Is a calorie a calorie which is a calorie?

My wife who IMHO embraces naturalistic fallacies was showing my son something on her phone about an otherwise healthy man who ate right and exercised regularly and decided that he would see what happened if he drank 10 cokes a day for 30 days. Not particularly surprisingly, he gained 23 lbs. I pointed out that you would expect that if you consumed an additional 2000 calories a day and changed nothing else, but she claimed that there was something special about the sugar, stating that “a calorie is not a calorie is not a calorie”. I know better than to get into an argument about, but this contradicts what I (and she, for that matter) heard Dean Adell say. I also like to think that I am willing to weigh evidence fairly. Is there new research which says that fat calories are better that sugar calories are worse that protein calories, etc.?

I am aware that if you ate or drank nothing else, 10 cokes a day would cause you to die of malnutrition, but I submit that that diet would not kill you in 30 days, nor would it make you fat if your base metabolic rate is about the calorie count of 10 cokes.

Am I full of shit?


Yes. It goes against EVERYTHING we’ve been taught, but we do metabolize fats differently than sugars. From what I’ve read, it’s not new research, just that it’s being looked at again more seriously because of the “epidemic” of obesity in the U.S.

On a personal note, I was encouraged to stuff myself as a kid, starting from the clean your plate campaign by my parents when I was little, to them watching me eat three stuffed game hens in one meal when I was a teenager. Needless to say I’ve always struggled with my weight, bordeline obese but heading constantly up and up even though as an adult I’ve been cutting out things like salt, sugar, sodas and processed foods. Even still, my weight has been going steadily up until I complained about it to someone who pointed me at the paleo/primal diet theories. I was complaining bitterly that the only way to get control of my weight was to starve myself.

I’ve never been a fad diet person (as you can guess from the previous paragraph) so read the information with a very skeptical eye. But it sounded rational, so I started it this past November. I track my weight in Excel with a line chart. Last year the line was a steady trend up, since November it’s been a steady trend DOWN. The only change I’ve made to my diet was to cut out most carbohydrates and glutens. Not entirely; I’ll eat a wrap in a tortilla instead of a sandwich with bread, for example. But the very large percentage of what I eat now is meat and vegetables.

And 70% chocolate. Life’s not worth living without chocolate!

In what way and what difference does it make vis-a-vis the original question? I would say that you are losing weight because you are eating fewer calories. Are you in fact eating the same number of calories you were eating before? I am prepared to believe that for some people, eating fewer carbs causes them to want to eat less. (For me, in the words of Louis C.K., “I don’t stop eating because I am full. I stop eating because I hate myself.”) :smiley:


The calorie content in food is measure by burning the food in a controlled oven then measuring how much extra energy is produced. However your body doesn’t burn food that way. Your body can extract nearly 100% of the calories in table sugar and sodas. On the other hand, things like almonds are very hard to extract all the calorie content as the calories are trapped in cells. You need to chew and chew almonds, and many other nuts and vegetables, to extract most of the calories. Most of us will just swallow the almonds before they are totally chewed.

Also how a food is prepared can make a difference. A raw potato has little in the way of calories. However if you bake the potato, the calorie content goes way up. The same goes for many other vegetables and, to a lessor extent, meats. For fruits it’s the ripeness that often increases the sugar in the banana, for instance, and therefore the calorie content.

Before, to try to lose weight I would eat less and feel hungry all the time. Now that I’m eating meat and vegetables, I’m not hungry all the time. I do think I’m eating less because of that, and it absolutely is contributing to my weight loss. I think it’s because avoiding the sugars and starches means that I’m no longer riding the blood sugar rollercoaster. Meat, vegetables and snacking on nuts gives me more even blood sugar levels throughout the day.

The book I read, and I’m trying like heck to remember the title because it’s a good one out of an ocean of bullshit, explained it better. But let me give it a try: sugars (and simple carbs that are converted to sugars) trigger an insulin response which makes your body store them away in fat cells before they’re metabolized. But calories from proteins are metabolized first and if there’s any extra left over, then THAT is stored in fat cells. So when you eat a lot of bread/cake/cookies/etc that sugar instantly gets packed into fat cells, triggers an insulin response which makes you crash and then feel hungry again too soon, so you eat more when you don’t really need more calories.

A calorie is a calorie, but our bodies metabolize different compounds differently. Not all calories trigger the insulin response the same way. That’s the difference in a tiny nutshell. I’ll keep trying to remember the title of that book…
… Ah, it’s this one. The title does sound like it’s just another fad diet theory but it’s actually pretty sound.

So we excrete many of the calories in non-sweet foods? What percentages?



who said that?

JerrySTL said that.

But I want to know the citation your book uses to justify that (not saying it’s wrong, but that book is not exactly peer-reviewed).


I think you misunderstood him. He’s talking about the difference between sugars and fiber. You have to chew fiberous things quite a lot in order to digest them, he used the example of almonds.

And yes, nondigestible fiber is excreted. But that’s not a large percentage of your average diet unless you go around eating hay.

Also, the book I cited doesn’t comment really on what JerrySTL is talking about. It talks mostly about the difference between metabolizing sugars and proteins, and doesn’t talk about fiber much.

But gluten *is *protein. I can see cutting down on carbs, but I don’t see any advantage to switching to gluten-free products (unless you have an allergy or celiac disease). I’d think it would be a drawback, since gluten-free products contain no protein, and therefore a higher percentage of carbs.

Of course a calorie is a calorie.

However, as mentioned earlier, different substances are absorbed and used by the body in different ways, so two foods with the same calorie content will not lead to the same amount of weight gain.

So yes, you can second guess calories, but in anything remotely resembling a human diet (i.e., not made up of cellulose or 50+ % protein) it’s not going to make a huge difference: maybe 2000 kilocalories from cola is going to make you gain the same amount of weight as 3000 kilocalories from almonds, but does it really matter? You should no more be drinking five liters of cola a day than you should be eating half a kilo of almonds a day.

With all due respect, I don’t think I misunderstood him at all. I understand that you can’t digest indigestible things, but we also have powerful acid in our stomachs that do a pretty good job of reducing what we swallow into goop. It sounded to me like he was saying that most of the calories are encapsulated inside of indigestible structures, and therefore the calories per gram listed for a particular food is inaccurate because some portion is not bioavailable because we can’t be bothered to chew our food. I don’t think that’s true, but I am no expert. If I am wrong, please enlighten me.


Agreed that you should not be drinking that much soda or eating that many almonds. However, the claim that 2000 calories worth of soda is equal to 3000 calories of almonds (or 2000 calories worth for that matter) has not been established in this thread.


There is a difference between “calorie” and “nutrient”. The root word of “calorie” is “calor”, which means “heat”. Indeed, calorie is about heat energy. Nutrient nourishes. A high-calorie food with little nutrients is called “empty calories” and an individual may become malnourished, if that is whatever the person eats regularly.

Fat has 9 kcal/gram.
Alcohol has 7 kcal/gram.
Protein has 4 kcal/gram.
Carbohydrate has 4 kcal/gram.

In terms of energy release, fat is packed with calories, while proteins and carbs are less calorie-dense. They are all the same calories, though, but they go through different metabolic pathways.

Right. (And I made up that 3000 number to make a point.)

There are even more factors that haven’t been mentioned yet, in addition to bioavailability which in part depends on chewing. X calories of one food will make you feel satiated for many hours, while X calories of another food will leave you hungry again in half the time. Absorption of macronutrients also depends on gut flora, and people have different size glycogen stores in the liver and muscles, which makes them react differently to incidental high glucose intake.

Y’ever look at your poop after a particularly good salad? There’s so much…stuff in there. Recognizable stuff, like leaves of lettuce and bits of carrot and corn. Whatever you can see could be taken out of your poop, dried a bit and burned in a crucible to release more calories. So those are calories that your body didn’t actually get out of the food.

Y’ever look at your poop after a great steak and fries? Looks like poop. Your body is much better at getting the calories out of there than it is out of most vegetables.

So, yes, while the party line is still “a calorie is a calorie”, a little direct observation shows this to be blatantly false on the macro scale, and that’s not even beginning to discuss insulin, fat storage and sugar metabolism on the micro scale.

The highlighted piece is a completely different effect than whether the calories can be extracted. Feeling hungry encourage more caloric intake and you identify that you are probably eating less.

Back to the OP, I just found this. There’s a comment from a Doctor Yavari (Endocrinologist) that has metabolism of fats being 95% efficient while proteins are 70% efficient. He pops up here saying Carbs are 85% efficient. That neglects food specific differences like the raw potatoes that I’d never heard of (and I can’t cut up a potato without significant chunks of it being eaten raw…who knew that was a weight loss plan!) Since that’s all one guy as a cite I’d be interested in possible rebuttal.

Still his numbers seem to undercutthe notion that fats are better for weight loss on a strict calories available standard. Fats are calorically dense and those calories are efficiently used. In fact they are the most efficiently used by the body. His dietary suggestions seem to come down to other effects, for which JcWoman is anecdotal evidence.

On first look it seems like you are closer to the facts than your wife. A calorie in is not strictly a calorie available; there’s a big but though. Nominal carb calories seem to be less available for use than fat; even if sugars are more available than more complex carbs it would be hard to beat the 95% fat efficiency by much. The case of sugar calories counting more than fat doesn’t seem to fly on first glance. Admittedly that’s citing one guy without the base line reasearch. Still he’s a guy that is advocating dietary changes she’s probably agree with just for different reasons.

Ten 12oz cans of Coke a day and I lose weight. I need around 2200 a day to maintain and that’s only around 1400 calories. I’m losing a lb every couple days on the coke diet. I should write a book…:smiley:

Not all gluten-free products contain carbs. Meat, for instance.

A calorie is a calorie and the human body’s response to a calorie in one form is different than to another. This is hardly new. One basic part of this is described as the thermic effect of food (TEF). It takes energy to digest and protein takes much more energy to digest than does carbohydrate which takes more than fat, although the nature of the whole food and precise fat or protein matters too.

Some foods tend to not have their calories completely absorbed also. Nuts are a great illustrative case. Not only does the high protein content have a high TEF but chewed nuts end up passing a fair amount of the fat along in the stool.

Lastly the type of calories impacts where the excess energy gets stored. Lots of added processed sugar far in excess of need tends to encourage liver and central fat deposition - the sort associated with the worst outcomes.

The high cola diet would be associated with loss of fat free mass and even if weight ended up unchanged there would he a higher body fat percent at the end.

By the way none of that addresses the impact on satiety and satiation - that is how easy of difficult it is to consume just that many calories.

Also just doing the math, no 3000 calories of almonds are not worth 2000 calories of energy intake from Coke. 2300 to 2400 though is pretty likely accurate (differences from energy lost in stool, estimated to be 17%, and from differential TEF, about 20% difference).