What a deficit actually is
Your body uses energy to stay alive and move around. If you take in less energy than it uses, it makes up the difference from stored energy — mostly body fat. That gap between intake and use is the deficit.
There is nothing magical about specific diets. Low-carb, high-protein, plant-based and standard balanced diets all work for fat loss when they create a deficit.
How big should the deficit be?
For most people, 300–500 kcal/day below maintenance is the sweet spot. That produces around 0.25–0.5 kg of loss per week without leaving you exhausted or hungry all the time.
- Smaller bodies should usually stay closer to 300 kcal/day
- Larger bodies can sustain 500–700 kcal/day comfortably
- Bigger deficits are not always faster in practice — they are harder to stick with
Use a calculator to set your number
The calorie deficit calculator turns your stats and goal into a daily target in seconds. It is an estimate, not a contract — adjust based on real-world results over 2–3 weeks.
Protect your protein
When you eat less, your body looks for energy anywhere it can find it — including muscle. Higher protein (around 1.6–2.0 g/kg of body weight) preserves muscle and keeps you fuller for longer.
Diet breaks are allowed
Long unbroken stretches of dieting are mentally and physically tiring. A week at maintenance every 6–8 weeks gives you a real break without losing momentum.
When weight loss stalls
Weight rarely drops in a straight line. If the scale has not moved for 2–3 weeks, check your logging honestly, recalculate your TDEE and adjust by 100–200 kcal/day if needed.
GudFude provides estimates for general guidance only. It is not medical advice. If you have a medical condition, are pregnant, or have a history of disordered eating, please speak to a qualified clinician before changing how you eat.