Body recomposition: building muscle and losing fat, and who it works for

What does body recomposition mean?

Body recomposition means changing your body composition: more muscle and less body fat, within the same phase. In a classic diet, you want to lose weight. In a classic building phase, you want to gain it. In a recomposition, body weight is not the goal. The aim is to shift the ratio of muscle to fat.

That has a consequence many people underestimate: fat loss lowers your weight, muscle gain raises it. The two can cancel each other out. So the scale can stay almost the same for weeks while your body visibly changes. If you don't know that, it's easy to mistake real progress for a standstill.

Who does body recomposition work for?

It works best for people whose bodies still respond strongly to training: beginners, people coming back after a break, and people with a fairly high body fat percentage. For them, muscle gain and fat loss overlap comparatively well.

For a long time, recomposition was seen as something only beginners or people with overweight could pull off. A review shows, however, that it has been observed repeatedly in trained people too. The two most important requirements were progressive strength training and a diet to match (Barakat et al., 2020). So it's possible for advanced trainees as well, just much more slowly.

The more of the top three rows apply to you, the more a recomposition is worth it. The clearer your priority, the more a specialised phase is worth it.

How many calories do you need for a recomposition?

Slightly fewer than you burn: a small deficit of around 10 percent. With a total expenditure of 2,000 to 3,000 kcal, that's 200 to 300 kcal a day. If you're unsure where you stand, maintenance calories are the most cautious option. A small surplus can make sense for true beginners, but it shifts the focus towards building.

Why not a bigger deficit? A meta-analysis compared strength training with and without an energy deficit. In a deficit, strength went up about as well, but the gain in lean mass was smaller. From a deficit of around 500 kcal a day, it disappeared completely on paper (Murphy & Koehler, 2022). For a recomposition, that means the deficit has to stay small. Otherwise it turns into a normal diet.

An example with real numbers: a woman, 30, 168 cm, 72 kg (159 lb), lightly active daily life, strength training three times a week. Her basal metabolic rate according to Mifflin-St Jeor is 1,459 kcal, and her total expenditure is around 2,080 kcal. This is how the three goals look in the calorie calculator:

At around 210 kcal, the recomposition deficit sits right in the small range. The 0.19 kg per week is a pure fat calculation. If she builds muscle at the same time, her weight drops even more slowly, and in some cases not at all. In a recomposition, that is what you want.

How much protein do you need?

The same as in every other phase: 2.0 g of protein per kilo of body weight, whether you're currently eating in a small deficit, at maintenance or slightly above. If you're significantly overweight, the calculator uses your goal weight instead of your current weight.

A study of young men shows how much protein can matter in a deficit. For four weeks, they ate around 40 percent below their needs and trained very intensely six times a week. The group on 2.4 g of protein per kilo gained an average of 1.2 kg of lean mass and lost 4.8 kg of fat. The group on 1.2 g gained only 0.1 kg of lean mass and lost 3.5 kg of fat (Longland et al., 2016). That was a tightly controlled programme with a very high training load, not a template for your everyday life. But it shows that you shouldn't skimp on protein in a deficit. The 2.4 g in that study went with a 40 percent deficit. For the small deficit of a recomposition, it stays at 2.0 g. How to work out your needs and spread them across the day is covered in the article on protein requirements.

No progression in training, no recomposition

Training is the part that triggers muscle growth in the first place. In a recomposition, you don't have the calorie surplus that gives building phases an extra push. That makes every single training stimulus count for more.

• Close to failure: In your key exercises, regularly train so that only a few reps would be left at the end of the set. How to judge that is explained in the article on RIR in strength training.
• Well-chosen sets: Pick the right ones and focus on compound exercises.
• Track your progression: Write down weight and reps so you can see over the weeks whether you're getting stronger.
• Plan your recovery: Sleep and rest between sessions are part of it. Too much stimulus without recovery brings no adaptation.

My clear opinion: if you just train “somehow” during a recomposition, you're really doing a slow diet. Without rising performance, the signal to build muscle is missing.

How to tell if it's working

Not from the scale alone. It only shows the total, not whether fat has gone down and muscle has gone up. Three signals that you record regularly are more reliable:

• Measurements of your waist, arms and legs, taken every two weeks at the same spots.
• Photos every four weeks, in the same light, at the same time of day and in the same pose.
• Strength numbers in your main exercises, every training week.

Don't compare one week with the next. Compare periods of three to four weeks. If your performance goes up and your body changes, everything is going to plan. If neither moves over that period, check calories, training and recovery one by one and change only one variable. How to set up each measurement properly is covered in the article Measuring progress without a scale: waist, photos, strength.

When a diet or a building phase fits better

A recomposition is usually a time-limited phase. Give it a fixed time frame of eight to twelve weeks, then take an honest look at where you're furthest behind.

If your body fat is still far from your goal while your muscle and strength are stable, a pure diet phase with a somewhat larger deficit will get you further. If your body fat is already in your target range and you mainly want to gain muscle and strength, a building phase with a small surplus is the clearer route. If all three signals keep moving in the right direction, simply carry on as you are.