Calories-In, Calories-Out: Common Sense or Nonsense?

Calories in, calories out is the most prevalent and “common sense” diet advice in our culture. Even books that have nothing to do with nutrition refer to it to make various points as if it’s an unarguable universal law. Unfortunately, just because something is common sense, doesn’t mean it’s true, wise, or helpful.

The theory goes that fat gain and fat loss is simply based in the laws of thermodynamics. If you eat more calories than you burn, you gain weight. If you eat fewer calories than you burn, you lose weight. While it’s true that the energy we consume has to go somewhere, there’s a number of problems with this overly simplistic paradigm of how the body uses energy.

1. When we simply manipulate the amount of calories we eat or expend without taking hormonal factors into consideration, the weight we lose or gain from this approach can be either fat or lean body mass such as muscle and bone.

2. While we can do pretty well at controlling our calories in (for a short time), we cannot AT ALL control our calories out and our bodies will slow metabolism to maintain equilibrium, making it harder and harder to lose weight and easier and easier to gain it.

3. Inevitably after a period of low calorie dieting, our bodies will ramp up hormones to force us to eat, making us hungrier and more likely to go for high-energy foods. Will power is no match for your body’s survival mechanisms!

4. What our bodies do with the energy (calories) we consume is completely controlled by hormones, which the calories-in, calories-out model ignores.

As Dr. Jason Fung says in his paradigm-shifting book The Obesity Code, “Virtually every person who has used caloric reduction for weight loss has failed.” This is not because we are lazy, lack will power, or embody any other personal or moral failure. We simply cannot control the amount of fat our bodies accumulate by controlling our caloric intake.

So if we can’t control our calories for fat loss, how are people losing weight? Is there anything we can do if this is our goal?

What our bodies do with energy is extremely complicated and the truth is that even the most forward-thinking scientists don’t know exactly what’s going on, although we have a much better idea now than we did years ago. While we can definitely influence fat loss (and fat gain), we don’t have complete control. The amount of fat our bodies accumulate has to do with hormones, the gut microbiome, genetics, energy consumption and expenditure, and many other factors. But here is what we do know:

1. The body cannot tap into fat stores if insulin is too high. This is one of the primary reasons typical low calorie diets don’t work and cause metabolic problems instead. When insulin is too high from years of excess energy consumption or simply from eating all day (even if what you’re eating is low calorie!), your body simply cannot access its stored body fat for fuel and it’ll start going into starvation mode, ramping up hunger hormones and lower metabolic rate.

2. When we keep our insulin low by reducing how often we eat (intermittent fasting) and lowering the amount of refined carbohydrates we eat, our bodies are free to use our stored body fat as fuel, making us less hungry and reducing the amount of body fat we have stored.

3. When we eat whole foods, we usually won’t be able to eat enough energy to gain fat. The biggest contributor to fat gain is processed foods including refined sugars, flours, and oils, but also things like fruit juices.

4. Building and using muscle can be helpful with fat loss, not because of the energy expended, but because muscle cells don’t need insulin to take in energy from the blood. This means we can lower our blood sugar and keep our insulin low by allowing our muscles to become a place where blood glucose can go.

5. Subcutaneous fat can actually be beneficial metabolically, while visceral fat can be dangerous. Subcutaneous fat is the fat just underneath the surface of our skin - the fat you can jiggle and pinch. Visceral fat is the fat around our organs, which you can’t see or feel. If we are gaining fat, the greater ability we have to store it subcutaneously, the better.

While counting calories might be tempting or seem easy since we can do it with an app, it’s dangerous territory to get into. We don’t know how many calories our bodies need, and trying to starve our bodies into weight loss through will power and caloric control can be counter-productive, causing problems down the road.

It’s important to listen to our bodies and give them the nourishment they need, while not overloading them with energy they don’t know what to do with. This can take some practice and experimentation, working with the body’s hormonal environment to create healthy conditions for weight loss, if that is the goal.

If you’d like support unlearning diet rules and learning to work with your body rather than against it, schedule a free consultation with me.