You want to lose weight and you have heard that you need a calorie deficit. But how many calories per day should you actually eat? Too few and you feel miserable, lose muscle mass, and slow your metabolism. Too many and nothing changes. The good news: with a few calculations, you can find exactly where you need to be.
Key takeaways
- A calorie deficit is necessary for weight loss. You need to eat fewer calories than you burn. A deficit of 500 kcal per day leads to roughly 0.5 kg of weight loss per week.
- Never go too low. Health authorities recommend a minimum of 1,500 kcal per day for women and 1,800 kcal for men on an energy-restricted diet.
- Protein is crucial. Eat 1.6 to 2.0 grams of protein per kilogram of body weight to preserve muscle mass while losing weight.
- A mild deficit works better long term. A deficit of 300 to 500 kcal is sustainable. Larger deficits lead to relapse more often.
- Metabolic adaptation is real. Your body adjusts to lower calorie intake, so actual weight loss is often less than calculations predict.
What is a calorie deficit and how does it work?
A calorie deficit occurs when you eat fewer calories than your body burns. Your body compensates for that difference by using stored energy -- mostly body fat, but also partly muscle tissue if you are not careful.
Your Total Daily Energy Expenditure (TDEE) consists of three components:
- Basal Metabolic Rate (BMR). The energy your body uses at rest: breathing, heartbeat, cell renewal. This accounts for 60 to 75 percent of your total burn.
- Thermic Effect of Food (TEF). The energy needed to digest food. Roughly 10 percent of your total.
- Physical activity. From climbing stairs to exercise. This is 15 to 30 percent of your total and the component you have the most control over.
Want to calculate your TDEE? Use the Mifflin-St Jeor equation from our article on calculating your daily calorie needs. Your TDEE minus your chosen deficit equals the number of calories you can eat per day to lose weight.
How many calories per day to lose weight?
It depends on how quickly you want to lose weight and what is sustainable for you. Below are the three common deficit levels with expected results.
| Deficit type | Daily deficit | Expected loss per week | Suitable for |
|---|---|---|---|
| Mild | -300 kcal | ~0.3 kg | Those who want slow, sustainable weight loss |
| Standard | -500 kcal | ~0.5 kg | Most people (recommended by health authorities) |
| Aggressive | -750 kcal | ~0.6 to 0.7 kg | Short periods under professional guidance |
Important. These expected loss figures are theoretical. In practice, your body adapts to lower calorie intake (metabolic adaptation). Actual weight loss is therefore often slightly less, especially after the first few weeks. This is normal and not a reason to increase your deficit.
According to the Dutch Nutrition Centre (Voedingscentrum), the recommendation is to lose no more than 0.5 kg per week. That corresponds to a standard deficit of roughly 500 kcal per day.
Calculation example
A 35-year-old woman, 75 kg, 168 cm, moderately active (PAL 1.6):
- BMR = (10 x 75) + (6.25 x 168) - (5 x 35) - 161 = 750 + 1,050 - 175 - 161 = 1,464 kcal
- TDEE = 1,464 x 1.6 = 2,342 kcal per day
- With standard deficit (-500 kcal): 2,342 - 500 = 1,842 kcal per day
Want to learn more about calculating your specific deficit? Read the detailed article on calculating a calorie deficit.
Why is there a minimum calorie intake?
The Dutch Nutrition Centre (Voedingscentrum) recommends that women do not go below 1,500 kcal per day and men do not go below 1,800 kcal on an energy-restricted diet. Going lower requires medical supervision.
The reasons are:
- Nutrient deficiencies. Below 1,500 kcal, it is virtually impossible to get all essential vitamins, minerals, and nutrients from regular food.
- Muscle loss. Too large a deficit forces your body to break down muscle tissue alongside fat for energy. Less muscle mass means a lower metabolic rate, which makes you gain weight more easily in the long run.
- Metabolic adaptation. Your body responds to a drastic deficit by slowing your metabolism. It enters a kind of "conservation mode" -- you burn less energy at rest, which makes the deficit smaller than you think.
- Mental health. Extremely low calorie intake increases the risk of binge eating, a disrupted relationship with food, and in severe cases, eating disorders.
How many calories women need per day depends on age and activity level. Use that value as the starting point for your deficit -- not the minimum threshold.
Why is protein so important for weight loss?
During a calorie deficit, you lose not only fat but also muscle mass. Adequate protein slows that muscle loss. According to the International Society of Sports Nutrition (ISSN) position stand, the recommendation is 1.6 to 2.4 grams of protein per kilogram of body weight per day for people who are losing weight. For most people, 1.6 to 2.0 grams per kilogram is a good target.
Why does protein help with weight loss?
- Muscle preservation. Protein provides the building blocks (amino acids) your muscles need. More muscle mass = a higher resting metabolic rate.
- Satiety. Protein is more satiating than carbohydrates or fats. You feel less hungry between meals.
- Thermic effect. Your body uses more energy to digest protein (20 to 30 percent) than carbohydrates (5 to 10 percent) or fat (0 to 3 percent).
Protein needs during a calorie deficit
| Body weight | Protein per day (1.6g/kg) | Protein per day (2.0g/kg) |
|---|---|---|
| 60 kg | 96 g | 120 g |
| 70 kg | 112 g | 140 g |
| 80 kg | 128 g | 160 g |
| 90 kg | 144 g | 180 g |
Spread your protein intake throughout the day: 20 to 40 grams per meal is optimal for muscle protein synthesis. Good sources include chicken, fish, Greek yogurt, legumes, eggs, and tofu.
What mistakes should you avoid with a calorie deficit?
1. Too large a deficit
More than 750 kcal deficit per day is unsustainable for most people. It leads to energy loss, concentration problems, and a higher risk of binge eating. Start with a mild to standard deficit and adjust based on results.
2. Only watching the scale
Your weight fluctuates daily by 0.5 to 2 kg due to water retention, digestion, and hormones. Look at the trend over two to four weeks, not daily fluctuations. Weighing once per week at a consistent time gives the most reliable picture.
3. Eating too little protein
Many people in a calorie deficit cut back on protein because protein-rich foods are relatively expensive. That is counterproductive: the resulting muscle loss lowers your metabolism and makes it harder to maintain weight in the long run.
4. Forgetting exercise
You can create a calorie deficit by eating less, moving more, or a combination of both. The combination works best. Walking, cycling, or swimming increase your energy expenditure without feeling like an intense workout.
5. No insight into your actual intake
Most people underestimate their calorie intake by 20 to 50 percent. That means you might think you have a 500 kcal deficit when it is actually 200 kcal. Tracking your food -- even for just a few weeks -- gives you a realistic picture. More about that in our guide to calorie counting.
How long does it take to lose weight?
That depends on your goal and your chosen deficit. Here is a realistic overview.
| Weight loss goal | With -300 kcal/day | With -500 kcal/day |
|---|---|---|
| 3 kg | ~10 weeks | ~6 weeks |
| 5 kg | ~17 weeks | ~10 weeks |
| 10 kg | ~33 weeks | ~20 weeks |
These estimates do not account for metabolic adaptation. In practice, it may take slightly longer, especially as you lose more weight. Also expect plateaus -- periods where your weight stalls temporarily despite a consistent deficit. That is normal and not a reason to take drastic measures.
After reaching your target weight, it is important to gradually increase your calorie intake to your maintenance level. Abruptly returning to your old eating pattern often leads to the yo-yo effect. Read more about this approach in our article on reverse dieting.
Sources
- Voedingscentrum — Losing weight with healthy food (Dutch Nutrition Centre)
- Voedingscentrum — Does calorie counting help with weight loss? (Dutch Nutrition Centre)
- ISSN — Position Stand: Protein and Exercise (2017)
Start losing weight responsibly today
Weight loss does not need to be extreme. A calorie deficit of 300 to 500 kcal per day, combined with adequate protein and regular exercise, delivers sustainable results. It starts with knowing how much you eat.
Want insight into your calorie intake without the hassle? With Moveno, you take a photo of your meal and instantly see the nutritional values. So you know exactly where you stand -- every day. Discover how it works.
