Weight Management

Calorie Deficit: How It Actually Works

6 min readKilotaki Nutrition Editor
Calorie Deficit: How It Actually Works

Calorie deficit = consuming fewer calories than you burn. 0.5 kg fat ≈ 3500 kcal. Daily deficit of 500 kcal = ~0.5 kg/week loss. Aggressive deficits (>1000 kcal) cause muscle loss + metabolic adaptation. Sustainable: 300-500 kcal/day deficit.

Why Aggressive Cuts Fail

Body senses 'famine' — drops BMR 5-15%, reduces NEAT (fidgeting/non-exercise activity), increases hunger hormones. Result: plateau + rebound when normal eating returns.

Sustainable Approach

TDEE × 0.85 for weight loss. Track honestly 1-2 weeks first. Adjust based on real progress (not theoretical numbers). Diet breaks (1-2 weeks at maintenance every 8-12 weeks) help.

Frequently Asked Questions

Should I cut weekends and bulk weekdays?

No. Total weekly intake matters. Crash dieting + binge cycle is most stressful and ineffective.

Scientific References

  1. Hall KD (2012) Quantification of the effect of energy imbalance. Lancet.

This content is for general information only and does not replace medical advice. Consult your physician or a registered dietitian for personalized guidance.

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