Why “calories in, calories out” is flawed

The Japanese alternative for healthy but joyful eating

Illustrations by Kaki Okumura

I believe that calories are a helpful tool when it comes to understanding how much you’re eating, but it doesn’t tell the whole story.

There are many interesting things that we can explore when we talk about the idea of “calories in, calories out” — like gut microbiome, metabolism, how our bodies adapt to weight and composition changes — but I’m actually going to set those topics aside for now.

Because even without these considerations, there is something fundamentally flawed about using calorie tracking as the foundation of our health goals.

“What’s wrong with counting calories?”

If you consume less calories than your body uses, you will lose weight — that’s true! But let’s examine how we determine these numbers.

In scientific terms, a calorie is a unit of energy — 1 Calorie (or kilocalorie, kcal) is the amount of energy needed to raise the temperature of 1kg of water by 1 degree Celsius.

Back in the old days to measure food calories, food would be placed in a sealed container and submerged in water. The food would then be heated up until it effectively disintegrated, and then the rise in water temperature…