How to preserve muscle while losing weight 

Maintaining a healthy weight is central to great health. But many worry that rapid weight loss means losing muscle.  

These concerns have grown among people using or considering GLP‑1s, driven by headlines warning that their weight loss will include significant muscle loss.

But as Medcan’s clinic director of weight management, Dr. David Macklin, explains, “loss of muscle mass is not a consequence of GLP‑1 medication, it’s a consequence of weight loss.”  

It is also a normal, adaptive response that happens when a person loses weight. As body weight decreases, muscle mass adjusts to support a lighter frame. A 250-pound body, for instance, will grow muscle to support a heavier frame. When that same body loses weight, they will lose muscle based on the new weight.

Still, beyond this fact, research shows there are effective ways to preserve muscle mass while losing weight. By prioritizing protein, incorporating resistance exercise and choosing an eating pattern that supports muscle and bone health, you can work toward a healthier weight without sacrificing strength.  

Why preserving muscle during weight loss is important

Muscle is what allows you to move through your day with ease. From climbing stairs and lifting bags to playing with children or grandchildren, muscle strength underpins independence and quality of life.  

By protecting muscle, you are investing in your ability to live the way you want. That might mean bucket-list travels, playing tennis, skiing, or enjoying other hobbies that matter to you, or simply feeling confident in your physical capabilities.  

Preserving muscle also helps support a healthier resting metabolism, which can make long-term weight management more achievable. 

Muscle tissue is metabolically active, which means the more muscle you have, the more calories your body uses, even when you are sitting, working or sleeping. Therefore, losing muscle during weight loss can reduce your resting metabolism, which may make it easier to regain weight over time. 

It’s also important to understand that maintaining muscle is not just about exercise. Eating the right foods, learning healthy habits and adjusting mindset and behavior are all important aspects of maintaining and building strength, and critical aspects of a sustainable, healthy weight loss journey. 

In fact, exercise alone is not an effective weight loss strategy. It should be considered as an important aspect of living a healthy life in general, and a complement to any weight loss plan, for the various benefits of mental wellbeing, strength, and bone and joint health. 

And when it comes to maintaining muscle more specifically, there are four factors – three of which that aren’t exercise – that support your ability to maintain muscle during weight loss. Those four are: 

1. Get the right amount of protein 
2. Eat foods that support muscle and bone health 
3. Engage in resistance and weight-bearing exercise 
4. Align your mindset to your goals and values 

Four strategies for maintaining muscle during weight loss

Get the right amount of protein 

A calorie-reduced diet that does not protect muscles can leave you feeling weaker and less energetic. In contrast, a plan that combines adequate protein with resistance exercise helps preserve muscle mass while you lose weight. This approach supports a healthier metabolism and can make weight management more sustainable. 

Christine Melanson, lead dietitian for Medcan’s Weight Management Program, advises prioritizing protein at each meal as part of a balanced diet to support weight management. Compared to carbohydrates and fat, protein increases satiety to a greater extent, helping you feel full longer after eating. However, keep in mind that protein should not be at the expense of carbohydrates, particularly if you’re engaged in high levels of physical activity 

A moderately higher protein diet helps preserve muscle mass while following a calorie-reduced diet. Protein supports muscle protein synthesis; the process your body uses to repair and build muscle tissue. Getting enough protein from foods such as fish, chicken, beans, and nuts is essential to support this process. 

Although total protein intake per day seems to matter most, consider spreading protein throughout the day rather than concentrating it in one large meal. This may help optimize muscle protein synthesis overall, particularly in older individuals. 

Plus, as you age, a healthy diet becomes even more important to preserve muscle mass and strength. Age-related muscle loss, called sarcopenia, can affect your ability to do simple daily tasks like sitting down in a chair, carrying groceries, or picking up your grandkids. Therefore, eating a high-quality diet – whether you're focused on weight loss or not – throughout adulthood helps guard against sarcopenia at an older age. 

Eat foods that support muscle and bone health 

Beyond protein, the overall quality of your diet matters for muscle health.  

Recent research underscores the importance of eating a high-quality diet throughout adulthood to guard against sarcopenia at an older age. Antioxidant-rich vegetables and fruit, which help protect muscles from inflammation and harmful free radical damage, may be especially beneficial.  

A Mediterranean-style diet, rich in nutritious whole foods such as fruits and vegetables, grains and pulses, may offer anti-inflammatory and antioxidant nutrients that support muscle and bone. Pairing a Mediterranean-style diet with regular exercise may also help to preserve bone density, even during weight loss. These same anti-inflammatory and antioxidant nutrients are thought to play a key role in slowing age-related bone decline and supporting overall body health. 

Engage in resistance and weight-bearing exercise 

Diet is only part of the picture. Regular physical activity, particularly resistance exercises, can help protect muscle mass while losing weight and support a healthy metabolism. Strength-focused workouts do not just build muscle; they support mobility, stability, and long-term health. 

Weight-bearing exercise is one of the most effective ways to counteract the loss of muscle mass and bone density that occurs with age and life transitions such as menopause. Resistance training and strength-focused workouts help maintain strength and resilience through midlife and beyond. 

Research suggests that women who engage in strength training at least two times a week are more likely to live longer and have a reduced risk of cardiovascular-related events. Strength training is also key to supporting healthy weight management, since it helps reduce fat, not muscle mass. 

Align your mindset to your goals and values 

Mindset and behavior change are a critical factor, too, because it is what allows you to want to eat the right foods and do those resistance exercises regularly to get results. 

Dr. Macklin emphasizes the importance of aligning lifestyle changes with your personal values. “When behaviours are rooted in meaning, you are more likely to sustain them,” he explains. If your goal is to live a healthier life, for example, you are more likely to choose physical activities and nourishing foods that energize you. 

By making this connection, you reinforce how positive choices support your well-being. Exercise, for example, should not be about getting smaller. It should be about getting stronger. When you focus on strength, energy and resilience, preserving muscle becomes a natural and motivating part of your weight loss journey. 

Four practical steps to put these strategies into action  

Step 1: Prioritise protein at every meal 

Make protein the anchor of your meals and snacks to support muscle and help you feel satisfied on a calorie-reduced diet. Aim to include a source of protein whenever you eat, such as: 

• Fish or chicken 
• Beans, lentils or pulses 
• Nuts and seeds 
• Other protein-rich foods that fit your preferences such as milk, Greek yogurt, and cottage cheese 

Protein helps increase satiety compared to carbohydrates and fat, which can reduce the urge to overeat and support weight management. If you are unsure how much protein is right for you, a registered dietitian, such as one of our specialists inside Medcan’s Weight Management & Nutrition Programs, can help you incorporate it into your meals in a way that fits your lifestyle and goals. 

According to Christine Melanson, “Individual protein needs vary depending on age, size and activity level. However, aiming for 20-40 grams of good quality protein with meals, and 10-15 grams with snacks will meet the needs of most individuals.” 

“Individual protein needs vary depending on age, size and activity level. However, aiming for 20-40 grams of good quality protein with meals, and 10-15 grams with snacks will meet the needs of most individuals.” 

Christine Melanson, lead dietitian for Medcan's Weight Management Progam