Improving body composition means shifting the ratio of fat to muscle in your body, and it comes down to three levers: how you eat, how you train, and how consistently you do both. The good news is that most people, regardless of starting point, can make meaningful changes within a few months. Expect to lose roughly 1% to 3% of your body fat per month with a solid plan in place.
Unlike simple weight loss, body composition improvement focuses on preserving or building muscle while reducing fat. That distinction matters because two people at the same weight can look and feel completely different depending on how much of that weight is muscle versus fat.
What “Good” Body Composition Looks Like
There’s no single agreed-upon standard for healthy body fat, but a large 2025 study using U.S. national survey data offers useful benchmarks. It classified “overweight” as body fat of 25% or higher for men and 36% or higher for women. “Obesity” started at 30% for men and 42% for women. These aren’t perfect cutoffs, but they give you a general sense of where the health risks start climbing.
Most men pursuing a lean, athletic look aim for somewhere between 12% and 20% body fat. For women, that range is typically 20% to 30%. Going much lower than those ranges requires serious dietary discipline and often isn’t sustainable long-term. The practical goal for most people isn’t hitting a specific number but steadily moving in the right direction while feeling strong and energetic.
Can You Lose Fat and Build Muscle at the Same Time?
Yes, and this process, often called body recomposition, is more achievable than many people think. The old idea that you must bulk (gain muscle with some fat) and then cut (lose fat while hoping to keep muscle) in separate phases isn’t the only path forward.
If you’re relatively new to resistance training, you’re in the best position to recompose. Beginners respond so strongly to the new stimulus of lifting weights that they can add muscle even while eating in a caloric deficit. People carrying excess body fat also have an advantage here because their bodies have more stored energy available to fuel muscle growth.
What’s more encouraging is that research has demonstrated body recomposition in trained individuals too, not just beginners. Multiple randomized controlled trials show that experienced lifters can gain muscle and lose fat simultaneously, particularly when protein intake is high. One interesting finding: even in studies where trained subjects ate slightly more calories than they burned, they still lost fat when the surplus came specifically from protein. That said, the effect becomes harder to achieve the more advanced you get. Competitive physique athletes in contest preparation rarely manage it.
Set Your Protein Intake First
Of all the dietary changes you can make, increasing protein has the largest single impact on body composition. Protein does three things at once: it provides the raw material your muscles need to grow, it keeps you fuller for longer than carbs or fat, and your body burns more calories digesting it than any other macronutrient.
The American College of Sports Medicine recommends 1.2 to 1.7 grams of protein per kilogram of body weight per day for people who exercise regularly. For a 170-pound (77 kg) person, that works out to roughly 92 to 131 grams daily. If you’re actively trying to lose fat while training hard, aim for the higher end of that range. Spread your intake across three to four meals rather than loading it all into one sitting, since your body can only use so much protein for muscle building in a single meal.
You don’t need to obsess over the rest of your diet, but a few principles help. Fill most of your plate with whole foods: vegetables, fruits, lean proteins, whole grains, and healthy fats. These are more filling per calorie than processed alternatives, which makes staying in a moderate deficit much easier without constant hunger.
Lose Fat at the Right Speed
Losing weight too quickly is one of the most common mistakes people make when trying to improve body composition. Aggressive diets that drop pounds fast also strip away muscle, which is the opposite of what you want. Aiming for 1 to 2 pounds of weight loss per week lets you preserve and even build muscle when you pair it with resistance training and adequate protein.
In practical terms, this means a caloric deficit of roughly 500 to 1,000 calories per day, achieved through some combination of eating less and moving more. You don’t need to count every calorie if that doesn’t suit you. Tracking portions loosely, cutting liquid calories, and eating more protein and vegetables often creates enough of a deficit naturally. The scale should trend downward slowly. If your weight is dropping faster than 2 pounds per week for multiple weeks in a row, you’re likely losing muscle along with the fat.
Prioritize Resistance Training
Lifting weights (or doing other forms of resistance training like bodyweight exercises or resistance bands) is non-negotiable for improving body composition. Cardio burns calories, but resistance training is what signals your body to build and keep muscle tissue. Without it, a caloric deficit will pull from both fat and muscle stores indiscriminately.
The research on training volume is clear: you need at least 10 sets per muscle group per week to maximize muscle growth. Doing 2 to 3 sets per exercise produces about 40% more growth than doing just one set. So a simple, effective approach is to perform 3 to 4 exercises per muscle group across the week, doing 3 sets of each.
How often you train matters less than your total weekly volume. Training a muscle group twice per week isn’t inherently better than once per week if the total number of sets is the same. However, splitting your volume across more sessions makes it easier to accumulate enough work without exhausting yourself in a single workout. Most people do well with three to five resistance training sessions per week, hitting each major muscle group at least twice.
Progressive overload is the engine that drives results. This means gradually increasing the challenge over time: adding small amounts of weight, doing an extra rep, or performing one more set. If your workouts stay exactly the same for months, your body has no reason to adapt further.
Use Cardio Strategically
Cardio supports fat loss by burning extra calories, but the type you choose affects your body composition differently. High-intensity interval training (short bursts of hard effort followed by rest) burns more total calories in less time and continues burning calories at an elevated rate for hours afterward as your body recovers. It also engages fast-twitch muscle fibers, which helps preserve or even build muscle.
Low-intensity steady-state cardio (walking, easy cycling, light jogging) burns a higher percentage of fat during the activity itself, though the total calorie burn is lower. Its main advantages are that it’s easier to recover from, doesn’t interfere with your strength training, and can reduce stress hormone levels over time.
The best approach for body composition is to use both. Two to three short high-intensity sessions per week (15 to 25 minutes each) paired with daily walking or other low-intensity movement gives you calorie-burning benefits without overtaxing your recovery. Keep cardio volume moderate. Excessive endurance training can interfere with muscle growth, especially if you’re eating in a deficit.
Sleep and Recovery Matter More Than You Think
Sleep deprivation shifts your body’s hormonal environment in exactly the wrong direction for body composition. It increases hunger hormones, decreases the hormones that signal fullness, reduces insulin sensitivity, and impairs your body’s ability to recover from training. Studies consistently show that people who sleep fewer than six hours a night lose more muscle and less fat during a diet compared to those sleeping seven to nine hours.
Chronic stress has a similar effect. Elevated stress hormones promote fat storage, particularly around the midsection, and can break down muscle tissue. Regular physical activity helps manage stress, but so do the basics: adequate sleep, social connection, time outdoors, and not living in a constant caloric deficit for months on end. If you’ve been dieting for 12 or more weeks, taking a planned break at maintenance calories for a few weeks can help normalize your hormones and set you up for better results when you resume.
How to Track Your Progress
The bathroom scale is a poor tool for tracking body composition because it can’t tell you whether changes come from fat, muscle, water, or food in your digestive system. A better approach combines multiple measures.
DEXA scans are considered the gold standard for measuring body fat and lean mass. They’re available at many medical offices and specialized body composition clinics, typically costing $40 to $100 per scan. Bioelectrical impedance scales (the kind you stand on at home or at the gym) are less accurate. Compared to DEXA, they tend to underestimate fat mass by about 1.8 kg (4 pounds) and overestimate lean mass by about 2.6 kg (5.7 pounds). They’re still useful for tracking trends over time, as long as you measure under consistent conditions: same time of day, same hydration status.
Simpler methods work well too. Progress photos taken monthly in the same lighting and poses reveal changes that neither the scale nor the mirror show day to day. A tape measure around your waist, hips, chest, and arms provides objective data. And how your clothes fit is an underrated metric. If your pants are looser at the waist but your shirt sleeves feel tighter, your composition is moving in the right direction regardless of what the scale says.
Give any approach at least 8 to 12 weeks before judging results. Body composition changes slowly, and the first few weeks of any new program involve water shifts, inflammation from new training, and other noise that masks the real signal underneath.