How Many Calories Should You Eat to Lose 1kg Per Week?
The Short Answer
To lose 1kg per week, you need a daily calorie deficit of approximately 1,100 calories below your Total Daily Energy Expenditure (TDEE). That's because 1kg of body fat contains roughly 7,700 calories (7,700 ÷ 7 days = 1,100/day).
However, most nutrition experts recommend a more moderate deficit of 500–750 calories per day, which leads to a safer rate of 0.5–0.75kg per week.
Why 1kg Per Week Might Be Too Aggressive
While losing 1kg per week is technically possible, a 1,100-calorie daily deficit can be unsustainable for many people. Here's why:
- Muscle loss: Aggressive deficits cause your body to break down muscle for energy, not just fat.
- Metabolic adaptation: Your body lowers its metabolic rate to conserve energy, making further weight loss harder.
- Nutrient deficiencies: Eating too little makes it difficult to get all essential vitamins and minerals.
- Hunger and fatigue: Large deficits cause intense hunger, brain fog, and poor exercise performance.
How to Calculate Your Calorie Target
Step 1: Find Your TDEE
Your TDEE (Total Daily Energy Expenditure) is the total number of calories you burn each day, including:
- BMR (Basal Metabolic Rate) — calories burned at rest
- Activity — exercise and daily movement
- TEF (Thermic Effect of Food) — energy used to digest food
Use a free TDEE calculator to find your number. For example, a 30-year-old woman who is 165cm, 75kg, and moderately active has a TDEE of approximately 2,200 calories.
Step 2: Subtract Your Deficit
For safe, sustainable weight loss:
| Goal | Daily deficit | Weekly loss |
|---|---|---|
| Gentle | 300 kcal | ~0.3kg |
| Moderate | 500 kcal | ~0.5kg |
| Aggressive | 750 kcal | ~0.7kg |
| Maximum | 1,100 kcal | ~1.0kg |
- Moderate deficit: 2,200 - 500 = 1,700 calories/day
- Aggressive deficit: 2,200 - 750 = 1,450 calories/day
Step 3: Never Go Below Minimum Thresholds
Regardless of your deficit calculation, never eat below:
- 1,200 calories/day for women
- 1,500 calories/day for men
Going below these levels without medical supervision risks serious health consequences.
Tips for Maintaining a Calorie Deficit
- Prioritise protein — Aim for 1.6–2.2g per kg of body weight. Protein preserves muscle mass and keeps you fuller for longer.
- Eat high-volume, low-calorie foods — Vegetables, fruits, and soups fill your stomach without excessive calories.
- Track your intake — Use a food diary to stay accountable. People consistently underestimate how much they eat.
- Move more — Adding 30 minutes of walking burns ~150 extra calories, reducing how much you need to cut from food.
- Recalculate every 5kg — As you lose weight, your TDEE drops. Recalculate to avoid plateaus.
The Bottom Line
Losing 1kg per week requires a 1,100-calorie daily deficit, which is aggressive for most people. A moderate deficit of 500 calories per day (0.5kg/week) is more sustainable, protects muscle mass, and is far easier to maintain long-term.
Use CalCalc's free calculator to find your personalised calorie target, and track your progress with the food diary.