Why a Calorie Deficit is the Only Way to Lose Weight

Keto, Paleo, Intermittent Fasting—there are a million ways to eat, but there is only one way to lose weight: a calorie deficit. It's not magic; it's thermodynamics.

The Energy Balance Equation

Your body needs a certain amount of energy (calories) just to exist. This is your Basal Metabolic Rate (BMR). You burn additional calories through movement and exercise.

• Calories In: Food and drink.
• Calories Out: BMR + Physical Activity + Digestion.

If Calories In < Calories Out, you lose weight. Your body taps into its fat stores for the missing energy.

How Large Should Your Deficit Be?

A safe rate of weight loss is 0.5 to 1 kg (1-2 lbs) per week. To lose 0.5 kg of fat, you need a deficit of roughly 3,500 calories, or 500 calories per day.

Use our BMI Calculator to assess your starting point, and consider using a TDEE (Total Daily Energy Expenditure) calculator to find your maintenance calories.

Quality Still Matters

While you could lose weight eating only junk food if you stayed in a deficit, you would feel terrible. Nutrient-dense foods (vegetables, lean proteins, whole grains) keep you full longer and provide the energy you need to stay active.

Focus on sustainable changes, not crash diets. The goal is to lose weight and keep it off.