Calorie deficit: how to lose weight healthily and sustainably

Whether low carb, intermittent fasting or the latest trend diet: in the end, all weight-loss strategies work on the same principle. You only lose body fat if you take in less energy than your body uses over a longer period. This calorie deficit is the physical basis of every weight loss, no matter what the nutrition concept is called.

That sounds simple, but in everyday life it is often a challenge. A deficit that is too small brings few visible results, while one that is too large makes you hungry and tired and, in the worst case, costs valuable muscle mass. The key therefore lies in a well-dosed deficit that you can keep up for weeks and months.

In this article we explain how to roughly estimate your calorie needs, how large your deficit should be and why training and protein play a central role.

What is a calorie deficit?

Your body needs energy every day: for breathing, heartbeat, digestion and body temperature, but also for every movement. This energy is measured in kilocalories (kcal). If you consume fewer calories through food than you use, a deficit arises. To close the gap, your body draws on its energy reserves, ideally mainly on fat tissue.

Your calorie needs are made up as follows

• Basal metabolic rate: the energy your body needs at complete rest. It makes up the largest part of your energy use.
• Everyday movement: walking, climbing stairs, housework, standing at work. This share is often underestimated.
• Training: targeted physical activity such as strength training, running or group classes.
• Digestion: processing food also uses energy, especially with protein-rich meals.

How to calculate your calorie deficit

Online calculators estimate your total energy use based on age, height, weight, sex and activity level. These values are always approximations. Use them as a starting point and then observe how your weight develops over two to three weeks.

A guideline for a moderate calorie deficit is about 300 to 500 kcal per day below your total energy use. This makes a loss of around 0.5 percent of body weight per week realistic. It may seem slow, but it is far more sustainable than radical diets.

Why a deficit that is too large is counterproductive

Very low calorie intakes often lead to intense cravings, bad mood, concentration problems and reduced performance in training. In addition, the risk of losing muscle and not getting enough micronutrients increases. Your immune defences can also suffer from too little supply. We have already shown you how you can strengthen your immune system. And after the end of a crash diet, the kilos often return quickly.

Preserving muscle: training and protein

A calorie deficit only tells you that you are losing weight, not what you are losing. To make sure it is mainly fat and not muscle, you need two things: strength training and sufficient protein.

Strength training signals to your body that the muscles are still needed. At the same time, more muscle mass raises your basal metabolic rate in the long term. If you are just starting out, our training plan for beginners can help you with a structured start. You can also read why muscle training is so effective for losing weight in the article Losing weight with muscle training.

Protein keeps you full, protects your muscles and has a comparatively high energy cost during digestion. A commonly cited guideline for active people in a deficit is about 1.6 to 2 grams of protein per kilogram of body weight. You can find out which foods are particularly suitable in our overview of protein-rich foods.

8 tips for a calorie deficit without hunger

With these strategies, the deficit will be noticeably easier to manage in everyday life:

1. Focus on volume: vegetables, salad and fruit provide a lot of bulk for few calories.
2. Plan protein into every meal, for example yoghurt, legumes, eggs, fish or tofu.
3. Drink calorie-free: sugary drinks, juices and alcohol quickly provide many calories without making you full.
4. Watch out for hidden fats in sauces, dressings and ready-made products.
5. Eat consciously and slowly, so that your feeling of fullness kicks in in time.
6. Move more in everyday life: additional steps noticeably increase your energy use.
7. Sleep enough, because lack of sleep can intensify hunger and cravings.
8. Plan flexibly: a restaurant visit or a piece of cake does not ruin your progress; what matters is the average over the week.

Common mistakes when losing weight

Many people give up because the scales do not respond immediately. However, body weight fluctuates daily, for example due to water retention, salt or digestion. It is therefore better to weigh yourself regularly under the same conditions and look at the trend over several weeks. Body measurements or how your favourite trousers feel are also good indicators.

Another mistake is creating the deficit exclusively through endurance sport while neglecting strength training. The best results come from a combination of a moderate deficit, strength training and more movement in everyday life.

Frequently asked questions

How long should I stay in a calorie deficit?

That depends on your goal. Many people manage well with phases of a few weeks to months. In between, also plan phases in which you eat at your maintenance level.

Do I have to count calories?

Not necessarily. Tracking calories for a few weeks can, however, give you a good feeling for portion sizes. After that, simple rules such as eating more vegetables and protein are often enough.

Can I build muscle in a deficit?

Especially beginners can build muscle even in a moderate deficit with targeted strength training and enough protein.

Conclusion: your calorie deficit with common sense

A calorie deficit is the basis for any fat loss. What matters is that it is moderate, fits your everyday life and is combined with strength training and sufficient protein. This way you lose fat, keep your muscles and stay fit. If you have pre-existing conditions or special dietary needs, seek advice from a doctor or nutrition professional.

Want to tackle your weight-loss goal with a suitable training plan? In the free trial workout at update Fitness, a coach defines your goal with you and puts together a training plan that optimally supports your calorie deficit.