How to Maintain Muscle Mass While Losing Weight

As a dietitian, I’ve received this question countless times: “How can I lose weight without losing my muscle mass?” It’s a common concern for many people. We all need to maintain our muscles, as they support our bodies in everything we do, from sitting upright to carrying groceries to exercising. 

However, when we’re trying to lose weight, we often worry about losing our precious muscle mass in the process. To address this concern, we consulted two registered dietitians who provide expert-backed tips to help you achieve weight loss without compromising your muscle mass.

How Do You Lose Weight?

There are many factors that can influence our body weight, including things like genetics that are not modifiable. One factor that we can modify is the balance between the amount of calories we consume and the amount of calories we burn. If your goal is to lose weight, you technically need to be in a calorie deficit.

A calorie deficit occurs when you consume fewer calories than your body needs. For example, if you require 2,500 calories per day to maintain your weight, you would need to consume less than 2,500 calories per day to create a deficit. This can be done by reducing your overall calorie intake, increasing your energy expenditure through exercise or doing a combination of both.  

Marie Spano, M.S., RD, CSCS, CSSD, sports dietitian for the Washington Nationals, recommends a balanced approach. She suggests that a person following a 2,500-calorie a day diet could reduce daily calorie intake by 300 calories and increase energy expenditure by 200 through increasing exercise or activities of daily life. You can do this by reducing your intake of calorie-dense foods like sugar-sweetened drinks or packaged sweets that don’t contribute many other nutrients. And increasing physical activity could mean tacking on additional time to your daily walk, jog or hike. Even things like gardening or dancing can add up—just make sure it’s something you actually enjoy so you’re more likely to stick with it. 

Spano cautions against creating too large of a calorie deficit and recommends nothing more than about a 500-calorie per day deficit. She says, “Research shows slower weight loss helps minimize muscle loss and it is easier to maintain.” 

Amy Goodson, RD, sports dietitian and author of The Sports Nutrition Playbook, agrees, and says, “Focus on reducing calorie intake slightly—300 to 500 calories per day—to promote steady fat loss without drastically cutting calories, which can lead to muscle loss and other health issues.”

Remember, while a calorie deficit plays an important role in supporting weight loss, other factors like a person’s diet, exercise regimen, sleep schedule and stress-management techniques also play a role and need to be considered. 

How to Maintain Muscle Mass 

Muscle is primarily composed of protein. It’s essential for building, repairing and maintaining muscle tissue. Unlike fat or carbs, our bodies don’t store large reserves of protein. Therefore, we need to consistently consume protein sources throughout the day to provide our muscles with the necessary building blocks (called amino acids). 

In addition to an adequate intake of protein, engaging in strength training (also known as resistance training) is crucial for building and preserving muscle mass. Both Spano and Goodson recommend incorporating a regular strength-training program into your week to maintain muscle mass. 

Tips for Maintaining Muscle Mass While Losing Weight 

1. Eat More Protein

Eating enough protein, choosing high-quality sources and distributing it evenly throughout the day is essential for maintaining muscle while losing weight. As Spano explains, “Since you need to decrease calorie intake to lose weight, protein intake needs to go up to spare the breakdown of muscle tissue. The greater the caloric deficit, the higher your protein needs to help spare muscle loss during weight loss.”

Goodson agrees, stating that a high-protein diet can help preserve lean muscle mass during weight loss. She recommends consuming approximately 1.5 grams of protein per kilogram of body weight. For a 150-pound person, this translates to about 102 grams of protein per day.

“Distributing protein intake over the course of the day helps provide the body the amino acids it needs to build and repair lean muscle mass,” says Goodson. She recommends about 30 grams of protein at each meal and 8 to 15 grams at snack times. To meet this goal, consider starting your day with a high-protein smoothie. A combination of 1 cup of Greek yogurt (packing 22 grams of protein), 1 cup of dairy milk (8 grams of protein), frozen berries, leafy greens and a spoonful of nut butter can hit over 30 grams of protein per serving and provide you with a balanced and nutrient-rich breakfast. For more recipe inspiration, try one of our high-protein smoothies with at least 15 grams per serving.

Distributing your protein intake throughout the day not only provides your body with necessary amino acids but it also helps promote satiety. This can help you feel full for longer and can help prevent overeating.  

Finally, our experts recommend focusing on high-quality protein options, such as those found in whole foods. And aim to consume a variety of different protein sources to help you best meet your needs. Opt for lean cuts of beef, turkey, chicken, seafood, eggs, dairy products like milk, yogurt and cheese, as well as plant-based proteins like tofu, lentils and beans. 

2. Prioritize Strength Training 

Both Goodson and Spano emphasize the importance of strength training for maintaining muscle mass and facilitating weight loss. Research supports the effectiveness of combining strength training with calorie deficit for weight loss, as it promotes muscle growth while reducing body fat. Muscle is also metabolically active, meaning it requires energy just to maintain itself. Therefore, the more muscle you have, the more calories you burn, even at rest.

Strength training is a form of exercise that burns calories both during and after your workout. Whether you’re lifting weights or using a resistance band, strength training can increase your overall energy expenditure. Additionally, the afterburn effect—also known as excess post-exercise oxygen consumption (EPOC)—continues to burn calories after your workout as your body works to restore its temperature, repair damaged muscle tissues and replenish oxygen levels.

3. Focus on Whole Foods

While counting calories can be a helpful tool in weight loss, it’s hard to realistically do long term. A more sustainable and effective approach is to focus on consuming whole foods. Spano advises, “Eat the majority of your food from whole, less-processed foods while also fitting in your favorite foods so you do not feel deprived.” The key word being majority. We know no one’s diet is going to solely focus on nutrition 100% of the time, and there are many reasons we eat, like personal preference, celebration and socializing. It’s important to be able to build flexibility in your eating pattern and know it’s OK to include less-nutritious foods in moderation too. You can align with your goals and meet your needs by focusing on whole foods the majority of the time, including things like fruits, vegetables, whole grains, healthy fats and lean proteins.

Whole foods are typically more calorie-dense than highly processed foods. Spano explains, “In addition to typically containing fewer calories than their more-processed counterparts, there are a few studies showing we absorb fewer calories from some less-processed foods.”

Spano also emphasizes the importance of a fiber-rich diet, and recommends females aim for 25 grams of fiber per day and males should shoot for 38 grams per day. Research has also found that a high-fiber diet that contains minimally processed foods reduced calorie absorption and resulted in weight loss. (7)

4. Don’t Skip Meals

While achieving a calorie deficit is important for weight loss, it’s crucial to avoid unhealthy strategies like skipping meals or overexercising. As Goodson explains, “Skipping meals can lead to the use of muscle mass as a source of energy, which is counterproductive to maintaining lean muscle.” 

Not to mention, if you’ve ever skipped a meal, do you remember what happens later? You might be more inclined to overeat. Goodson explains, “It can also set people up to feel extremely hungry at the next meal or snack, which can lead to overeating and hindering weight-loss goals.”

The Bottom Line

Losing weight while also maintaining muscle mass is achievable through a moderate calorie deficit, boosting your physical activity and increasing your intake of protein. Prioritize including high-quality protein options like meat, poultry, fish, legumes and dairy in each meal or snack of the day. Dietitians recommend building a majority of your meals around whole foods, and lowering your intake of highly processed foods. They also recommend striving to meet daily fiber recommendations and avoid skipping meals to help preserve muscle mass and support weight-loss goals.