Calorie deficit = consuming fewer calories than you burn. To lose 1 kg (2.2 lbs) = 7,700 calorie deficit. Daily deficit of 500 cal = 0.5 kg loss/week. Weekly deficit of 3,500 cal = 0.5 kg loss.

Safe: 0.5-1 kg (1-2 lbs) per week. Faster weight loss may: harm metabolism, cause muscle loss, trigger nutritional deficiencies, increase gallstone risk. Very rapid loss (>1.5 kg/week) requires medical supervision.

TDEE (Total Daily Energy Expenditure) = total calories you burn daily. Includes: basal metabolic rate (BMR) + activity level. Use TDEE calculator on site. Or estimate: BMR × activity multiplier (1.2-1.9).

Depends on goal. Example: 20 kg to lose at 0.5 kg/week = 40 weeks (9 months). Shorter timelines (aggressive) risk muscle loss and metabolic damage. Gradual loss (conservative) preserves muscle.

Yes. Rapid weight loss (<0.5 kg/week) may be water/muscle, not fat. Very rapid (>1.5 kg/week) causes: muscle loss, metabolic slowdown, gallstones, nutrient deficiencies, yo-yo rebound.

Yes. Exercise increases daily calorie burn (TDEE), allowing larger deficit without extreme diet restriction. Resistance training preserves muscle during weight loss. Cardio alone may lose weight + muscle.

Plateaus common after 4-8 weeks. Causes: metabolic adaptation, water retention, muscle gain offsetting fat loss. Solutions: adjust deficit, increase activity, cycle calorie intake, reduce stress.

Calculator provides estimates using standard formulas (7,700 cal = 1 kg). Actual weight loss varies based on: metabolism, hormones, water retention, muscle gain, food quality. Not medical advice—consult doctor.