If you don’t use it, you lose it. That’s common wisdom, backed up by science, about what happens to aging muscles.
And if your goal is to lose weight – whether you have obesity or a few pounds to drop – losing muscle can hamper your long-term success. In fact, when you focus too much on losing weight, you may miss the bigger picture.
But it is possible to have the best of both worlds: shifting your body composition to get stronger and leaner. Here’s how.
Muscle Mass Declines With Age
Exactly how much muscle we lose as part of getting older, and when that starts, isn’t clear. But in general, you lose around 3% to 5% per decade starting in your 30s, says Tara Collingwood, MS, RDN, an Orlando-based sports dietitian and personal trainer. “We know that at 50 or 60, we won’t have as much muscle as a 20- or 30-year-old.”
Declining muscle mass makes it harder to stay healthy as you age. It can lead to sarcopenia, a condition marked by a loss of muscle and strength that can put you at risk of falls and fractures at an older age. Falls are the top cause of injury and death from injury for people ages 65 and older, according to the CDC.
“Muscle is the most dynamic tissue in our body,” Adil Ahmed, MD, an assistant professor of orthopedic surgery at Baylor College of Medicine. Muscle protects your bones and joints, and it’s also anti-inflammatory, he says.
As for fat, your body does need some of it. But having too much fat tissue is linked to inflammation and various chronic diseases, researchers note in Reviews in Endocrine and Metabolic Disorders.
Poor muscle mass and strength also hamper your ability to bounce back after injury or surgery. “Muscles that are strong recover remarkably well,” Ahmed says. Muscle strength is also tied to bone mineral density: Stronger muscles make for a stronger skeleton.
The Relationship Between Weight and Muscle
One of the many challenges of weight loss is that you don’t just lose fat. When you weigh yourself and see the scale trend down, this weight loss comes from a combination of water, muscle, and fat.
“You don’t really know what you lost,” Collingwood says. “You just know you lost weight.”
Most people will lose at least a little muscle when they lose weight. Given how important muscle is, you want to minimize that loss, especially if you’re postmenopausal, an older adult, have metabolic disease, or are an athlete, researchers note in the journal Nutrients.
And if you’ve weight cycled (losing and regaining weight), that may be linked to gaining more body fat over time. But that finding, published in Diabetes, Obesity and Metabolism, isn’t consistent across the board, and it shouldn’t discourage you from trying to lose weight if you’ve “yo-yoed” before, other research shows.
You’ll also need the muscle once you’ve reached your weight loss goal.
“If you’re only focused on wanting to get to a certain weight to be happy and not think about it anymore, that’s not necessarily true. You’re in it for the long haul. It’s all about changing your lifestyle,” says Emily Lantz, PhD, an assistant professor in the Nutrition Sciences and Health Behavior Department at the University of Texas Medical Branch.
What You Can Do
Since it’s clear how important muscle is, you’ll want to maintain your muscle mass and improve muscle strength when you lose weight. “Muscle has so many benefits, but especially when it comes to weight loss,” Collingwood says.
Don’t focus only on the scale. “The goal is not just weight loss. It’s altering your body composition rather than looking at the number on the scale,” Ahmed says. “Patients talk to me about this, and I tell them that I don’t care what the scale says or what your total weight loss is. It’s more about what your body is made of.”
Change your approach. Rather than drastically cutting calories and trying to torch more with cardio exercise, consider shifting your focus a bit. These two things matter most for maintaining muscle mass and getting stronger while losing weight, according to a research review published in Advances in Nutrition:
- Getting enough protein within a calorie-reduced diet
- Doing strength training (resistance exercise)
“If your goal is weight loss, be mindful that you’ll probably lose some muscle,” Lantz says. “So it’s an even more important time to incorporate some resistance training and maintaining protein intake,” even when you’re limiting calories.
Eating protein does two things: It gives your muscles what they need and helps you stay fuller, longer. That helps when you’re trying to eat fewer calories, Lantz says.
Strength training puts stress on muscles that causes them to break down a little bit and then grow and get stronger. Muscles are also “more metabolically active than fat,” Lantz says. “When you maintain muscle, you burn more calories than you would if you had a different body composition.”
So how can you achieve each? Here’s what to consider:
Protein’s Role
The amino acids that come from foods are the building blocks of protein. You need them to build your muscles. Lantz recommends taking a meal-based approach to protein, which means aiming to get 25 to 30 grams of protein in each meal, an amount that’s backed by research. Focus on lean food sources of protein, such as eggs, chicken, fish, lean cuts of beef and pork, tofu, beans, and lentils.
Protein isn’t all you need, of course. “Look at your diet as a whole; you also need fruits and vegetables for the vitamins, minerals, and fiber that you don’t get from protein-rich sources,” Lantz says.
Do Your Strength Training
You probably already know that you should do both aerobic exercise and strength training for your health. But you might be tempted to favor cardio for the calorie burn when you’re trying to lose weight.
But strength training is key, and it works hand-in-hand with your diet.
“Protein is necessary to build and maintain muscle. But you can’t just eat more protein and expect bigger muscles, and you can’t just do any exercise and expect to maintain muscle,” Collingwood says. “You have to be targeted toward it.”
That’s where strength training comes in. The CDC recommends doing it at least 2 days per week, targeting your major muscle groups.
You don’t have to do those workouts in a gym. Exercises that use your own body weight – such as pushups, squats, and lunges – may be all you need at first. Hand-held weights or resistance bands can make moves more challenging when you’re ready for that.
Bottom Line
Make sure that you’re building a healthy, resilient body by getting enough protein and making strength training part of your routine. Doing those two things can support healthy weight loss and help your body function and feel its best for years to come.
