Want To Age Well? Track Your Body Composition

When it comes to health, many of us are conditioned to zero in on the number we see on the scale. But weight is really just one piece of the puzzle—and hardly the most important. In fact, experts are increasingly emphasizing other metrics as more compelling indicators of our health, especially as we age. One of these? Body composition.

Here’s what body composition can tell you about your overall well-being—and what insights it can offer about your quality of life as you blow out more birthday candles. Plus, experts share how you can achieve (and maintain!) the healthiest body composition possible to promote vigor and vitality for decades to come.

• ABOUT OUR EXPERTS: Amie Dworecki, B.S., M.A., M.B.A., is a trainer and longevity coach. Reda Elmardi, R.D., C.S.C.S., is a registered dietitian, strength and conditioning specialist, and founder of ActivBuilt. 

All About Body Composition

Body composition refers to the components that make up a person’s total body weight, including muscle mass, fat mass, bone density, and water content, explains trainer and longevity coach, Amie Dworecki, B.S., M.A., M.B.A. “Unlike weight measurements that sum up everything or BMI calculations that only show weight relative to height, body composition offers a detailed, valuable picture of your health—especially for goals like fat loss or muscle gain,” she says. 

You see, measuring body composition gives you an estimated picture of how much of your total weight comes from healthy muscle and bone versus fat. The breakdown matters for a few reasons. For one, while some fat mass is needed for hormone production and energy storage, too much—especially around our organs (called visceral fat)—can increase inflammation and increase the risk of various health conditions like heart disease and diabetes. Meanwhile, adequate muscle mass is essential for metabolic health (think blood sugar management and keeping excess fat at bay), healthy joints and bones, and your ability to stay active, perform various tasks of daily living, and the like. Finally, solid bone mass and strength prevent independence-altering fractures down the line.

Body Composition And Aging

Maintaining healthy body composition is a good thing at any age—but it becomes increasingly important as the years wear on. “Understanding body composition is crucial because age-related changes can significantly impact athletic and life performance, as well as overall health,”  says Dworecki.

Read More: The Best Foods And Supplements For Longevity

For example, research shows that women, in particular, experience a natural decline in muscle mass and bone density with age, especially after menopause—a change that total weight or BMI alone might not reveal. Two women might weigh 140 pounds and have a BMI of 23, but their body compositions could tell completely different stories, notes Dworecki. “One might have maintained strong muscle mass through consistent strength training and proper nutrition, while the other might have a higher percentage of body fat and less muscle mass, putting her at greater risk for injury,” she explains. Since weight and BMI don’t distinguish between muscle weight and fat weight, they can be seriously misleading—and increasingly unhelpful in helping us understand our bodies as we get older.

Though declines in bone density and strength are often discussed as women’s issues, men are also affected by muscle mass and bone loss as they age. As such, achieving and maintaining a healthy balance between lean (muscle and bone) mass and fat mass is the key to staying strong, resilient, and thriving as you get older—no matter your sex. Keeping an eye on your body composition gives you a more detailed snapshot of what’s happening beneath your skin’s surface—and what lifestyle changes you may want to make to support healthy metabolic function, mobility, and more.

How To Support Healthy Body Composition

Good news: With intention and a little effort, anyone can improve their body composition. In addition to supporting physical health, doing so can also improve energy levels and mental clarity, and even promote greater longevity, according to Dworecki. These lifestyle adjustments have a powerful impact on your balance of muscle, fat, and bone. 

1. Incorporate strength training into your workouts

Exercise for body composition isn’t just about burning calories; it’s about sending the right signals to your body to maintain or build muscle while optimizing fat loss, explains Dworekci. “A well-rounded program should include strength training, such as lifting weights, resistance band workouts, or bodyweight exercises, and cardiovascular exercise,” she says. “Because muscle burns more calories, even when the body is at rest, you score a metabolism boost by efficiently increasing the demands on your muscular system through weight, reps, or complexity of movements.” 

Most experts recommend at least two or three full-body strength training sessions per week. Research shows that strength training as you age helps combat the body’s natural decline in muscle mass and bone density, reducing the risk for conditions like osteoporosis (brittle, weak bones).

2. Try to stay consistently active 

Beyond structured workouts, consistent activity throughout the day and week plays a critical role in maintaining a healthy body composition, according to research published in the Journal of Sport and Health Science. The study found that American adults who incorporated regular physical activity—like walking, hiking, gardening, or even stretching—into their downtime had healthier body fat levels than those who were more sedentary in their free time. 

Incorporating non-exercise activity can be especially beneficial for those with sedentary jobs by counteracting the negative effects of prolonged sitting. Elmardi recommends aiming for at least 7,000 to 10,000 steps per day or the equivalent in active minutes. 

3. Prioritize a high-protein diet

Protein is essential for muscle repair and growth, making it a cornerstone of any healthy body composition plan. Especially when paired with strength training, consuming adequate protein helps preserve lean mass, notes registered dietitian and strength and conditioning specialist Reda Elmardi, R.D., C.S.C.S., founder of ActivBuilt. 

Elmardi recommends aiming for about 0.8 to one gram of protein per pound of body weight daily, depending on your activity level. For someone who weighs 150 pounds, that’s 120 to 150 grams of protein per day. “High-quality sources like lean meats, fish, eggs, beans, and dairy provide amino acids that fuel muscle recovery and satiety, reducing the likelihood of overeating,” he notes. “Spreading your protein intake evenly across meals also maximizes its benefits.” (Here are a few easy ways to pack 30 grams of protein into your next meal.)

4. Keep sugar and processed foods to a minimum 

Research has found that a diet high in ultra-processed foods can sabotage body composition by promoting fat gain and reducing nutrient density. These foods, including sweetened drinks, packaged cakes, ready-made meals, and deli meats, are often calorie-dense but low in essential nutrients like vitamins, minerals, and fiber, leading to overeating and weight gain, explains Elmardi. 

To support healthy body composition for the long haul, focus on whole, minimally processed foods such as fruits, vegetables, whole grains, lean proteins, and healthy fats, Elmardi recommends. This approach not only supports better body composition but also provides the nutrients necessary for energy, muscle recovery, and overall health.

5. Get enough sleep each night

When you fall short on sleep, you can usually feel it. You’re tired, foggy, and less motivated. What you might not notice, though, is that poor sleep influences your body’s hormone production. For example, without ample shut-eye, you produce more of the stress hormone cortisol, which can lead to fat storage, as well as ghrelin, which influences hunger and fullness, Elmardi says. As a result, you might feel hungrier and crave high-calorie, sugary foods—and feel less satisfied after eating. Together, it’s a recipe for fat gain over time.

But that’s not all: Sleep is when your body repairs and builds muscle, according to Elmardi. If you don’t get enough rest, you might lose muscle mass, which is essential for keeping your metabolism running efficiently and your body strong and mobile. “Less muscle means it’s easier to gain fat, even if your weight on the scale doesn’t change much,” he says. 

Take the recommendation of getting seven to nine hours of sleep each night seriously! If rest doesn’t come easily, consider cutting out caffeine after lunch, reading instead of scrolling before bed, and enlisting the help of a sleep-supporting supplement like magnesium glycinate or l-theanine.

6. Measure your body composition every few months

If working on your body composition is a major priority, consider tracking it every three to six months, suggests Dworecki. This frequency allows you to see meaningful changes without getting hung up on short-term fluctuations. “Start with an initial assessment to establish your baseline and then follow up after four to six weeks to catch early progress before settling into a regular schedule,” she says.

How to track your body composition

Keeping tabs on your body composition can be as high- or low-tech as you like. 

DEXA scans (short for Dual-Energy X-ray Absorptiometry) are considered the gold standard and the most accurate way to measure body fat percentage. These scans use two low-energy X-ray beams at different frequencies to pass through your body, showing exactly where your fat and muscle are distributed, explains Dworecki. “While it’s highly accurate, it’s important to note that it’s a medical test, so it’s not something you’ll be able to do weekly in your bathroom like you can with an at-home scale,” she says. You can find them in many functional medical offices, as well as in physical therapy or fitness centers. 

The BOD POD is another gold standard of body composition testing you can find at many gyms and fitness centers, according to Dworecki. It’s shaped like a high-tech egg and uses air displacement plethysmography (ADP) to measure body composition. “It’s like an advanced version of the underwater weighing method, but instead of water, it uses air,” Dworecki explains. “Rather than having to submerge yourself in water (which let’s face it, isn’t everyone’s cup of tea), you simply sit in a comfortable chamber for a few minutes.” 

There are also home “smart” scales that claim to measure everything from body fat to water weight and work by sending a tiny electrical current through your body. (Don’t worry, you can’t feel it.) “While they’re convenient for tracking trends over time, they’re not as precise as medical methods,” warns Dworecki. “They offer more of a rough sketch rather than a detailed photograph of your body composition.”

You can also gauge body composition changes at home by simply monitoring how your clothes feel. A looser or tighter fit in certain areas can indicate fat loss or muscle gain, Dworecki says. For example, a looser fit in the waist typically indicates fat loss around your midsection.

“The mirror test is another go-to; you can look out for signs of muscle definition changes, especially in areas like your shoulders and abs, enhanced muscle contours, more veins showing, firmer muscles, etc.,” she says. “Take monthly photos using the same lighting, at the same time of day, and in the same poses so you can compare the results over time.”

Lastly, you can determine body composition progress using strength indicators. Are everyday tasks, like carrying groceries or lifting your kids or grandkids, getting easier? Are your energy levels higher? These can be telling signs that your overall body composition is improving, according to Dworecki. 

The key is looking for patterns over time rather than day-to-day fluctuations. While these methods won’t give you exact body fat percentages, they can help you track progress effectively and are often more motivating than numbers on a scale.