Do You Need a Certain Body Fat Percentage to Build Lean Muscle Mass?

The decision to start building more lean muscle mass can be an easy one. After all, "adequate lean muscle mass can help with injury prevention, mobility, fall prevention and overall quality of life," says Marisa Michael, RDN, CPT, dietitian, personal trainer and owner of Real Nutrition in the Portland, Oregon area.

But knowing ‌how‌ to get started may not be as intuitive. To begin with, you may wonder, "Do I need a certain amount of body fat to build muscle?"

A high body fat percentage puts you at greater risk for obesity-related illnesses like type 2 diabetes and heart disease, whether or not you're actually overweight. (Ever hear of skinny fat?)

That's the primary concern, naturally, but there's also this: Excess fat forms a layer over your muscles that obscures definition and prevents you from looking toned.

So, how much is "excess?" Chicago-based Emily Hutchins, CPT, a certified personal trainer with RSP Nutrition, says that it's "very subjective to height, weight and activity level," but that approximately speaking, muscle definition in the female body is obscured at 22 percent; in men, 17 percent.

You don't need to be at any particular body fat percentage to start building muscle mass. That said, building lean mass requires a two-pronged strategy: a diet that supports muscle growth, and strength training.

Support muscle building with a protein-rich diet. It should also supply high-quality fats (olive oil and avocados, for example) and carbohydrates (such as whole-grain bread, beans and fruit), since your body will need fat and carbohydrates as fuel for your workouts.

Protein, meanwhile, contains amino acids, which your body uses to build muscle. Your daily protein need while on a plan to build lean muscle mass is 0.5 to 0.8 grams per pound of body weight, according to the American College of Sports Medicine. So, for example, a 150-pound person should aim for between 75 and 120 grams of protein each day.

Foods that have relatively high concentrations of protein include meat, poultry, fish, legumes, tofu, eggs, nuts, seeds, cheese and yogurt.

Those basic guidelines stay the same regardless of your target calorie intake. Calories do matter, though.

"More important than macro splits or nutrient timing, eating enough overall calories will help you get toward your goal," says Michael. "Your body needs fuel to help build up new muscle tissue. If you aren't eating enough, you won't be able to see the gains you are hoping for."

Losing fat and gaining muscle at the same time is tricky to do, Michael tells LIVESTRONG.com. "Building lean mass takes a calorie surplus in order for the body to have available energy to build the new muscle tissue. But shedding body fat requires a calorie deficit."

If you're overweight, then, you may want to focus on losing body fat before trying to build lean muscle mass. Take the number of calories you need to maintain your weight and subtract 500 to 1,000. Eating that reduced number of calories per day can help you lose 1 to 2 pounds a week, according to the Mayo Clinic. If you have a lot of weight to lose, check in with your doctor to come up with the best plan of attack.

Doing resistance exercises can cause an increase in muscle mass no matter how much you weigh, as a November 2016 review of the research in ‌Sports Medicine‌ bore out‌.‌

Muscle loss is normal as we age. But there's good news: Regular resistance exercise while dieting might prevent muscle loss, or even increase muscle mass in adults with overweight (in conjunction with a a high-protein diet), per a February 2017 paper in ‌Nutrition Journal‌.

Plan for two or three weight training workouts weekly. Do large compound exercises, like lunges and bench presses, using weights that feel challenging after eight to 12 repetitions. You'll know it's time to increase the weight when you can perform 12 repetitions without muscle fatigue.

Gradually amp up your workout volume — reps and sets — as your strength and endurance improve, says Hutchins. Keep in mind that as you continue to progress, your gains may well come slower. That's normal, so don't get discouraged.

Recovery is important as well. "Without proper amounts of recovery between workouts, or focusing on flexibility and mobility, the body loses time to repair itself and progression becomes hindered," Hutchins says.

If you're overweight, ask your doctor whether adding cardio to your routine could help you reach your fitness goal. Start with 150 minutes of moderate-intensity cardio weekly — the amount recommended for weight maintenance, according to the Centers for Disease Control and Prevention (CDC) — and gradually increase the length of your workouts as you gain stamina. Examples of moderate-intensity activities include recreational biking, brisk walking and raking leaves.

As your fitness level increases, challenge yourself to higher-intensity workouts (such as jogging, swimming laps and cross-country skiing), which burn more calories per session than moderate-intensity workouts and also burn more fat.

Remember: While the CDC notes that most weight loss occurs because of decreased caloric intake, evidence shows the only way to ‌maintain‌ weight loss is with regular physical activity.

Some people have an easier time putting on muscle than others; if you're a "hard gainer" who resists adding lean mass, you might need personalized help from a certified personal trainer to get the results you want.

On the other hand, if you have overweight or obesity, a doctor or registered dietitian can help you craft a nutrition plan to safely accelerate your results.

Lastly, it's always a good idea to touch base with your physician before jumping into a new diet and exercise program.