Yes, you can lose fat and build muscle at the same time. It's called body recomposition. It happens most in people who are new to lifting and people with more body fat to lose. If you've lifted for years and you're already lean, it can still happen, but the changes are usually small.
Recomposition takes three things together: lifting with progressive overload, eating plenty of protein, and keeping your calories at maintenance or a little below. A 2026 review in the Journal of the International Society of Sports Nutrition found lifting plus higher protein to be the most consistent strategy, paired with a modest calorie deficit.
Who it works best for
The 2026 review found the effects were largest in untrained people and people with more body fat, and smaller in trained or lean athletes. It also found recomposition is still possible in older adults with supervised training and enough protein.
Beginners have the most room to change on both sides: more muscle to gain and, often, more fat to lose. A 2022 review of 65 trials in adults with overweight or obesity found that resistance training lowered fat by about 3.5 lb (1.6 kg) and raised lean mass by about 1.8 lb (0.8 kg) on average. People who started with more fat tended to lose more of it.
The same review found that when programs added calorie restriction, lean mass went down. So in these studies, people gained lean mass while losing fat when they lifted without cutting their calories hard. A big deficit with lifting mostly helped them keep the muscle they had.
What about experienced lifters?
It happens, just less. A small 2026 trial followed young adults who had lifted for about a year and a half, mostly men, through the same 4-day lifting plan for 10 weeks. Both diet groups ate high protein. One ate at maintenance and the other ate 250 calories a day below it.
| Group | Fat change | Lean mass change |
|---|---|---|
| Maintenance calories | -3.1 lb (-1.4 kg) | +2.1 lb (+1.0 kg) |
| 250 calories a day below maintenance | -6.5 lb (-2.9 kg) | +2.3 lb (+1.0 kg) |
Both groups gained about the same lean mass. The deficit group lost more fat on average, but the study was too small to show that the difference between the groups was real. These lifters also started at about 25% body fat, so they had fat to lose. A 2020 review by Barakat and colleagues argues that a good amount of research shows recomposition in trained lifters. The 2026 review adds that the changes are usually modest once you're trained and lean.
How big a deficit?
A small one. A 2022 meta-analysis found that lifting in a calorie deficit led to smaller lean mass gains than lifting at maintenance, and a deficit of about 500 calories a day stopped lean mass gains altogether. Strength gains held up either way.
That leaves two options. You can eat around maintenance, where fat comes off more slowly. Or you can eat a little below it, like the 250 calories a day in the trial above, where fat comes off faster and lean mass can still go up. Our free Macro, TDEE & BMR Calculator shows your maintenance calories when you pick "Maintain."
How much protein?
The 2026 review found intakes of about 0.7 to 1.1 grams per pound of body weight a day (1.6 to 2.4 g/kg) were the most consistent, with more toward the top end when you're eating less or already lean. The International Society of Sports Nutrition's 2026 position stand on weight loss diets puts it at about 0.7 to 1.0 grams per pound (1.6 to 2.2 g/kg) with resistance training, and about 0.85 to 1.45 grams per pound (1.9 to 3.2 g/kg) for lean, trained lifters eating in a deficit.
For a 180 lb person, 0.7 to 1.1 grams per pound works out to about 125 to 200 grams of protein a day. Our Protein Calculator works it out for your weight, and our list of high-protein foods shows how much is in everyday foods. For more, see How much protein do I need a day?
How to train
Lifting gives your body a reason to keep its muscle and build more while you lose fat. The American College of Sports Medicine's 2026 position stand found muscle growth was greater with higher training volume, 10 or more sets a week, and strength was greater with 2 or more sessions a week. Adding weight or reps over time keeps the work hard enough to drive progress.
For how much to do, see How many sets per week to build muscle? and How many days a week to work out? If you're new to lifting, our beginner gym workout plan is a good place to start.
Sleep
A 2018 trial had adults with overweight diet for 8 weeks. One group also cut about an hour of sleep on 5 nights a week. Both groups lost about the same amount of weight, but the group that slept less lost a smaller share of it as fat.
How to tell if it's working
Your scale weight may barely move, since you're losing fat and gaining lean mass at the same time. The 2026 review suggests checking body composition and performance from time to time, not only your weight. A few ways to do that at home:
- Your lifts go up over the weeks.
- Your waist measurement goes down.
- Progress photos, taken in the same light every few weeks, show a change.
- Your weekly average weight holds steady or drops slowly. Day-to-day weight swings with water, so the average tells you more.
Common questions
How long does body recomposition take?
In the 2026 trial, lifters lost about 3 to 6.5 lb (1.4 to 2.9 kg) of fat and gained about 2 lb (1 kg) of lean mass in 10 weeks. The 2026 review found bigger changes in beginners and people with more body fat, and smaller ones in lean, trained lifters.
Can you recomp after 40?
Yes. The 2026 review found recomposition is still possible in older adults with supervised, progressive training and enough protein. The 2022 review in adults with overweight found younger adults gained more lean mass than older ones, so changes may come more slowly with age.
Is lean mass the same as muscle?
Not exactly. Lean mass, or fat-free mass, counts everything that isn't fat, including muscle, water, organs and bone. Recomposition studies usually measure it with a DXA scan. A gain in lean mass is a good sign, but not all of it is muscle.
Does it work without lifting?
Not well. In the 2022 review, resistance training is what raised lean mass. The International Society of Sports Nutrition's 2026 position stand calls resistance training and enough protein essential for keeping lean mass while you lose weight.
Sources
- Naddafha S. et al. Body recomposition in adults: mechanisms, modulators, and practical algorithms for simultaneous skeletal muscle mass gain and fat mass loss. Journal of the International Society of Sports Nutrition (2026).
- Barakat C. et al. Body recomposition: can trained individuals build muscle and lose fat at the same time? Strength and Conditioning Journal (2020).
- Vargas-Molina S. et al. Comparison of two nutritional protocols in body re-composition of resistance-trained participants. European Journal of Applied Physiology (2026). (Disclosure: one author has worked with sports supplement companies.)
- Lopez P. et al. Moderators of resistance training effects in overweight and obese adults: a systematic review and meta-analysis. Medicine and Science in Sports and Exercise (2022).
- Murphy C. and Koehler K. Energy deficiency impairs resistance training gains in lean mass but not strength: a meta-analysis and meta-regression. Scandinavian Journal of Medicine and Science in Sports (2022).
- Aragon A.A. et al. International Society of Sports Nutrition position stand: diets for body weight reduction. Journal of the International Society of Sports Nutrition (2026). (Disclosure: several authors consult for nutrition and supplement companies.)
- Currier B.S. et al. American College of Sports Medicine position stand: resistance training prescription for muscle function, hypertrophy, and physical performance in healthy adults. Medicine and Science in Sports and Exercise (2026). (Disclosure: one author formerly advised a fitness equipment company.)
- Wang X. et al. Influence of sleep restriction on weight loss outcomes associated with caloric restriction. Sleep (2018).
