Calories in versus calories out. What you eat minus what you burn. Eat less, move more. There are a million other ways to shorthand the myth that weight loss is nothing more than a simple math equation. And it is a myth, one that I’d like to help you debunk. Let’s take a closer look.

The myth:

If I burn more calories than I eat, I will lose weight.

1 pound is equal to 3500 calories, so I need a deficit of 3500 calories to lose a pound.

If I am 5’6” and 150 pounds, and am moderately active, according to the “formulas” I need to eat 2,500 calories to maintain my weight.

If I eat 2000 calories a day and burn 200 calories a day exercising, this creates a deficit of 700 calories a day so after 5 days I should lose a pound.

Let’s break this down.
Let’s just say that you’re off by a tiny bit. You unknowingly consume 100 calories a day more than your maintenance caloric need. Do you know how easy it is to miscalculate 100 calories in one day? Our food labels aren’t even precise enough to guarantee this wouldn’t happen even if you measure everything you eat. But I digress. Ok, you’re off by 100 calories. You would then gain 10 pounds a year, or 50 pounds in five years, or 100 pounds 10 years. And the opposite is true. If you consume 100 calories less than your maintenance need, you would lose 100 pounds over 10 years. And that’s by miscalculating a teaspoon of peanut butter.

To believe our bodies don’t compensate for even a small fluctuation in calories defies common sense. It also defies science. Our bodies are not calculators. They were designed to keep us alive and our metabolism fluctuates depending on a multitude of factors including stress, muscle mass, lack of sleep, illness, menstrual cycles, and so many more!

It’s also almost impossible to calculate exactly how many calories you burn during exercise because again, so many factors contribute. And no, your Fitbit cannot do this accurately for you. The fact that most people maintain a weight fluctuating within a few pounds from day to day is indicative of how well our bodies respond to environmental and internal changes.

Another reason counting calories doesn’t work is that multiple studies show us that if you lose weight, especially a significant amount, your body responds by slowing down its metabolism. This is one theory of why it’s so difficult to maintain weight loss. Your body interprets this as starvation, and in an intelligent attempt to keep you alive, your metabolism slows leading to decreased energy and increased hunger. So now you’re burning calories less efficiently, eating more due to hunger, and completely unmotivated to exercise due to fatigue. A triple whammy sure to pack the pounds back on.

We know that the quality of calories matters much more than the quantity of calories. Calories in versus calories out tell me 100 calories from a cookie is the same as 100 calories from an apple or a piece of fish. Wrong. Here’s why.

Insulin is the hormone most famously known for allowing cells to use glucose, or sugar, for energy. The other major role of insulin, however, is to shunt excess energy from fats, carbohydrates, and proteins into fat cells for storage. More insulin means more storage, which means bigger fat cells and heavier weight. Chronic high levels of insulin reak havoc on our bodies and lead to diabetes and heart disease- a much more concerning problem than weight itself. When you eat the cookie, blood sugar levels rise very quickly, which causes a surge of insulin. Because we typically don’t need that much energy right away (unless you’re running a marathon), the high insulin levels then promote storage of excess energy into fat cells.

An apple, on the other hand, is high in fiber which allows for much slower digestion and absorption, and subsequently lower levels of insulin. The fish, which is mostly protein, is also digested much more slowly and requires less insulin. And with less insulin comes less storage in the fat cells. There is also less hunger, which is why you feel more full after eating a chicken breast than a bag of chips.

I’ve mentioned only a few of the processes and hormones involved in digestion and metabolism. There are many more. Your body is a complex engine with many moving parts, and the type of calories you eat matter. For years we’ve touted eat less, move more. Eat a cookie then run a mile. Instead, we should be saying “eat better.” Eat foods our bodies process efficiently and don’t promote storage, fatigue, and hunger. This means cutting way back on processed foods, too much sugar, and not enough whole foods and fruits and vegetables. If weight loss is in the cards, it has to start with eating better calories.

Yes, an overall calorie deficit is needed for weight loss, but this needs to occur on a macro level, not a micro one. Our bodies compensate for minor fluctuations in calories consumption and energy expenditure. Instead, focus on eating enough food that your body doesn’t feel deprived. Make most of the food you chose quality calories such as those from fruits, vegetables, and lean meats. Don’t sweat it if you want dessert, it’s not enough of an impact to throw you off. And stop counting calories.