Discover exactly how many calories you need to lose weight safely and sustainably. No guesswork, just science.
A calorie deficit occurs when you consume fewer calories than your body burns in a day. Your body needs energy (calories) to maintain basic functions like breathing, circulation, and digestion — this is called your Total Daily Energy Expenditure (TDEE). When your intake falls below your TDEE, your body turns to stored fat for fuel, leading to weight loss over time.
Calorie Deficit = TDEE − Daily Calorie Intake
Example: If your TDEE is 2,400 kcal and you eat 1,900 kcal, you have a 500-calorie deficit. Over a week, that's a 3,500-calorie deficit — roughly equivalent to 0.5 kg (1 lb) of body fat.
A moderate deficit (300–500 kcal/day) helps preserve lean muscle mass while burning stored fat, unlike crash diets.
Slow, steady deficits prevent the rebound effect and metabolic slowdown that cause yo-yo dieting.
Your TDEE depends on your age, weight, height, and activity level. One-size-fits-all diets don't account for your unique metabolism.
With a calorie target, you can monitor progress and make data-driven adjustments when weight loss stalls.
| Deficit | Result |
|---|---|
250 kcal/day Gentle | ~0.25 kg/week. Ideal for maintaining muscle and energy during mild dieting. |
500 kcal/day Recommended | ~0.5 kg/week. The gold standard for sustainable fat loss with minimal muscle loss. |
750 kcal/day Moderate | ~0.75 kg/week. Effective but may require careful protein intake to preserve muscle. |
1000 kcal/day Aggressive | ~1 kg/week. Higher risk of muscle loss, fatigue, and nutritional deficiencies. |
Source: Calculations based on the Mifflin-St Jeor equation, the gold standard for TDEE estimation in clinical research.
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