If you’ve ever tried losing weight, you have probably heard of the importance of “calories in vs. calories out.” The calories in vs. calories out model is based on  on the idea that to maintain a stable weight, the number of calories you eat, needs to match the number that you expend. “Calories in” refers to the calories you get from the foods you eat while “calories out” is the number of calories that you burn. 

Our bodies burn calories three different ways: 

1.Basic Metabolism: Your body uses most of the calories you get from food to sustain basic functions such as your heartbeat. This is called your basal metabolic rate.

2.Digestion: Around 10-15% of the calories that you eat are used to power digestion. This is known as the thermic effect of food, and varies based upon what kind of foods you’re eating. 

3. Physical Activity: The leftover calories that you get from your diet are meant to fuel your physical activity. This isn’t just your workouts, but also your daily tasks like washing the dishes or even reading a book. 

When the number of calories you take in from food matches the number of calories you burn to sustain your metabolism, digestion and physical activity your weight will remain stable. Therefore, calories vs. versus calories out model is very much so true. You NEED a calorie deficit in order to lose weight. 

Weight Loss Requires a Calorie Deficit

There is absolutely no way around this principle. Biologically, you have to eat fewer calories than you’re burning. Once your body’s energy needs are met, extra calories are stored for future use. Thats why when you eat more calories than you burn, you gain weight whereas eating fewer calories than you need will cause weight loss. 

Health is more than just “calories in vs. calories out”

While the”calories in vs. calories out” model matters for weight loss, not all calories are equal when it comes to your health. Thats because different foods have different effects on various processes in your body, regardless of calories contents. The source of calories impacts your hormones and health, how full you feel, and your metabolism differently regardless of the number of calories that they contain.

Nutrient Density matters:

The amount of nutrients a food contains per calorie can vary immensely. Nutrient-dense foods provide higher amount of vitamins, minerals, and beneficial compounds per gram than less nutrient dense foods. Examples for nutrient dense foods would be fruits, vegetables, whole grains, legumes, meat, fish, poultry, dairy, nuts and seeds. 

The bottom line: 

Biologically, you must be in calorie deficit to lose weight therefore “calories in vs. calories out” matters. It is actually the number one principal you must look at when it comes to weight loss. You will not lose weight, no matter what foods you’re eating if you’re not in a calorie deficit. Keep in mind though, that the foods you put in your body play a big role in how you feel. So stay in your deficit filling your body with rich, nutrient dense foods.