Understanding and Explaining the Error of "A Calorie is a Calorie."

[FiddlestixMcWhiskers]

I’m trying to get my head around something. I’m starting to understand how “a calorie is a calorie” is at least misleading and, at worst, totally false. I’m starting to understand that calories from carbohydrates are not quite the same as calories from fats or proteins, but I’m still struggling with a clear understanding of it.

As I understand it, calories don’t really exist; they’re just units of measurement. Just like inches, centimeters, meters and yards don’t really exist in the physical world; they’re just concepts, like numbers. They help us measure and calculate things around us, but they don’t exist themselves; you can’t hold a measurement or a number in your hand.

So, as an illustration to help me get my head around it a bit more, would it be analogous to say that the differences between calories from carbohydrates and calories from fat are similar to the differences between the imperial and metric measuring systems? Since I don’t have a good understanding on the subject of calories myself yet, I haven’t gotten much farther with my illustration; I’m kind of using it as a way for me to understand things.

Is this anywhere close to being a good illustration? Should I continue to pursue this line of thinking or is it a dumb idea for an illustration?

[kib1]

A calorie is a real measurement of heat energy. The trouble with using it in connection with human bodies is that we don’t burn our food. Our digestion is a mechanical and chemical process that has different pathways depending on the molecular structure of the food - there are some things with a caloric value that even pass through undigested at all!

Calories do have some place in nutrition theory. Eventually when food is digested and turned into energy, yes, the results will be different based on whether there is a surplus or a deficit, in other words the caloric content of the accessed energy and in a rough way the food itself does matter. But the molecular structure of it matters as well. How much of the caloric energy is accessed, in what process, and how much bodily energy does it take to do so?

As far as an analogy … If you had a car that had a steam engine and a standard gas motor, you could put wood or coal or gasoline into it. But the process and the results in terms of the car’s performance per joule, or engine buildup, or any other measure of effects of burning the fuel might be significantly different.

[ctviggen]

There was a doctor when I was on Twitter (before it became whatever it is now) who liked to show a picture of 500 calories of sugar and 500 calories of salmon. That was to drive home the point that calories aren’t the same.

If we use 500 calories of pasta versus 500 calories of beef instead, for most (not all) people, that 500 calories of pasta will cause a large blood glucose spike, which will cause all sorts of things to happen: insulin goes up and glucagon down, basically stopping fat burning and putting the body into fat storage mode, just as a beginning. Eating 500 calories of beef will cause some insulin spike, but beef also has fat, which pasta doesn’t. Beef is less likely to turn off fat burning, and there’s no blood sugar spike.

There’s also no real protein in (non-egg-based) pasta, and a much higher amount of protein in beef. Protein typically has a beneficial effect on satiation, and also actually causes the body to expend more energy than do carbs.

The other problem is that we don’t eat “calories”, we eat food. By pretty much any metric, beef beats pasta: protein; iron; a more easily assimilated iron; more B vitamins (unless the pasta is fortified); etc.

I’d guess that for most people, beef will be a lot more satiating than pasta.

Edit: there is a very low fat, very high carb diet that does lessen insulin resistance (think “potato diet”). But it’s unique and, let’s face it, eating really low fat is not fun. Or at least wasn’t for me when I did it.

[OldDoug]

Calories exist.

You’re holding calories in your hand right now. Both within the hand tissue itself, and in the air and water ‘in’ your hand if you cup it. There are molecules there, and they have heat energy.

When it comes to human metabolism, it’s not true (or at least not always true) to state that “a calorie is a calorie,” as simple as that, with nothing else to consider.

Kilograms, pounds, stones, etc., exist - we are talking about physical reality, and heat energy is no different, there - it exists as well. Yes, units of measurements, but in the real world when we eat calories, they are coming in as physical matter. They don’t magically appear and we don’t magically have them disappear.

The proper way to do it is to qualify the statement, to make it more true - “When it comes to human metabolism, there is often more to it than merely just the number of calories.”

That is because that physical matter that we are taking in may have different effects. If it’s a given number of calories from carbohydrates, that may well result in the body sending some of them to storage (our fat/triglycerides), resulting in us gaining mass, tending toward obesity, metabolic syndrome, diabetes, etc.

If we take in the same number of calories from fat and protein, then perhaps less or none will be stored as fat. This is because of hormonal effects and how our digestion and endocrine system work.

“𝑡ℎ𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒𝑠 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 𝑡ℎ𝑒 𝑖𝑚𝑝𝑒𝑟𝑖𝑎𝑙 𝑎𝑛𝑑 𝑚𝑒𝑡𝑟𝑖𝑐 𝑚𝑒𝑎𝑠𝑢𝑟𝑖𝑛𝑔 𝑠𝑦𝑠𝑡𝑒𝑚𝑠”

It’s really not the same as that. The two systems, there, are talking about the exact same things. Just different names and quantities of them.

Usually, the human body has a much higher insulin response to carbohydrates than it does to protein and fat. Insulin tells fat cells to take in glucose from the blood, and make fat (triglycerides) from them.

This is how we gain fat.

When we eat, the calories are definitely there, just as the grams and ounces, etc., are there. The question is where do they go. Do we store them as fat? Do we use them as energy? Do we send them on through and right out as waste?

[CFLBob]

I think @kib1 had a really important point with

A calorie is a real measurement of heat energy. The trouble with using it in connection with human bodies is that we don’t burn our food.

As well as @OldDoug with

The proper way to do it is to qualify the statement, to make it more true - “When it comes to human metabolism, there is often more to it than merely just the number of calories.”

That is because that physical matter that we are taking in may have different effects. If it’s a given number of calories from carbohydrates, that may well result in the body sending some of them to storage (our fat/triglycerides), resulting in us gaining mass, tending toward obesity, metabolic syndrome, diabetes, etc.

Calories are measured by burning food in a bomb calorimeter and measuring the energy released. Simply, our bodies are considerably more complicated than a calorimeter. Some of the things we eat can’t be easily digested in the chemical processes we live on so some of those calories are just shoved in the waste stream. “Fiber” is famously cited as indigestible - but there are many different kinds and it’s more like a continuum from somewhat digestible to not all.

There’s lots of evidence down this subject that will really upset your mind. There’s no proof that there’s 3500 calories per pound - (eat 3500 more than you burn and you gain a pound; eat 3500 less than you burn and you lose a pound). Researcher Dr. Zoe Harcombe from the UK has tried to find the origin of that “fact” and none of the UK national agencies that are responsible for dietary and health advice had a reference to an experiment that proved that number. The best they could do was trace it to the advice of someone who published it as their own conclusion in the early 1900s. Video here

[FiddlestixMcWhiskers]

Researcher Dr. Zoe Harcombe from the UK has tried to find the origin of that “fact” and none of the UK national agencies that are responsible for dietary and health advice had a reference to an experiment that proved that number. The best they could do was trace it to the advice of someone who published it as their own conclusion in the early 1900s. Video here

I’m not usually a fan of female lecturers, but, I’m about 2:30 into the video and, so far, I really like this woman.

[CFLBob]

She’s got a pretty good fan base among keto researchers and us keto followers, so welcome to the club!

[OldDoug]

Calories are measured by burning food in a bomb calorimeter and measuring the energy released. Simply, our bodies are considerably more complicated than a calorimeter. Some of the things we eat can’t be easily digested in the chemical processes we live on so some of those calories are just shoved in the waste stream. “Fiber” is famously cited as indigestible - but there are many different kinds and it’s more like a continuum from somewhat digestible to not all.

True, Bob, but our bodies are usually very efficient at getting the energy out, frustratingly so for many of us.

People can live in whole-room calorimeters where everything is kept track of, even the molecules they breathe in and out. The math of everything works out quite well.

There’s lots of evidence down this subject that will really upset your mind. There’s no proof that there’s 3500 calories per pound - (eat 3500 more than you burn and you gain a pound; eat 3500 less than you burn and you lose a pound). Researcher Dr. Zoe Harcombe from the UK has tried to find the origin of that “fact” and none of the UK national agencies that are responsible for dietary and health advice had a reference to an experiment that proved that number. The best they could do was trace it to the advice of someone who published it as their own conclusion in the early 1900s.

The oft-quoted deal for calories in fat is 9 per gram. 454 grams in a pound, so that would be 4086, already in the ballpark.

We’re not perfectly efficient, so the end result will be even closer to 3500, as far as running a net deficit. If we’re burning fat, and if we burn 3500 more calories than we take it, its really going to be close to 1 lb. of stored fat that we lost.

And - stored human fat has some water in it, so if we correct for that, and for the exact caloric content in our particular (human) mix of triglycerides as we store fat, it ends up so close to 3500 that I doubt that any of us has no problems that are considerably more pressing.

I did the math, there, once - and it’s likely somewhere on this forum. I think I ended up at 3,447 calories equating to a pound of human stored fat, water included. Not that it would be that way for absolutely everyone - there are genetic differences in the ratios of the various triglycerides that humans store, and the water portion of stored fat may vary some, too. But I still have never seen anything that says the difference, in the end, from 3500 calories, will be significant.

[SomeGuy]

I’m not usually a fan of female lecturers, but, I’m about 2:30 into the video and, so far, I really like this woman.

Zoe is awesome. If you are “not usually a fan of female lecturers” you’re sadly missing out on many of the very best.

As for calories:
There are roughly 2 calories in a shot of vodka. As such, a day’s need of about 2000 calories can be met simply by drinking 1000 shots.

The math is as simple as is the calorie in/calorie out model.

[scaperdude]

So, as an illustration to help me get my head around it a bit more, would it be analogous to say that the differences between calories from carbohydrates and calories from fat are similar to the differences between the imperial and metric measuring systems?

No not really. A calorie is the measuring system. You can’t change it to a different measuring system and call it a calorie. As has been indicated, a calorie is simply measuring a unit of energy, except it is food. It is like comparing a unit of energy in diesel to a unit of energy in gasoline. The things is like automobile engines, our bodies burn units of energy from different sources at different efficiencies and tolerances. That is what makes the calorie is a calorie trope a “lie.” When it comes to the way a calorie gets utilized by the body it DOES matter the source. If you try to burn diesel in a gasoline engine, you aren’t going to get too far. A calorie from a soda pop is going to get burned much differently than a calorie from a steak. First, it takes much more energy to get that calorie out of the steak, whereas it takes almost none to get the energy out of sugary soda pop. Secondly, the calorie from a soda pop is going to spike insulin much more than the calorie from a steak - like twice as much. Insulin is a hormone which drives how the body is going to utilize that energy. Is it going to get stored as fat or glycogen? Or is it going to go towards rebuilding cells? Those are very different things. The first will promote weight gain and metabolic disease when repeated on a large scale.

Those are probably the two main reasons that “a calorie is a calorie” is not true when it comes to bodily health.

[Shinita]

differences between calories from carbohydrates and calories from fat are similar to the differences between the imperial and metric measuring systems?

Not at all, the latter is used for the exact same things, it’s just a different number and there is even an exact formula.

If you had a car that had a steam engine and a standard gas motor, you could put wood or coal or gasoline into it.

Yes, this sounds good to me! Good analogy as much as I can tell! The body/car simply does different things with different materials!

a picture of 500 calories of sugar and 500 calories of salmon. That was to drive home the point that calories aren’t the same.

How does it make any sense? It just shows it LOOKS different, it has nothing to do with what it does in the body!
I can show pictures about 500 kcal pork and 500 kcal pork, even with the same macros, not looking similar at all! Photos are usually used to show “look how much you can eat if you choose this instead of that” and even that is horrible to me as I am no volume eater (not even in a mental way, I mean when one see little food and decides it can’t be enough for a meal. if it does the job, it’s enough) and dense food is way better for my satiation (the right dense food, that is).

The other problem is that we don’t eat “calories”, we eat food.

We eat both I definitely need to eat calories, lots of it. There is no other way to get energy, satiation and satisfaction… But yep, we eat food, way more complex than just some calories! Even the macros are a gross simplification, it’s not enough if they are right, the food must be right too. (Maybe not for everyone.)

I’d guess that for most people, beef will be a lot more satiating than pasta.

Indeed. I don’t even understand the existence of people who can get satiated by a bunch of carbs and little else and they do exist. Wow.
Usually, beef is among the top satiating items while pasta is quite bad. Simple sugar is even worse. Macro is one thing but normal people feel if they had something nutritious… Right? They should. It’s not for each and every meal, necessarily. My SO can eat a super carby, very low protein meal and it satiates him for very long - but he does need protein and fat in his later meals. I consider this normal, our body tells us what we need, at least vaguely. I don’t need to track to eat enough protein and fat, I just eventually get hungry with a strong desire for them. I even have meat desire now (odd as I mostly ate vegetarian in my life and it was no problem).
It is broken in some people, that’s tough.

There are roughly 2 calories in a shot of vodka.

My database say 112 kcal and well, we know alcohol has a few kcal/g and a shot of vodka has about 20g alcohol so it sounds legit.
Not like it matters to me. I never track my strong spirits, it’s negligible calories But it’s because I never drink a whole shot.

As for calories… They are still pretty great at predicting my bodyweight changes. Except when I overeat as I just maintain then (with my current body, sadly I can gain if I am slimmer). Even better for my SO as he lack this ability to maintain (but he is slimmer too. still, his body quickly responds to dietary and exercise changes). It totally works for some people and gives some vague guideline for others. Knowing the guessed calorie content of our food may not help us to get a better figure or health but it does give us some info, useful or not (if it’s very tiny, we definitely don’t eat right, we can tell this much). We just should be aware that the human body is way more complex. Blind trusting in guessed calories (I mean, measuring everything and getting a number in the end. it’s not the real number, it’s always a guess) can be tragic, I saw some heart-wrenching examples.

If we want to go to the right direction, we should focus on health anyway… Our food is the key (and sometimes timing), not calories. Calories should be right too but it’s not so easy to say what that exactly means and anyway, I couldn’t stop when hungry or needing protein. Using the right food, things probably fall into place. If not, some research or experiment should help, not enforcing some calorie ideals.
Not like enforcing low-carb is good for everyone. (Some) people can lose fat and stay slim on high-carb perfectly fine, they still can be health-conscious and healthy if their actual diet fits them. Raising insulin doesn’t necessarily result in fat gain, just like eating keto doesn’t necessarily result in fat loss in overweight/obese individuals (and probably some manage to gain fat on keto too as it wouldn’t make sense if it wasn’t possible. overeating on keto is very easy for me, I know that but overeating and gaining are two things. with my eating abilities and someone else’s body, though… and if someone NEEDS gaining fat, that’s another matter entirely, why would keto keep the body to get healthier?).
It’s a bit sad I can’t know how much fat my body stored as fat during my life, I would be curious to know. I gained fat as I overate fat/calories, that’s sure (carbs are the root though, they triggered the whole mess but I couldn’t have happened without all the fat calories) but I did eat much carbs too and I never could gain quickly so it’s entirely possible that my body used the fat and stored the carbs. Not like it matters, really. I don’t even care if my body stores fat after a meal (it seems to matter a lot to some people for some reason). It can store and take out next day, main thing they shouldn’t stay in

[kib1]

There’s another important thought when it comes to calories. The body adjusts. It adjusts metabolism, it adjusts appetite, and it adjusts activity level.

This is a funny little thought experiment I did back a bit. There used to be many diets extolling the virtue of cutting out a single element. For example, that if you cut out 100 calories of Coca-Cola a day, that would be a deficit of 36,500 calories a year, or approximately 10 pounds lost. Easy peasy! So tell me, using this wonderful math, after 30 years, how much would you weigh? (I’d be in the realm of 200 lbs of anti-matter at that point. ). And if you were to add a 100 calorie soda every day?

Clearly, the body relies on more than a simple mathematical formula based on caloric energy! While activity is an external variable, slowed metabolism or increased appetite is entirely the body choosing to do something differently with the calories it receives. For this reason as well, a calorie is not a calorie.

[CFLBob]

The body adjusts. It adjusts metabolism, it adjusts appetite, and it adjusts activity level.

This! We very adaptable.

I noticed this when I was right out of high school, when my folks’ GP put me on a low calorie diet. That was long before I took my junior year class in “feedback and control systems” and didn’t have any words for what seemed to be going on.

[OldDoug]

Those are probably the two main reasons that “a calorie is a calorie” is not true when it comes to bodily health.

Indeed, and there, it’s also true that a gram is not a gram, a pound is not a pound, a milliliter is not a milliliter, a joule is not a joule, etc. From a physical point of view, it’s surprising that there is so much consternation about it.

[PaulL]

So, as an illustration to help me get my head around it a bit more, would it be analogous to say that the differences between calories from carbohydrates and calories from fat are similar to the differences between the imperial and metric measuring systems?

No, the analogy works better for (kilo)calories and (kilo)joules.

The difference is in the effect the food has on our system. Sugar, starches, and grains raise our serum glucose, and hence our serum insulin, and hence our blood pressure and many other problems. They also inhibit ketogenesis and fatty acid metabolism.

Meat and fat, on the other hand, do not raise serum glucose, hence do not raise serum insulin, hence do not raise blood pressure or cause those many other problems, and they inhibit neither ketogenesis nor fatty acid metabolism.

Another useful comparison is that, at 4 (k)cal/gram, a (kilo)calorie of carbohydrate weighs 0.25 g, which implies that 100 (k)cal of carbohydrate weighs 25 g.

On the other hand, at 9 (k)cal/gram, a (kilo)calorie of fat weighs 0.11 g, which implies that 100 (k)cal of fat weighs 11.11 g. So if mass in is affecting our weight, I know which of the two to choose!

NOTE: 1 calorie is a very small amount of energy. Food is measured in kilocalories, even though we leave the “kilo-” off for convenience’ sake. Please bear that in mind.

NOTE ALSO: A calorie is defined as the amount of heat required to raise the temperature of 1 cubic centimetre (1 mL) of water 1° Celsius. Therefore, a kilocalorie is the amount of heat required to raise the temperature of 1 litre of water 1° C. The figures of 4 kcal/g for carbohydrate and protein and 9 kcal/g for fat are only approximations, calculated by burning various foodstuffs in bomb calorimeters, measuring the heat increase, and averaging the results. The exact caloric value of a specific foodstuff is quite variable, especially in the case of fats. Furthermore, the relationship between that heat from combustion and the energy yield of foods in terms of ATP molecules is never discussed. The body does not use heat energy per se to fuel itself, but rather the electrical potential of reducing ATP into ADP.

A century and a half ago, when measuring the heat yielded by burning food was all scientists could measure, kilocalories were used as a rough guide to quantities of food. Insulin was not discovered until 1923, and serum insulin was not measurable until the 1960’s.

[PaulL]

I’m not usually a fan of female lecturers, but, I’m about 2:30 into the video and, so far, I really like this woman.

She knows what she’s talking about, and has the mathematics and statistics to back it up. Other women lecturers you may find yourself respecting are Nina Teicholz, Ph.D., and Georgia Ede, M.D.

[ctviggen]

If you want to drive yourself really crazy, look into EBM (energy balance model) versus CIM (carbohydrate-insulin model).

When I went on Atkins multiple times, then finally on January 1, 2014, I noted a complete lack of hunger at certain points, particularly (initially) at lunch. I wasn’t hungry. For my transition after January 1, 2014, I lost quite a bit of weight, while reducing my exercise and eating as much as I wanted. I wasn’t hungry.

To me, the CIM is better to explain this than is the EBM.

I haven’t found a model that fits everything I observe, though. The CIM is primarily based on insulin, but I think it’s missing other hormones. For instance, if I eat, I get hungry. Why? Seems to me there is more than insulin involved.

[SomeGuy]

If it hasn’t been noted in this thread, it’s certainly been covered elsewhere…

A (kilo)calorie is measured as the amount of heat produced into surrounding water when a sample food substance (usually 1 gram) is fully combusted in a lab (i.e., incinerated and goes up in flames).

If this were how your body reacted to food, you’d be dead by now.

[OldDoug]

When it comes to the way a calorie gets utilized by the body it DOES matter the source. If you try to burn diesel in a gasoline engine, you aren’t going to get too far. A calorie from a soda pop is going to get burned much differently than a calorie from a steak. First, it takes much more energy to get that calorie out of the steak, whereas it takes almost none to get the energy out of sugary soda pop. Secondly, the calorie from a soda pop is going to spike insulin much more than the calorie from a steak - like twice as much. Insulin is a hormone which drives how the body is going to utilize that energy. Is it going to get stored as fat or glycogen?

I like the diesel/gasoline example - that makes total sense. Same amount of calories or joules or BTUs of energy in both cases, but yes - the gas engine will produce different results with the diesel.

As a practical matter, it’s worse to go the other way, fill the tank on a diesel vehicle with gasoline. My employer had at least two people do that, over the years. One was on his second tank of gas when the engine quit with fairly catastrophic damage.

That is what makes the calorie is a calorie trope a “lie.”

Here is where I disagree. First, some people do fine on very high carbohydrate diets, and/or don’t gain weight, get sick, etc., to begin with.

Saying, in effect that “a unit of measurement is a unit of measurement” - how can that be wrong?

I think it would be correct to say that “sometimes (or often) the type of calories, etc., do really matter.”

Or, “a calorie of fat, or of protein, or of carbohydrates, will have demonstrably different effects in many people.”

But on a rational, physical level, to challenge the unit of measurement itself is meaningless.

Saying “a calorie is a calorie” is not pronouncing on what type of calories are involved, so to ‘shoot the messenger,’ so to speak, is irrational - it’s people going back, after the parameters of the discussion have changed, and cruelly assaulting the original, innocent statement in a momentous travesty of justice.

Additionally, when we are talking about calories that people eat, then at least let us have the information about what happens, i.e. where they go. If we know both the In and the Out, then we have a good bit of knowledge right there.

I think the discussion itself is really just philosophical, and that people with different desires will end up with different opinions on it.

[lfod14]

I’m trying to get my head around something. I’m starting to understand how “a calorie is a calorie” is at least misleading and, at worst, totally false.

Well, they are. Problem isn’t Calories, it’s people misapplying them to a very complex thing, which is our metabolism. But even with that said, they’re the best thing we have to measure by. Not perfect, but literally nothing we test medically is, but people ignore that, because calories have become a talking point.

As I understand it, calories don’t really exist; they’re just units of measurement. Just like inches, centimeters, meters and yards don’t really exist in the physical world; they’re just concepts, like numbers. They help us measure and calculate things around us, but they don’t exist themselves; you can’t hold a measurement or a number in your hand.

By that logic nothing exists… hell of a rabbit hole. Does weight, height, blood pressure exist? People test cholesterol, calcium plaque, do those not exist? The world and everything in it exists regardless of us coming up with names for it all, or methods for measurement. We came up with all that because if you don’t, you’re just ignoring everything.

So, as an illustration to help me get my head around it a bit more, would it be analogous to say that the differences between calories from carbohydrates and calories from fat are similar to the differences between the imperial and metric measuring systems?

Not really, because calories are the same either way, that’s the false connection, the effect can be different, but a calorie is a calorie. To further add to it, even that has huge wiggle room, even with things popular in keto circles like Glycemic index/load. The glycemic load for one person isn’t the same for another, many times not even in the same ballpark.

Is this anywhere close to being a good illustration? Should I continue to pursue this line of thinking or is it a dumb idea for an illustration?

That’s ultimately your call, but the road you’re on doesn’t have an end. Makes a lot more sense (to me) to take what we have, and use it all to figure yourself out, and use that to optimize.

I read your question, and answered, because at some point we invented an alphabet, and letters, and then made up sounds that they made, seems to be working out pretty well!