LeanCalc

What is a calorie deficit?

A calorie deficit happens when you consume fewer calories than your body burns in a day. Your body's total daily energy expenditure (TDEE) includes everything it burns: breathing, digestion, movement, and exercise. When your intake falls below this number, your body turns to stored fat for fuel, resulting in weight loss.

How many calories should I eat to lose weight?

There is no universal answer; it depends on your height, weight, age, sex, and activity level. That is why calculators like this one use the Mifflin St Jeor equation, widely considered the most accurate formula for estimating your resting metabolic rate (BMR). Your BMR is then multiplied by an activity factor to give your TDEE, and your target is TDEE minus your chosen deficit.

What is a safe calorie deficit?

Most nutrition experts consider a deficit of 250 to 750 calories per day safe for healthy adults. Going below 1,200 kcal per day (women) or 1,500 kcal per day (men) is not recommended without medical supervision; it risks muscle loss, fatigue, and nutritional deficiencies. If you are new to dieting, start small (250 to 300 kcal per day) and increase gradually as your body adjusts.

What macros should I eat on a calorie deficit?

Protein is the most important macro when cutting. A higher intake (about 40% of calories) preserves muscle mass during a deficit. LeanCalc uses 40% protein, 35% carbs, 25% fats, a well-researched split for fat loss while maintaining strength and energy.