Calorie Deficit Guide
How to lose fat while preserving muscle mass during a cut.
What is a calorie deficit?
A calorie deficit means eating fewer calories than your body burns daily. A 500 calorie deficit leads to approximately 0.5kg (1lb) of fat loss per week. This is the only scientifically proven way to lose body fat.
TL;DR
- •A 300-500 kcal/day déficit is optimal for fat loss while preserving muscle mass
- •High protein intake (1.8-2.2g/kg) is essential during a déficit to protect muscle tissue
- •Never cut below your BMR — overly aggressive déficits cause muscle loss and metabolic adaptation
- •Ideal cut duration is 8-12 weeks, followed by a maintenance phase
- •Resistance training during a déficit matters more than cardio for body recomposition
Quick answer: A 500 calorie deficit per day is optimal for losing ~0.5kg/week of fat while preserving muscle. Keep protein high (2.0-2.2g/kg) and don't reduce training intensity.
Calculate Your Deficit
Find out how many calories to eat to lose fat at the optimal rate.
Calculate FreeWhat is a Calorie Deficit?
A calorie deficit means eating fewer calories than you burn (TDEE). This forces your body to use energy reserves (fat) to make up the difference.
Formula:
Deficit = TDEE - Calories Eaten
If TDEE = 2500 and you eat 2000, deficit = 500 kcal/day
How Much Deficit is Optimal?
| Deficit | Loss/Week | Muscle Risk | Sustainability |
|---|---|---|---|
| 250-300 kcal | 0.25-0.3kg | Minimal | High |
| 500 kcal | 0.5kg | Low | Good |
| 750 kcal | 0.7-0.8kg | Moderate | Medium |
| 1000+ kcal | 1+kg | High | Low |
How to Preserve Muscle in a Deficit
Do This
- • High protein: 2.0-2.2g/kg
- • Maintain intensity (same weights)
- • Reduce volume if needed, not intensity
- • Sleep 7-9 hours
- • Moderate deficit (max 500 kcal)
Avoid This
- • Too aggressive deficit (>750 kcal)
- • Reducing weights in the gym
- • Too much high-intensity cardio
- • Low protein (<1.6g/kg)
- • Deficit for >16 weeks straight
Cutting Duration
Recommendation: 8-16 weeks of cutting
After 16 weeks, metabolism adapts and loss slows. Do 4-8 weeks at maintenance before resuming.
Cardio in a Deficit: Yes or No?
Cardio is optional. The deficit comes from diet, not exercise. If you do cardio:
- Prefer LISS (walking, easy cycling) - doesn't interfere with recovery
- 10,000 steps/day is enough for most people
- Don't use intense HIIT - it competes with weight training
Arvo Optimizes Your Cutting Training
In a deficit, Arvo automatically reduces volume while maintaining intensity to preserve muscle mass while you lose fat.
Try it freeFrequently Asked Questions
What is a good calorie deficit for fat loss?
A deficit of 300-500 calories per day is optimal for fat loss while preserving muscle. This results in 0.3-0.5kg (0.7-1lb) of fat loss per week. Larger deficits (750-1000 kcal) speed up fat loss but increase muscle loss risk and are harder to sustain.
How long should I stay in a calorie deficit?
Most cutting phases last 8-16 weeks. Longer than 16 weeks increases metabolic adaptation and muscle loss risk. After a cut, transition to maintenance calories for 4-8 weeks before cutting again or starting a bulk.
Will I lose muscle in a calorie deficit?
Some muscle loss is possible, but you can minimize it by: keeping protein high (2.0-2.2g/kg), maintaining training intensity (don't drop weights), keeping deficit moderate (500 kcal max), and getting adequate sleep. Most people can cut with minimal muscle loss following these guidelines.
Should I do cardio or just diet for fat loss?
Diet creates the calorie deficit; cardio is optional but can help. A 500 calorie deficit from diet alone works perfectly. If adding cardio, use low-intensity cardio (walking) to avoid interfering with recovery. Don't rely on cardio to 'burn off' overeating.