Guide · For gym goers
Body recomposition: how to lose fat and build muscle at the same time, and how to know it is working
Body recomposition means losing fat and building muscle at the same time, so your shape changes faster than your weight. Who it works for, what it takes in grams and calories, how to track it with a tape measure, photos and your lifts when the scale will not move, and how long it really takes.
Body recomposition, or a recomp, means losing fat and building muscle at the same time, so your shape changes faster than your weight. It works best for beginners, people returning after a break and people carrying more body fat, and it still works, more slowly, for people who have lifted for years, as long as you lift with progression, eat enough protein, keep calories at maintenance or a small deficit, sleep, and give it months.
Sources for every research number are listed at the bottom.
The short version
- Lift every major muscle group at least twice a week, a little harder over time.
- Eat 1.6 to 2.2 grams of protein per kilogram of bodyweight a day (0.7 to 1 gram per pound).
- Eat at maintenance or about 250 calories under. Deficits of about 500 a day stalled muscle gain on average.
- Sleep 7 to 9 hours.
- Judge it over about three months by your waist, photos, lifts and jeans, never by one morning on the scale.
What is body recomposition, exactly?
Your bodyweight is fat plus everything that is not fat: muscle, water, bone, organs. Most diets chase the total; a recomp goes after the split, which is why it confuses people. Lose 2 kilograms (4.4 pounds) of fat and gain 1 kilogram (2.2 pounds) of muscle and the scale says you lost 1 kilogram. Lose 1 and gain 1 and it says nothing happened, while your waist, your photos and your squat all disagree. The scale is not lying, exactly. It is answering a question you did not ask.
Can you build muscle in a calorie deficit?
Yes, with a catch: the bigger the deficit, the less muscle you build.
It can happen. In a 2016 trial in the American Journal of Clinical Nutrition, 40 young men ate about 40 percent fewer calories than they needed for four weeks while lifting and doing interval training six days a week. Those eating 2.4 grams of protein per kilogram a day (about 1.1 per pound) gained 1.2 kilograms (2.6 pounds) of lean mass and lost 4.8 kilograms (10.6 pounds) of fat. Those eating 1.2 grams (about 0.5 per pound) gained 0.1 kilograms of lean mass and lost 3.5 kilograms (7.7 pounds) of fat.
The catch. Please do not try the 40 percent part at home: those men had their food provided and trained six days a week, which is not most people's Tuesday. A 2022 meta analysis of randomized trials found that lifting in a deficit impaired lean mass gains compared with lifting without one, while strength gains held up. On average, a deficit of about 500 calories a day prevented lean mass gains, and the authors advise anyone lifting to keep muscle while losing weight to stay under that. The smaller the deficit, the better your odds.
Who does a recomp work for?
Most people who lift, but not equally. Best odds first.
Complete beginners. The American College of Sports Medicine's summary of its 2026 position stand on resistance training puts it plainly: the biggest jump in results happens when you go from no resistance training to any resistance training. That head start is what a recomp runs on.
People coming back after a break. In a 2024 trial, untrained adults lifted twice a week and one group took a 10 week break in the middle. In their first five weeks back, their leg press strength and muscle size grew faster than the other group's did in its first five weeks of training, and both groups finished level. Your old training is not gone. It is in storage.
People carrying more body fat. In a 16 week trial, 90 premenopausal women with overweight or obesity ate a reduced calorie diet and exercised daily. Everyone lost weight and fat, but the group getting 30 percent of its calories from protein, half of it from dairy, gained lean tissue, while the group on 15 percent protein with almost no dairy lost lean tissue.
People who have lifted for years. It still works, just slower: a 2020 review in the Strength and Conditioning Journal points to a substantial amount of research showing it in people who already lift. Keep the deficit gentle. In a trial with elite athletes lifting four times a week, the group aiming to lose 0.7 percent of bodyweight a week gained 2.1 percent lean mass, while the group aiming for 1.4 percent gained none.
What does a recomp actually take?
Four things, and they work best together.
1. Lifting that gets harder over time
The 2020 review names progressive resistance training as one of two key factors, next to nutrition, and the American College of Sports Medicine keeps it simple: train all major muscle groups at least 2 days a week, build gradually, and for muscle growth aim for about 10 sets per muscle group a week. Training to failure, machines versus free weights and complex periodization did not consistently change results for the average healthy adult.
In practice: two or three full body sessions a week, the big movements, sets that finish a rep or two short of failure, and a little more weight when you hit the top of your rep range on every set. New to lifting? Our free four week plan has a no gym version of every movement. Cardio is welcome at this party. It just does not get to drive.
2. Protein, every day
A meta analysis of 49 studies with 1,863 people doing resistance training found extra protein stopped adding lean mass beyond about 1.62 grams per kilogram a day (0.73 grams per pound), and in a deficit, the 2016 trial found 2.4 grams beat 1.2. So aim for 1.6 to 2.2 grams per kilogram, or 0.7 to 1 gram per pound: roughly 130 to 180 grams a day for a 180 pound (82 kilogram) person. BryksBuilt sets 1 gram per pound, the top of the range, so a short day still lands inside it.
Our protein calculator splits your number into meals, and our macros guide explains when to base it on your goal weight if you have a lot to lose. If you have kidney disease, ask your doctor, not a website.
3. Calories at maintenance, or a small deficit
Maintenance is what keeps your weight flat. Our default for a recomp is maintenance or 250 calories a day under it: the small deficit BryksBuilt uses for a goal weight up to 10 pounds below today's, and well inside that 500 a day line. Lean and trained? Stay close to maintenance. Carrying more fat? You have more room, but treat 500 as a ceiling, not a target. Our weight loss timeline calculator estimates your maintenance from your size, age, steps and training days.
4. Sleep
Canada's movement guidelines for adults aged 18 to 64 call for 7 to 9 hours of good quality sleep, and a small University of Chicago study shows why it matters here. Ten adults aged 35 to 49 with overweight spent two 14 day stretches on the same diet, about 1,450 calories a day, once with 8.5 hours in bed and once with 5.5. They lost about the same weight both times, 6.6 pounds (3 kilograms) on average, but not the same kind.
With more sleep, 3.1 pounds (1.4 kilograms) of the loss was fat. With less, only 1.3 pounds (0.6 kilograms) was fat, and the fat free mass lost jumped from 3.3 to 5.3 pounds (1.5 to 2.4 kilograms). It was a small, short study, so hold the numbers loosely, but that direction is the opposite of a recomp. Sleep is the cheapest performance enhancer you will ever skip.
How do you track a recomp when the scale barely moves?
Use four signals together, with the scale as a fifth, junior one. When three of them agree, believe them.
| Signal | How often | What a recomp looks like |
|---|---|---|
| Waist | Every two weeks | Slowly getting smaller |
| Progress photos (how to take them) | Every two to four weeks | First against latest: a smaller middle, fuller shoulders and legs |
| Training log | Every session | Weight or reps creeping up |
| Clothes | Whenever you get dressed | Looser at the waist, snugger at the thighs |
| Weekly average weight | Weekly | Flat, or drifting down slowly |
Waist. Use the US National Heart, Lung, and Blood Institute's method: stand, put a tape measure around your middle just above your hipbones, and measure just after you breathe out, at the same time of day every time. A shrinking waist under a steady scale is the signature of a recomp. Looser jeans are the same signal, wearing denim.
Lifts. In the 2022 meta analysis, strength held up in a deficit even when muscle gain slowed, so your log keeps moving when the mirror does not. Several weeks of stalled numbers are your early warning.
The scale, demoted. Weigh in most mornings and watch the weekly average, because any single morning moves with water, salt and the weekend. If the average and your waist both climb week after week, you are eating more than you think. If it drops fast, your deficit is bigger than you meant, and that costs muscle. Home body fat scales: a trend, never a verdict.
How long does a body recomposition take?
Longer than the internet says, and nobody can honestly promise you a rate. The recomp studies above ran for 4 weeks, about 8.5 weeks (the slower athletes) and 16 weeks, with lab equipment doing the measuring, and in the 16 week trial the differences between the groups showed up in weeks 8 to 16. At home, with a tape measure, plan on about three months.
A schedule for checking, not a promise of results:
- Weeks 1 to 4: judge your training log only. Rising lifts and a lazy scale are normal.
- Weeks 4 to 8: add the tape measure and your clothes. You want your waist flat or shrinking.
- Week 12: put your first and latest photos side by side and make the call.
If your waist has not moved by week 12 and your lifts have stalled, change one thing: protein first, then sleep, then move from maintenance to the small deficit, or back to maintenance if your lifts are falling. Give it four more weeks. Checking the mirror every morning will not speed this up. We have tested this extensively.
Who should get advice before starting?
This guide is general information for adults, not medical advice.
- A medical condition, medication that affects your weight or appetite, or kidney disease: talk to your doctor before you change your diet or raise your protein.
- Pregnant, trying to become pregnant or breastfeeding: talk to your care team before cutting calories or starting a new program.
- A calorie target under about 1,200 a day: do not go lower on your own. That is our rule of thumb rather than a law of nature, and a registered dietitian can set a number that fits you.
- A history of disordered eating, or food and body image that feel like they run your life: skip the tracking and talk to someone first. In Canada, the National Eating Disorder Information Centre (NEDIC) runs a national toll free helpline at 1 866 633 4220. In the United States, the ANAD helpline is free at 1 888 375 7767. If you are in crisis or thinking about harming yourself, call or text 988 in Canada or the United States, any time.
Doing a recomp in BryksBuilt
Full disclosure, this is our app.
- Setup: pick Body Recomp as a goal when you sign up and move the goal weight to where you want to be. Calories follow the gap: within a pound of today's weight is maintenance, up to 10 pounds lower is 250 under, more than that is 500 under. Protein is 1 gram per pound. You can type your own calorie number any time in Edit Profile, under Fuel.
- Logging, free: food by search or barcode, and your workouts. Personal records are tracked automatically, and tapping one shows a progression chart and an estimated one rep max.
- Tracking, also free: My Progress has Weight with a seven day average line, Body Stats (the Composition view logs waist, hips, chest, biceps, thigh, calf and body fat, with the change since last time), PRs, and Photos with a side by side Compare view.
- Pro: ask the AI coach why you are not losing weight and it reads your recent workouts, your recent meals and your weight trend before it answers.
A tape measure, a notebook and this page will get you there too. The app just makes the logging fast enough that you keep doing it.
The Transformation Challenge is judged on exactly this
Season One of the BryksBuilt Transformation Challenge runs to December 31, 2026, and it rewards what a recomp produces. The judges score visible change in body composition and posture (40 percent), the consistency and quality of your logged training (25 percent) and nutrition (20 percent), and your story and how sustainable your approach is (15 percent). Weight lost is never a criterion: a weekly weigh in counts toward your consistency score, but the number on it does not. The rules even list extreme calorie restriction, dehydration tactics and rapid weight loss as grounds for disqualification, the opposite of everything on this page.
It is free to enter for members 18 or older, or the age of majority where they live if that is higher, and the real world prizes can only be sent to residents of Canada and the United States. Entries close October 31, 2026 at 11:59 pm Pacific.
Questions people ask
The short answers
Can you lose fat and build muscle at the same time?
Yes. It is called body recomposition, and it works best for beginners, people coming back after a break and people carrying more body fat. A 2020 review also pointed to a substantial amount of research showing it in people who already lift, though for them it is slower. It takes lifting that gets harder over time, enough protein, calories at maintenance or a small deficit, and enough sleep.
Can you build muscle in a calorie deficit?
Yes, if the deficit is small. A 2022 meta analysis found that lifting in a deficit impaired lean mass gains compared with lifting without one, while strength gains held up, and on average a deficit of about 500 calories a day prevented lean mass gains. A 2016 trial showed it can still happen in a steep deficit: young men eating 2.4 grams of protein per kilogram a day gained 1.2 kilograms (2.6 pounds) of lean mass in four weeks, but they trained six days a week on food the researchers provided.
Should I eat at maintenance or in a deficit for a recomp?
Either can work. Maintenance gives you the best odds of building muscle with the slowest fat loss. A small deficit, around 250 calories a day, trades a little muscle gain for a little more fat loss. Stay under a 500 calorie deficit, which is where muscle gain stalled on average in the research. If you are lean and have trained for years, stay at maintenance or lose very slowly.
How much protein do I need for a body recomposition?
About 1.6 to 2.2 grams per kilogram of bodyweight a day, which is 0.7 to 1 gram per pound. A meta analysis of 49 studies found extra protein stopped adding lean mass beyond about 1.62 grams per kilogram, and in a deficit one trial found 2.4 grams per kilogram beat 1.2. BryksBuilt sets 1 gram per pound. If you have kidney disease, ask your doctor first.
How long does a body recomposition take?
Give it about three months before you judge it, and expect it to be slower if you have trained for years. A lab study measured a recomp in four weeks under very strict conditions, and in a 16 week trial in women, the differences between the groups showed up in weeks 8 to 16. At home, check your waist every two weeks and compare your first and latest photos at week 12. Nobody can honestly promise you a rate.
Why is the scale not moving when my clothes fit differently?
Because the scale adds everything up at once. Lose 1 kilogram (2.2 pounds) of fat and gain 1 kilogram of muscle and it reads exactly the same, while your waist shrinks. Water and salt add day to day noise on top. Track your waist, your photos and your lifts, and watch your weekly average weight rather than any single morning.
Does a recomp work if I have been lifting for years?
Yes, but slower and with less room for error. A 2020 review pointed to a substantial amount of research showing recomposition in resistance trained people. Keep the deficit gentle: in one trial, elite athletes aiming to lose 0.7 percent of bodyweight a week gained 2.1 percent lean mass, while those aiming for 1.4 percent a week gained none. Protein matters too: a large meta analysis found protein supplementation was more effective in trained people.
Should I do cardio during a recomp?
Yes, for your health, as long as it does not replace lifting. Canada's movement guidelines for adults aged 18 to 64 call for at least 150 minutes a week of moderate to vigorous aerobic activity plus muscle strengthening at least twice a week. Walking counts. If you lift and do cardio in the same session, lift first while you are fresh.
Where the numbers come from
Every source below was read on the date shown. If one has changed, email support@bryksbuilt.com and we will fix it the same week.
- lida.sport-iat.de/ta/Record/4066252?lng=en: “Despite the lack of standardized terminology, building muscle and losing fat concomitantly has been referred to as body recomposition by practitioners. Although many suggest that this only occurs in untrained/novice and overweight/obese populations, there is a substantial amount of literature demonstrating this body recomposition phenomenon in resistance-trained individuals. Moreover, 2 key factors influencing these adaptations are progressive resistance training coupled with evidence-based nutritional strategies.” (checked October 15, 2026)
- experts.mcmaster.ca/scholarly-works/61719: “During a 4-wk period, we provided hypoenergetic (~40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. ... LBM increased (P < 0.05) in the PRO group (1.2 ± 1.0 kg) and to a greater extent (P < 0.05) compared with the CON group (0.1 ± 1.0 kg). The PRO group had a greater loss of fat mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P < 0.05).” (checked October 15, 2026)
- lida.sport-iat.de/ta/Record/4071991: “Thus, we conducted a systematic review of PubMed and SportDiscus for randomized controlled trials performing RT in an energy deficit (RT+ED) ... Analysis A showed LM gains were impaired in RT+ED vs RT+CON (effect size (ES) = -0.57, p = 0.02), but strength gains were comparable between conditions (ES = -0.31, p = 0.28). ... Finally, our meta-regression demonstrated that an energy deficit of ~500 kcal · day-1 prevented gains in LM. Individuals performing RT to build LM should avoid prolonged energy deficiency, and individuals performing RT to preserve LM during weight loss should avoid energy deficits >500 kcal day-1” (checked October 15, 2026)
- experts.mcmaster.ca/scholarly-works/763612: “Data from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p<0.05) increased changes ... The impact of protein supplementation on gains in FFM was reduced with increasing age (-0.01 kg (-0.02,-0.00), p=0.002) and was more effective in resistance-trained individuals (0.75 kg (0.09, 1.40), p=0.03). Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further RET-induced gains in FFM.” (checked October 15, 2026)
- experts.mcmaster.ca/scholarly-works/61772: “We aimed to determine how daily exercise (resistance and/or aerobic) and a hypoenergetic diet varying in protein and calcium content from dairy foods would affect the composition of weight lost in otherwise healthy, premenopausal, overweight, and obese women. Ninety participants were randomized to 3 groups (n = 30/group): high protein, high dairy (HPHD), adequate protein, medium dairy (APMD), and adequate protein, low dairy (APLD) differing in the quantity of total dietary protein and dairy food-source protein consumed: 30 and 15%, 15 and 7.5%, or 15 and <2% of energy, respectively. Body composition was measured by DXA at 0, 8, and 16 wk ... All groups lost body weight (P < 0.05) and fat (P < 0.01); however, fat loss during wk 8-16 was greater in the HPHD group than in the APMD and APLD groups (P < 0.05). The HPHD group gained lean tissue with a greater increase during 8-16 wk than the APMD group, which maintained lean mass and the APLD group, which lost lean mass (P < 0.05). The HPHD group also lost more VAT as assessed by MRI (P < 0.05) and trunk fat as assessed by DXA (P < 0.005) than the APLD group.” (checked October 15, 2026)
- lida.sport-iat.de/ta/Record/4020931?lng=en: “The aim of this study was to compare changes in body composition, strength, and power during a weekly body-weight (BW) loss of 0.7% slow reduction (SR) vs. 1.4% fast reduction (FR). ... All athletes included 4 resistance-training sessions/wk in their usual training regimen. The mean times spent in intervention for SR and FR were 8.5 ± 2.2 and 5.3 ± 0.9 wk, respectively (p < .001). ... LBM increased in SR by 2.1% ± 0.4% (p < .001), whereas it was unchanged in FR (-0.2% ± 0.7%), with significant differences between groups (p < .01).” (checked October 15, 2026)
- jyx.jyu.fi/handle/123456789/97584: “Fifty-five healthy, untrained participants (age 32 ± 5 years) were randomized to periodic (PRT, n = 20 completed the study, 45% females) or continuous (CRT, n = 22 completed the study, 45% females) groups. PRT completed a 10-week RT, a 10-week detraining, and a second identical 10-week RT. CRT began with a 10-week non-RT, followed by a 20-week RT. RT included twice-weekly supervised whole-body RT sessions. ... During the first 5 weeks of retraining in PRT, increases in LP 1RM, and VL and BB CSA were greater than in CRT during Weeks 10–15 of their CRT (p < 0.01). PRT and CTR ended up in similar postintervention adaptations, as decreased muscle strength and size during detraining in PRT regained rapidly during retraining.” (checked October 15, 2026)
- acsm.org/wp-content/uploads/2026/03/Resistance-Training-Position-Stand-infographic.pdf: “The biggest jump in results happens when you go from no resistance training to any resistance training. ... Muscle growth (hypertrophy): Aim for higher weekly volume (~10 sets per muscle group) ... Research has found that things like: ... training to momentary muscle failure ... using specific types of equipment (machine vs. free weights) ... complex periodization …did not consistently change results for the average healthy adult. ... Start here: Train all major muscle groups at least 2 days per week and build gradually over time.” (checked October 15, 2026)
- csepguidelines.ca/guidelines/adults-18-64/: “Moderate to vigorous aerobic physical activities such that there is an accumulation of at least 150 minutes per week ... Muscle strengthening activities using major muscle groups at least twice a week ... Getting 7 to 9 hours of good-quality sleep on a regular basis, with consistent bed and wake-up times.” (checked October 15, 2026)
- www.uchicagomedicine.org/forefront/news/sleep-loss-limits-fat-loss: “The study, performed at the University of Chicago's General Clinical Resource Center, followed 10 overweight but healthy volunteers aged 35 to 49 ... Each participant was studied twice: once for 14 days in the laboratory with an 8.5-hour period set aside for sleep, and once for 14 days with only 5.5 hours for sleep. ... The number of calories they consumed, about 1,450 per day, was kept the same. The volunteers lost an average of 6.6 pounds during each 14-day session. During weeks with adequate sleep, they lost 3.1 pounds of fat and 3.3 pounds of fat-free body mass, mostly protein. During the short-sleep weeks, participants lost an average of 1.3 pounds of fat and 5.3 pounds of fat-free mass.” (checked October 15, 2026)
- www.nhlbi.nih.gov/health/heart-healthy-living/healthy-weight: “To correctly measure your waist circumference, stand and place a tape measure around your middle, just above your hipbones. Measure your waist just after you breathe out.” (checked October 15, 2026)
- nedic.ca/: “We operate Canada’s only national toll-free helpline and live chat providing resources, referrals and support to people across Canada either directly or indirectly affected by disordered eating and related concerns. Toll-Free: 1-866-633-4220” (checked October 15, 2026)
- anad.org/get-help/eating-disorders-helpline/: “Our free eating disorders Helpline provides emotional support and referrals. ... Call the ANAD helpline toll-free: 1-888-375-7767” (checked October 15, 2026)
- 988.ca/: “24/7/365 Crisis Support ... A safe space to talk, 24 hours a day, every day of the year. Call 9-8-8 Text 9-8-8” (checked October 15, 2026)
- 988lifeline.org/: “The 988 Lifeline is available 24/7/365. Your conversations are free and confidential. ... Call, text, or chat with a 988 Lifeline counselor for help during difficult moments anytime, day or night.” (checked October 15, 2026)
- bryksbuilt.com/challenges/transformation-2026: “You must be 18 or older, or the age of majority where you live if that is higher. ... Extreme calorie restriction, dehydration tactics and rapid weight loss are grounds for disqualification. ... Entering is free. ... 15 points for a weekly weigh in ... Each judge gives 0 to 10 on four criteria: visible change in body composition and posture (40 percent), consistency and quality of logged training (25 percent), consistency and quality of logged nutrition (20 percent), and the story and how sustainable the approach is (15 percent). ... Judging is on these criteria only, never on weight lost. ... Prizes are sent only to residents of Canada and the United States.” (checked October 15, 2026)
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