How Many Calories Should I Eat to Lose 1kg Per Week?

Published August 2, 2026 · 5 min read

One kilogram per week is a specific, measurable goal. Whether you can hit it comfortably depends on your current calorie maintenance level, which is different for every person. The maths behind it is consistent though, and understanding it tells you exactly what kind of deficit you need to create to reach that rate of loss.

The Energy Math Behind 1kg of Fat

One kilogram of fat stores approximately 7,700 calories. To lose 1kg per week you need to burn 7,700 more calories than you consume over seven days. That works out to a daily deficit of about 1,100 calories.

For some people that is a very reachable deficit. For others it puts their intake dangerously low. The key variable is your total daily energy expenditure, usually called TDEE, which is the total number of calories you burn each day through your metabolism, movement, and exercise combined.

Finding Your Personal Starting Point

If your TDEE is 3,000 calories per day, an 1,100 calorie deficit leaves you eating 1,900 calories. That is a substantial cut but achievable for a larger person or someone quite active. You would lose roughly 1kg per week without going below safe intake levels.

If your TDEE is 1,800 calories per day, an 1,100 calorie deficit would leave you eating only 700 calories. That is insufficient for any adult and would cause muscle loss, nutritional deficiencies, and metabolic adaptation. In that case going for 0.5kg per week (a 550 calorie deficit) is far more appropriate and sustainable.

1kg Per Week Is Not Always the Right Goal

Many nutrition guidelines consider 0.5 to 1kg per week to be the recommended rate for sustainable fat loss. The upper end requires a sizeable deficit that many people struggle to maintain. Research consistently shows that slower weight loss is associated with better preservation of muscle mass and a higher likelihood of keeping the weight off long term.

Losing muscle while dieting is a real risk. When you eat too little, your body breaks down muscle tissue for energy alongside fat. Muscle is metabolically expensive to maintain, so a very aggressive deficit can cause your body to shed it. Lower muscle mass means a lower resting metabolism, which makes future weight management harder.

How to Hit a 1,100 Calorie Daily Deficit Practically

The most sustainable approach combines a calorie reduction from food with an increase in calories burned through exercise rather than trying to cut food alone.

For someone with a 2,800 calorie TDEE aiming for 1kg per week, one approach might be eating 2,100 calories rather than 2,800 (a 700 calorie food-based deficit) while burning an additional 400 calories through exercise three to four times per week. The averaged daily deficit comes to right around the 1,100 calorie target. This is much easier to maintain than cutting 1,100 calories from food alone.

Why the Number on the Scale Changes

Body weight fluctuates daily based on water retention, sodium intake, digestion, hormones, and muscle glycogen. You might cut 1,100 calories consistently and see your weight jump by 1kg one day and drop by 1.5kg the next. Weekly averages over three to four weeks are far more useful than daily readings for assessing whether your deficit is working.

Weigh yourself at the same time each day, ideally in the morning after using the bathroom and before eating. Record the number but assess the trend across seven-day averages rather than reacting to any single measurement.