Nutrition

Calories In vs. Calories Out: The Core of Weight Loss

When it comes to losing weight, the principle of "calories in vs. calories out" (CICO) forms the foundation of nearly every successful approach. This concept revolves around the energy balance equation: the number of calories you consume versus the number of calories your body burns. If you take in more calories than you burn, you gain weight. If you burn more than you consume, you lose weight.

Calories in refers to everything you eat and drink. Every bite—from a salad to a slice of cake—adds to your total energy intake. These calories come from macronutrients: carbohydrates, protein, and fat. Tracking what you eat can help you stay aware of how much energy you’re consuming daily.

Calories out involves the energy your body uses for basic functions (like breathing and digestion), physical activity, and non-exercise movements (like fidgeting or walking to the fridge). Increasing your physical activity—through exercise or just being more active—raises your calorie expenditure and helps create a calorie deficit.

To lose one pound of fat, you need to burn roughly 3,500 more calories than you consume. This can be achieved through a combination of eating less and moving more. For example, reducing your intake by 500 calories a day can lead to about one pound of fat loss per week.

While the CICO model is scientifically sound, it doesn’t mean all calories are equal in terms of nutrition. Choosing whole, nutrient-dense foods over processed options supports overall health and can help you feel full while eating fewer calories.

In the end, consistent calorie control—eating slightly less than you burn—is the key to weight loss. No matter what diet you follow, success boils down to maintaining a calorie deficit over time.

Want help tracking or getting those extra   calories burned each day?  We offer  virtual fitness training and nutrition coaching. Give us a  call today!