follows from that in the long run for weight and fat mass is considerably less consistent.
What are the Atwater factors, and why do they still apply today?
Wilbur Atwater burned foods in a bomb calorimeter in the late 19th century. From the heat released he subtracted what came out unused in stool and urine. What remained were about 4 kilocalories per gram of protein and carbohydrate and about 9 per gram of fat. They are average values of a population, not a statement about your individual food.
What is the difference between gross energy and metabolizable energy?
Gross energy is the total heat a food gives off on complete combustion. Metabolizable energy is the part of it that remains after digestion and excretion. In between lie the losses through stool and urine and everything the structure holds back. Measuring it is laborious, which is why these values exist for only a few foods.
Can gut bacteria influence how many calories I take up?
Studies suggest so, but proof in humans is missing. In an inpatient study of 21 people a Firmicutes shift of 20 percent went along with about 150 kilocalories more energy gain per day, though only as an association. In the mouse model, transferring an obesity microbiome was enough to produce more body fat. For humans it holds: plausible, not yet settled.
Does cooked food have more usable calories than raw food?
For meat and starch rich tubers the data point that way. In a study in mice, cooking increased energy gain measurably, more strongly than pounding alone. That is an animal model, not a human finding. The authors derive from it a weakness of food labeling: minimally processed foods are systematically rated too high.
Why do 300 calories of chicken fill you differently than 300 calories of chips?
Because satiety is not a quantity of energy, it is a chain of signals. Protein produces the strongest thermogenesis and the clearest satiety signals among the macronutrients. Texture comes on top: hard foods are eaten more slowly, and in a study with 106 people eating rate was the stronger predictor than the product itself. The same number can leave behind very different states of hunger.
Is calorie counting pointless then?
No, and this article explicitly does not claim that. Thermodynamically a calorie remains a calorie, as one systematic evaluation puts it. Calorie counting can be a useful learning tool because it makes portion sizes visible. It simply has a limited resolution: it captures macronutrients and says nothing about absorption, processing costs, hormonal answer, microbiome and micronutrient density.
Why does the math not add up for me even though I am in a deficit?
There are several unspectacular explanations for this, and none of them is that you are doing something wrong. Label values carry a tolerance, portion sizes are underestimated, and daily expenditure is not a constant. In a randomized study total energy expenditure differed by up to 326 kilocalories per day at identical intake. If weight is your topic, that belongs in a medical conversation.
Which micronutrients does the body need to turn calories into energy?
The biochemistry here is clear. Thiamine is needed for entry into the citric acid cycle, about 0.5 milligrams per 1000 metabolized kilocalories. Riboflavin delivers the building block for FAD, without which a hub of the respiratory chain stands still. Magnesium is involved in more than 600 enzyme reactions, ATP exists as a magnesium complex, and iron sits as a cofactor in the respiratory chain. Whether something is short in you is shown by targeted diagnostics.
The calorie question in the larger picture
Several paths lead onwards from here: to the regulation of hunger and satiety, to energy production in the mitochondria, and to the question of what movement does to your choice of fuel.
Leptin and insulin
How the body regulates weight, beyond the plain balance
Appetite regulation
Understanding hunger and satiety as a signaling system
Mitochondria and exhaustion
When there is enough energy and still nothing arrives
Zone 2 training
What endurance has to do with the choice of fuel
Scientific sources
- Hall KD, Ayuketah A, Brychta R et al. Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake. Cell Metab. 2019;30(1):67-77.e3. DOI: 10.1016/j.cmet.2019.05.008 · PMID: 31105044 [RCT, n=20]
- Novotny JA, Gebauer SK, Baer DJ. Discrepancy between the Atwater factor predicted and empirically measured energy values of almonds in human diets. Am J Clin Nutr. 2012;96(2):296-301. DOI: 10.3945/ajcn.112.035782 · PMID: 22760558 [RCT, n=18]
- Gebauer SK, Novotny JA, Bornhorst GM, Baer DJ. Food processing and structure impact the metabolizable energy of almonds. Food Funct. 2016;7(10):4231-4238. DOI: 10.1039/c6fo01076h · PMID: 27713968 [RCT, n=18]
- Baer DJ, Gebauer SK, Novotny JA. Walnuts Consumed by Healthy Adults Provide Less Available Energy than Predicted by the Atwater Factors. J Nutr. 2016;146(1):9-13. DOI: 10.3945/jn.115.217372 · PMID: 26581681 [RCT, n=18]
- Barr SB, Wright JC. Postprandial energy expenditure in whole-food and processed-food meals: implications for daily energy expenditure. Food Nutr Res. 2010;54:5144. DOI: 10.3402/fnr.v54i0.5144 · PMID: 20613890 [RCT, n=17]
- Karl JP, Meydani M, Barnett JB et al. Substituting whole grains for refined grains in a 6-wk randomized trial favorably affects energy-balance metrics in healthy men and postmenopausal women. Am J Clin Nutr. 2017;105(3):589-599. DOI: 10.3945/ajcn.116.139683 · PMID: 28179223 [RCT, n=81]
- Ebbeling CB, Swain JF, Feldman HA et al. Effects of dietary composition on energy expenditure during weight-loss maintenance. JAMA. 2012;307(24):2627-2634. DOI: 10.1001/jama.2012.6607 · PMID: 22735432 [RCT, n=21]
- Ebbeling CB, Feldman HA, Klein GL et al. Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial. BMJ. 2018;363:k4583. DOI: 10.1136/bmj.k4583 · PMID: 30429127 [RCT, n=164]
- Buchholz AC, Schoeller DA. Is a calorie a calorie? Am J Clin Nutr. 2004;79(5):899S-906S. DOI: 10.1093/ajcn/79.5.899S · PMID: 15113737 [Systematic Review]
- Westerterp KR. Diet induced thermogenesis. Nutr Metab (Lond). 2004;1(1):5. DOI: 10.1186/1743-7075-1-5 · PMID: 15507147 [Mechanism Review]
- Westerterp-Plantenga MS. The significance of protein in food intake and body weight regulation. Curr Opin Clin Nutr Metab Care. 2003;6(6):635-638. DOI: 10.1097/00075197-200311000-00005 · PMID: 14557793 [Mechanism Review]
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