What Is a Calorie Deficit?
A calorie deficit occurs when a person consumes fewer calories than their body uses, so the body draws on stored energy. It is the basic energy-balance principle behind weight loss. The size of a deficit is the difference between total daily energy expenditure and calories eaten.
Rules of Thumb and Their Limits
The traditional estimate that about 3,500 calories equal one pound (about 0.45 kg) of body fat is a simplification; real results vary because the body adapts over time.
Professional Guidance
Health authorities advise that significant dietary changes be discussed with a doctor or registered dietitian.
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🔗 Related Terms
More Health & Fitness Terms
- Body Composition
- Body Fat Percentage
- Body Mass Index (BMI)
- Calorie
- Circadian Rhythm
- Estimated Due Date (EDD)
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Last updated: September 27, 2026. This definition is for general educational purposes only. It is not financial, investment, tax, legal, or medical advice, and it does not recommend any product or course of action. For decisions about your own situation, consult a qualified professional.