I recently started using MyFitnessPal to try to lose weight and I noticed that a particular beer I had drunk has a tremendous number of calories relative to the number of grams of carbs it contains compared to something like rice or oatmeal. This ended up being a problem for me, because it made it harder for me to hit my macro goals for the day without going over my daily calorie limit.

The nutritional information might be incorrect (this beer isn't from a country that I totally trust the nutritional labels for), or the person who put the nutritional information into MyFitnessPal might have done it incorrectly. I do remember hearing that beer has a lot of carbohydrates, which would seem to go against what I'm saying here.

So: Can a calorie be neither protein, carbohydrate, nor fat?

  • 1
    Nucleic acids (DNA and RNA material) are common in every natural food (Say, leafs of a plant): The body can digest these but I don't know how exactly. Usually their caloric contribution is minimal and have no significant impact on weight.
    – user8225
    Jan 25, 2020 at 6:44

3 Answers 3


Ethanol is caloric and is neither a carbohydrate, protein, or fat.

  • Thanks for the quick answer! Do you know where I can find a list of things that have calories but aren't carbs, proteins, or fat? Jan 24, 2020 at 23:27
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    @NathanWailes IMO this is a good question for Chemistry StackExchange --- if you publish it you are welcome to inform me of it, if you want.
    – user8225
    Jan 25, 2020 at 8:07
  • @JohnDoea Posted here. Jan 26, 2020 at 0:22
  • @NathanWailes thank you, I upvoted.
    – user8225
    Jan 26, 2020 at 0:23
  • How is ethanol excluded from the category of carbohydrates? I note that "Carbohydrates in human nutrition. (FAO Food and Nutrition Paper - 66)" begins chapter 1 with "Carbohydrates are polyhydroxy aldehydes, ketones, alcohols, acids, their simple derivatives and their polymers having linkages of the acetal type."
    – John
    Feb 5, 2020 at 0:13

A calorie is a measure of heat given off by burning a substance.

This article shows the origin of the term in the context of nutrition https://academic.oup.com/jn/article/136/12/2957/4663943

One of the earlier uses of the term in a physiological metabolic context, as apposed to a physics context, was in a paper by a German scientist named J. R. Mayer. The Mayer quote shows an early use of the definition that comes up in nutrition classes.

"When substances endowed with considerable chemical affinity for each other combine chemically, much heat is developed during the process. We shall estimate the quantity of heat thus set free by the number of kilogrammes of water which it would heat 1°C. The quantity of heat necessary to raise 1 kilogramme of water 1 degree is called a unit of heat, Calorie. "

A calorie itself is not something you ingest, and there's no Dietary Reference Intake https://ods.od.nih.gov/Health_Information/Dietary_Reference_Intakes.aspx for it, unlike everything else on the nutrition facts label (maybe that's why it's in separate box).

It's a measure of energy generation, so it depends on the individual process of how it's generated, and I'm not sure if the FDA bases their label's numbers off of cellular metabolic data using digestive enzymes and gut flora, they might use something like a butane torch. It might be a good idea to take the calorie number as a reference point when considering your own metabolism, and not as an exact quantity. Many things can affect someone's metabolism, its efficiency and its rate, at cellular and molecular levels (and above and below probably).

If you're thinking in terms of this definition, anything that causes metabolic reaction that generates heat could be measured as a calorie. Ethanol burns in a lab, but whether or not it generates heat in your body when it's metabolized depends on its metabolic processes https://en.wikipedia.org/wiki/Ethanol_metabolism .

If you wanted to know what substances generate heat in the body in general, the answer might be in the field of bioenergetics https://en.wikipedia.org/wiki/Bioenergetics , but that would include cellular respiration as well as enzymatic processes as the wiki article says, so breathing and processing anything (including your own dead cells thru apoptosis, or any drug you take or xenobiotic substance that enters your body https://www.sciencedirect.com/science/article/pii/S1359644612000359) could be shown to have a caloric value. Nutritionists and food producers are mostly focused on the calories from catabolic metabolism http://www.cte.sfasu.edu/wp-content/uploads/2012/01/2_Principles_of_Digestion_and_Metabolism.html by specifically liver enzymes, of something absorbed through the intestines (different parts of the intestines absorb different things, and not all gets processed catabolically).

The food/nutrition industries' use of "calories" is a weirdly specific definition that presents a narrow view of bioenergetics -- bodies are way more complex and unique!


This is probably a bit of both.

By this, I mean that ethanol does contain calories, 7 kcal per gram of alcohol.

Fat is 9 kcal/g, carbs and protein are 4 kcal/g.

It is also possible that the nutrition label itself is calculated incorrectly, probably by mistake. If you're really bothered by the discrepancy, you could reach out to the company.

Likewise, the info in My Fitness Pal could be incorrectly cited as well. These tools should be used as a guideline, not as concrete fact. If something seems off, you are absolutely correct in questioning it! I've found that in My Fitness Pal, scanning the bar code is typically more accurate than searching for the product. You could also look for a second entry for the product you are searching for and seeing if that one makes more sense.

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