CICO is a useless tautology

"Caloric deficit" literally means "fat loss"

Tilting at CICO mills

I’ve wasted spent a lot of time recently battling CICO-bots on Twitter. Having written down my thoughts on caloric deficits and Calories In, Calories Out before, apparently that’s still not enough to get the point across.

So let me say it again:

1. CICO is a useless tautology.

2. Calories are not causal, they are a descriptive accounting entity.

3. Constantly yelling “CICO! Deficit!” is an obstacle to progress.

Calories are a measure of energy

Technically, calories are measured by burning a given substrate in a bomb calorimeter. That’s of course not how it works in our body, but let’s assume for the sake of argument that the stored chemical energy in the food we eat is accurately described by “calories.”

Note how the “calories” of a given food are the SUM of the stored chemical energy in it. For example, if we eat a pound of ribeye steak, we could argue that the 85g fat, 0g carbs, and 112g protein (https://www.nutritionix.com/food/ribeye-steaks) add up to 85 * 9 + 0 * 4 + 112 * 4 = 1,213kcal.

Of course there aren’t really 1,213 “calories” in the steak. Calories don’t exist, they are an abstract accounting entity that we use to summarize the estimated chemical energy in fat, carbs, and protein. Just like there aren’t any dollars in your house or car, yet we estimate the price of a house or a car to come up with your net worth.

Similarly, the “calories” inside our body are the SUM of the stored chemical energy in our body. Presumably, if we took all the body fat and all the glucose and all the protein out of your body and burned it in a bomb calorimeter, we’d come up with a total number of calories that your body contained at the time. Eww, gross! You’d be super dead. Let’s not do that.

Instead, let me illustrate with a pretty picture:

Oh hey, it’s our friend Bob from The Slightly Complicated Theory of Obesity!

But what’s that? We magically have X-ray vision of Bob and can identify some key components that pertain to the question at hand. What a coincidence.

1. At the top is where Bob puts the food when he’s eating. Presumably, that’s the first potential “Calories In” spot as the “calories” in the food literally go “in”to Bob here.

2. It takes a while to do the whole digestion thing, and it’s debatable if undigested food is already “in” in the CICO sense - are we counting the physical boundaries of the body, or do the “calories” (=fatty acids, amino acids, glucose, ..) have to enter the metabolism?

3. Like many oval-shaped people, Bob carries around quite a bit of fat mass. 100lbs might seem like a lot, but I had way more on me not too long ago. I still have about 85lbs of fat mass now! If we math real quick, 100lbs * 3,500kcal/lb = 350,000kcal from body fat. Holy canoli, Bob is a very energetic man!

4. As mentioned in the post about water weight and blatantly copied off Wikipedia on Glycogen, the body can store about 1lb of glycogen at any given time. 1/4 of that is stored in the liver, the rest in muscle tissue. Only the liver glycogen can be released back into the blood stream, whereas muscle glycogen can only be used up by that muscle. Doesn’t matter for our purposes, BECAUSE WE’RE BURNING YOU IN A BOMB CALORIMETER! Just kidding, we’re not. Now I don’t know how many “calories” glycogen has per gram, but let’s just assume it’s similar to glucose, therefore 4kcal/g. That means an adult human, like Bob, can store up to 454g * 4kcal/g = 1,816kcal in the form of glycogen.

5. Finally, there are about 4g of glucose in the blood stream of an adult human at any given time, replenished on demand by said liver glycogen. 4g * 4kcal/g = 16kcal from blood glucose. Nice touch.

6. I’m not counting the stored chemical energy from protein, because ostensibly the goal is fat loss and not protein loss. If you want to lose muscle, have you tried Ozempic? Fat, glycogen, and glucose are the day-to-day fuels of the body. You can technically burn your muscle, but it’s an inefficient and inadvisable process, like burning your furniture for heat. Emergency only!

7. There’s also a TMI part that I didn’t draw because I don’t like the color brown. Conceivably, food “calories” could leave your body this way, too. But presumably you’re not on the diarrhea diet either.

To summarize, here’s the “caloric” composition of Bob, or at least of the parts usually involved in his metabolism, for fat loss:

• 350,000kcal of body fat, for 99.47%

• 1,816kcal of glycogen, for 0.51%

• 16kcal from glucose, for 0.00005%

• 351,832kcal in total

So as we can see, over 99% of “calories” in Bob’s body are fat. The other reservoirs (glucose and glycogen storage) are extremely limited in comparison, making up just a little over 1/2 percent of available capacity.

Hence, “calories in > calories out” quite literally means “fat stored.” Unless we’re counting undigested food, vomiting, and “calories” lost through the TMI route, or topping up our extremely small glycogen reserves.

Calories are not causal, they are descriptive

As we can see, “excess calories” do not cause fat accumulation, and a “caloric deficit” doesn’t cause fat loss. They are descriptive accounting entries that merely describe what has happened.

Just like, when you say you “put some money into your house” we know you didn’t really put a bunch of duffel bags full of $100 notes in the basement. You can repair the plumbing, fix the roof, or put a new kitchen in. That might raise the price of the house. But any increased dollar amount ascribed to the house is merely an accounting description of those processes and their effects, it’s not causal.

You could use the same accounting terminology and describe a party as “people in > people out.” But “increasing people intake” isn’t a way to have a party, it involves writing invitations or calling people on the phone, or whatever kids do these days (TikTok?). “Increasing people intake” is nothing but a more abstract description of these actual, causal steps you took.

Tautologies are tautological

A tautology is an assertion that is always true.

Clearly, CICO is always true. How would you even design an experiment to falsify it?

If someone lost fat, “he was in a deficit!” If he didn’t lose any fat, he “clearly wasn’t in a deficit!”

Yes, since fat loss is literally the same as caloric deficit. It would be bizarre to expect otherwise, like expecting more people to leave a party than arrive without the number of attendants going down.

If you talk to CICO-bots and disagree with them, they typically immediately claim that you’re trying to “break the laws of physics” - a tell-tale sign that they believe in a tautology.

CICO isn’t wrong, just useless

How can something that’s “correct” (tautologically) be useless, or even worse, prevent progress?

Because CICO-bots typically try to reduce every argument to their energy balance gospel.

If we return to our “putting money in the house” analogy real quick: say you built a new garage, fixed the roof, and installed new kitchen appliances. The estimated market price of your house goes up.

But when you talk to your friend, he denies that any of those made a difference - “you were just putting money in the house!”

Yet there are a myriad ways of “putting money in the house” that won’t raise its market value. You could put a pile of cash in the living room and set it on fire. You could pay people to dig ditches and fill them back up in the yard.

The vast majority of the (infinite) ways of “putting money into the house” or “reducing calories” don’t actually work for the intended goal, raising the market price of the house, or achieving sustainable fat loss.

That’s why CICO being a useless tautology isn’t harmless, it’s actually hindering progress. We could be figuring out how people achieve a meaningful deficit. But every time we do, we get shouted at by the CICO cultists and their energy balance gospel.