A caloric deficit occurs when you eat fewer calories than your Total Daily Energy Expenditure (TDEE). This forces your body to use stored energy (fat) for fuel, resulting in weight loss.
How Much Deficit?
- Small deficit (250–500 cal/day): 0.5–1 lb/week loss. Sustainable, preserves muscle.
- Moderate deficit (500–750 cal/day): 1–1.5 lb/week. Effective but requires tracking.
- Aggressive deficit (1000+ cal/day): 2+ lb/week. Risk of muscle loss and metabolic slowdown.
Key Principle
One pound of body fat ≈ 3,500 calories. A 500 cal/day deficit ≈ 1 lb/week loss. Combine with adequate protein (0.8–1g/lb bodyweight) and strength training to preserve muscle during a deficit.