Calories In/Calories Out Debate

Calories in, calories out is a valid model. It's just not a very useful one. The reason that some foods are better than others even though they have the same number of calories is that some foods give you the feeling of being full, which causes you to eat fewer calories later (e.g. protein). Or some foods might cause you to feel fatigued, causing you to burn fewer calories later (sugar crash). But don't kid yourself, if it's a given that you eat X calories and burn/lose Y calories, then you'll g

It's the calorie deficit that matters.

Not OP, but the general logic behind "calories in = calories out" is obviously fine. However, just knowing this doesn't really tell you anything about the best way to go about decreasing "calories in" or increasing "calories out" in a way that will result in meaningful fat loss and improved health. For example, it is plausible that someone could reduce "calories in" by eating less and their body could make up the difference by reducing "calories

"Calories in / calories out" is far from scientific. 500 calories of ice cream will not have the same effect on your body as 500 calories of lean chicken breast. It's a very rough approximation intended to get people thinking about their calorie intake and expenditures, but it's becoming very annoying to see people representing it as some kind of quantifiable scientific formula.

The idea that the only way to lose weight is to reduce calorie intake to below calorie burn is not true in any practical sense.And it's not just a matter of willpower.If you add up the calories in the food you eat, then subtract the calories you burn through exercise, respiration, beating heart, etc., you cannot compute weight gain or loss.That's because the body doesn't use 100% of calories in food. Some calories are never absorbed and are excreted as waste. And if you e

The calories in/calories out model does work as long as you properly count the calories going in. The number shouldn't be what's on the nutrition label since that assumes an ideal digestive system that can fully extract all the energy from the food that a person eats.This number doesn't include factors such as the health of the person. If the person has digestive problems such an a malfunctioning intestine and can't digest and absorb the energy from the food, then amount of calories extracted

"Calories In vs Calories Out is correct". Maybe it’s correct but I doubt it’s useful. How do you explain that people who do not count calories maintain their weight ?

The issue with the simplifying "calories in == calories out" is that conservation of energy is being applied over the wrong system. Our bodies are not 100% efficient at extracting energy from food, and to GP's point respond differently to different types of foods.

At the pure physical level, yes: calories remaining = calories in - calories outHowever, the "calories out" portion of that equation is actually quite complicated. In recent years many studies have indicated that the body does not process all calories in the same way. So "calories out" depends on a lot of things, including:- metabolism, which can be increased by exercise and muscle mass- what specific kind of "calories in" you're getting, and how your

Unfortunately calories out is a function of calories in.You eat less calories, your body might start consuming less calories.Also, there are two different pathways for using glucose in the body: aerobic and anaerobic. The aerobic one produces 15x more ATP (cellular level energy) than the anaerobic one. The anaerobic one wastes more as heat. So if for some reason you're in the second one, even though you ingest the same amount of calories, the amount of energy you have usable is much l