Do calories matter?

Yes. Anyone who tells you otherwise is trying to sell you something.

I could probably just finish this post there, because that’s really all that needs to be said on the topic. But you know me, I’m gonna beat this horse into the ground a little.

I have recently come across a number of people or groups claiming that calories don’t matter, at all. Which is a completely1 delusional2 belief3, showing that they either really don’t understand nutrition, or hope that you don’t.

Now, it is true that not all calories are created equal. Obviously, carbohydrates, proteins, and fats are all handled differently in your body and are used for different purposes, and at various efficiencies. Carbohydrates are used and stored as a source of muscular energy in the form of glycogen, and are the primary energy source your body uses for most day-to-day things, most of the time. Fats are used or stored as triglycerides, or goddamn ass fat as some of us know it. Protein is generally known as the primary building block of muscle, although muscles only contain about 25% protein by mass. It requires a lot more energy to build muscle than the energy contained in the protein however, so you can’t count on ~600 extra calories building a pound of muscle.

If you have spent any time at all consuming information about nutrition or fitness you have probably come across the term “thermic effect of food” or TEF. What this is, is essentially how much work your body has to do to process the calories you are taking in. For fats, it is negligible – something on the order of 1% of the calories you consume are burned to make that energy available to be used for productive things. For carbohydrates, it is a bit higher, but not significantly so – studies have suggested that it ranges from 2%-9% of calories. Protein is significantly higher than either fats or carbohydrates, at roughly 20% TEF. That means that for every 100 calories of protein that you consume, your body is only really able to make use of about 80 of them, as around 20 are consumed in converting the proteins into a form that your body can use. This is one factor in the observed metabolic advantage that high-protein diets appear to have, both in the scientific literature and anecdotally.

So after all that, a calorie is pretty much a calorie. If you are getting a reasonable balance of protein, carbs, and fats, your body will shuttle things around as it needs, and make the magic of our everyday happen.

But what about the people who say that calories don’t matter? Well, I suggest that they stop consuming calories, and tell their body that calories are irrelevant and should just get over it.

If you don’t eat food, or somehow put nutrition in the form of calories and micronutrients into your body, you will die. Thus far, science hasn’t figured a way around this one. Even the silicon valley guys who want to remove food from their lives still consume calories.

Full disclosure: I tried the Soylent thing for a while. It wasn’t terrible, but definitely wasn’t something that I really enjoyed. I like real food too much. I also am not entirely convinced that there aren’t vitamins or other essential micronutrients that we haven’t discovered yet, that we might be missing by not eating whole foods. Anyways, back to your regularly scheduled informational rant.

Are some diets are harder to over-eat on? Absolutely. I had a vegan tell me that it doesn’t matter how many calories you consume, because she could eat as much as she wanted and never get fat while eating only whole foods. Which is completely untrue, and I am actually considering doing a GFH vegan bulk just to prove these assholes wrong. But she does have minor point in that it is very difficult to over-eat when you are on a diet that artificially restricts you to extremely low calorie density foods like green vegetables. However, consume a tub of peanut butter and a gigantic bowl of rice with coconut oil on it every day, and you will get fat. And probably be incredibly miserable, but I think most vegans tend to be, in addition to usually being iron-deficient and thus easily scared away with a large spoon.

Low-carb diets like atkins and south beach and paleo tend to have a perceived metabolic advantage as well, where calories no longer matter. This stems from two main things. One, it is [again] a lot harder to over-eat meals consisting entirely of lean meats and vegetables, at least initially. These foods have a much higher satiety rating when compared to heavily processed junk, which means you feel fuller while consuming less calories. This means that even without counting calories, the vast majority of people will spontaneously consume less food, which means less calories, which means they lose weight! This does not mean that calories don’t matter. The second thing about low-carb diets that makes them feel like magic is the massive initial loss of scale weight that most people see. As we have discussed previously, this is entirely water balance shenanigans, and doesn’t mean that someone lost 35,000 calories of body mass overnight, and thus calories don’t matter.

So, do calories matter? Yes. Are there things you can do to make the calories you do consume more effective, or ways of eating you can employ to make your dieting life easier? Absolutely.

Again, anyone who tells you that calories don’t matter is selling you something or doesn’t have their head screwed on straight. If you eat more whole foods that have more fibre and are more satiating, you will feel fuller and thus be more comfortable eating less food. This is not magic, and does not invalidate the calorie balance hypothesis.

Now go forth, eat mostly real and preferably delicious foods, and be awesome.

  1. Buchholz AC, Schoeller DA. Is a calorie a calorie? Am J Clin Nutr. 2004;79(5):899S–906S.
  2. Schoeller DA. The energy balance equation: looking back and looking forward are two very different views. Nutr Rev. 2009;67(5):249–254. doi:10.1111/j.1753-4887.2009.00197.x.
  3. Schoeller DA, Buchholz AC. Energetics of obesity and weight control: does diet composition matter? J Am Diet Assoc. 2005;105(5 Suppl 1):S24–8. doi:10.1016/j.jada.2005.02.025.

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