Why you should be tracking your body composition

April 2, 2025
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8
 mins read
WRITTEN BY
Mike Simone
MEDICAL REVIEWED BY
The Prenuvo Medical Group
Summary

Tracking body composition goes far beyond what you see in the mirror. It reveals hidden risks like visceral fat, muscle imbalances, and early organ changes that impact long-term health. A Prenuvo Body Composition Analysis helps people monitor muscle, fat, and organ health over time. It’s especially valuable if you’re using GLP-1 weight-loss drugs, navigating hormonal changes, managing chronic pain, monitoring liver health, planning for pregnancy, or focused on improving health span.

When you hear “body composition” do you immediately think of the muscle and fat you see in the mirror? You’re not wrong, but it does go deeper than that.

When tracking body composition, it’s not just about what you see, it’s about what you don’t see. For example, you can’t see whether you have muscular imbalances in certain areas of the body which can be the hidden cause of pain or leave you more susceptible to injury. You also can’t see how much fat you have deep in the abdominal cavity, something called visceral fat, which is associated with inflammation and metabolic diseases among other conditions. A Prenuvo AI-assisted study found that visceral fat is connected with brain atrophy, in other words: smaller brains. A Prenuvo Body Composition Analysis can help you keep tabs on visceral fat, and as part of your broader MRI report, you’ll find out your brain’s “age” and size.  

“What many people don’t realize about body composition is that it’s a huge biomarker of health, or on the flip side, a biomarker of risk,” says Dr. Jason Itri M.D., P.h.D, an award-winning board-certified radiologist, VP of Body Imaging at Prenuvo, and the owner of Longevity Health Clinic in Charlottesville, Virginia.

“Our body composition report’s biomarkers are really helpful because it gives you quantitative information about where you are with your health and you can follow it over time,” he adds.

Read also: Why tracking your BMI is becoming irrelevant

Here’s five scenarios where tracking your body composition can be very helpful:

1. You’re on a GLP-1 weight loss medication

GLP-1s like semaglutide (Ozempic and Wegovy), Tirzepatide (Mounjaro and Zepbound),  Liraglutide (Saxenda) have exploded in popularity because of their effectiveness, but the weight loss you experience from them comes with some side effects.   

Research has shown that rapid weight loss can lead to significant muscle loss alongside fat loss. A study published in the New England Journal of Medicine found that patients using semaglutide lost an average of 15.3 kg (33.7 lbs), with about 40% of this loss coming from lean body mass. This becomes problematic because the loss of muscle mass can have negative impacts on your metabolism and overall health.

Another unfortunate downsides of rapid weight loss is the potential for bone density loss as well which can increase the risk of fractures. In fact, an analysis of a randomized clinical trial published in JAMA Network Open in 2024, concluded that exercise is important for maintaining bone density while taking GLP1s. 

Getting a Prenuvo Body Composition Analysis every three months is advised to make sure you’re losing weight on the medication but are retaining muscle mass as well.

Equally important is strength training, ideally three days per week, per Dr. Itri: “GLP1s are very effective for weight loss, but you can’t ignore the fact that you need to maintain a fitness routine while on them,” he says. “You need to be doing compound movements like squats and deadlifts because those are the things that are going to build and preserve muscle mass,” he explains. And, if you want to get cardiovascular work in with your weights, Itri says you can use lighter weights for higher repetitions with shorter rest periods to increase heart rate and improve cardiovascular fitness. He also suggests eating about a gram of protein per pound of muscle to ensure you're optimally fueled.

2. You want to stay ahead of aging-related hormonal changes

Women in perimenopause or postmenopause face the challenge of muscle loss and bone density loss caused by hormonal changes, specifically, a decline in estrogen levels, per a study published in the Journal of Clinical Medical. The research found postmenopausal women had less lean muscle in their legs and less bone mineral density in their femurs. Dr. Itri says a decline in testosterone, which is just as important in women as it is in men, can also be to blame. 

During this phase of life, women also often experience a redistribution of body fat, with increased accumulation in the abdominal area, particularly visceral fat, according to a study review published in Women’s Health Report. On average, visceral fat increases from 5-8% of total body fat in the premenopausal state to 15-20% in the postmenopausal state.

As for men, they face similar age-related loss of muscle mass and bone density from the decline in testosterone. Research published in Frontiers in Endocrinology states the decline of testosterone typically begins around the age of 40 and can continue to slide between 1-3% per year.

The good news is that it’s totally possible to slow some of these negative effects, and doing so starts with looking under the hood. "For men and women, tracking body composition is very important," says Dr. Itri. Additionally, both men and women of all ages should engage in regular strength training, he says, to help prevent the loss of muscle and bone mass. He also suggests talking to your healthcare provider about hormone replacement therapy (HRT) which many find incredibly helpful. 

3. You’re experiencing chronic pain or recurrent pain

Chronic pain affects approximately 20% or 51.6 million adults in the U.S. alone, according to the International Association on the Study of Pain (IASP). And that pain has been shown to be associated with inflammation, poor sleep, cognitive issues, relationship strain, mood disturbances, and more. These effects can then create a cycle of worsening pain and quality of life decline. But, did you know that chronic pain may be caused by muscular asymmetries or imbalances? 

“In many instances, asymmetries or imbalances can tell you why you have a certain kind of pain or underlying injury and it can direct treatment,” says Dr. Itri. “If you send a [body composition] report to a physical therapist and they see an imbalance,   that will give them insights on how to tailor or personalize treatment,” he adds.

Muscle imbalances, where certain muscle groups are disproportionately stronger or weaker than others, can lead to poor posture, altered movement patterns, and ultimately, chronic pain, Dr. Itri explains.  But it’s a two-way street: poor posture can also cause muscular imbalances. For example, weak core muscles paired with overactive lower back muscles can shift excessive strain onto the lumbar spine leading to lower back pain.    

Research has also shown that body composition can influence pain sensitivity. A study published in Pain found that individuals with higher body fat percentages had lower pain thresholds, suggesting a link between increased fat and pain perception.

A Prenuvo whole body MRI with a body composition report provides you with something called a Volume Asymmetry Index (VAI) which provides insights into how balanced or imbalanced all of the muscles in your lower body and hips are. These findings can potentially help to identify the underlying causes of chronic pain and inform targeted interventions.

4. You’re concerned about your alcohol consumption

Even if you’re a casual drinker, alcohol has been shown to have significant effects on body composition and organ health, particularly the liver. And with the U.S. Surgeon General Dr. Vivek Murthy’s new advisory around alcohol consumption, tracking body composition and organ health is more important than ever. 

Recent data from the NIH shows that alcohol was involved in 44.5% of the 96,610 liver disease deaths in 2023. Additionally, a significant portion of liver cirrhosis deaths among people of all ages were alcohol-related. The reason for this? It’s the liver’s job to clear the alcohol.

"Alcohol is metabolized by the liver and its metabolites are poison, and that damages the liver," explains Dr. Itri. "It [the liver] has got incredible capacity to regenerate, but you’ve got to keep an eye on it and your hepatic fat because the earlier you can get into an intervention if you need it, the more you can preserve it and the more likely you have better health," he adds.

Does this mean you should abstain from alcohol forever? Not necessarily, but be proactive. The liver fat analysis in a body composition report allows you to keep an eye on the health of the organ, along with your kidneys and spleen, too. 

5. You’re looking to have a baby

Fertility isn’t about timing and luck — it’s a bit of a biological equation where your body composition plays a role. And research has continuously shown connections between body fat distribution and reproductive health.

"Body fat percentage is crucial for women's fertility because it affects hormone production and regulation," explains Dr. Itri. In fact, a 2023 study published in Nature found an association between higher levels of visceral fat with a higher incidence of infertility in U.S. women. However, not enough body fat can be problematic, too. "Too little body fat can disrupt estrogen levels, while excess fat can lead to insulin resistance and hormonal imbalances," he explains.

As for men, body composition is just as important. A 2023 study review published in Fertility and Sterility suggests that obesity and metabolic disorders impact fertility in men. That said, Dr. Itri suggests men do everything they can, like diet and exercise, to maintain a healthy body composition to support optimal testosterone levels and sperm production.

He also adds that fertility is said to be 50% the man and 50% the woman, so keeping an eye on body composition while trying to conceive is a good idea for everyone involved.

Start tracking your body composition

No matter where you are in life, tracking your body composition is a valuable tool for being proactive about your health. To learn more about the benefits of a Prenuvo Whole Body Scan with Body Composition Analysis, book a call with a member of our care team.

FAQ

What is body composition, and why does it matter for health?

Body composition measures how much muscle, fat (including visceral fat), bone, and organ tissue you have—not just your weight. These metrics are powerful indicators of metabolic health, injury risk, and long-term disease risk.

What information does a Prenuvo Body Composition Analysis Report provide?

It shows how muscle, fat, and key organs are distributed throughout your body, including hard-to-see areas like visceral and liver fat. These insights help reveal risks and changes that aren’t visible from the outside. You can learn more about the Prenuvo Body Composition Analysis Report here.

Why is body composition important if I’m taking a GLP-1 weight loss medication?

GLP-1 medications can cause muscle and bone loss alongside fat loss. Tracking body composition helps ensure weight loss is coming from fat while preserving muscle and supporting metabolic health.

Can body composition explain chronic pain or recurring injuries?

Possibly. Muscle imbalances and asymmetries can contribute to poor movement patterns and chronic pain. Prenuvo can help identify these imbalances and guide more targeted physical therapy or training.

How often should body composition be tracked?

For most people, tracking every 6–12 months is helpful to monitor changes over time. If you’re undergoing rapid weight loss, hormonal changes, or treatment, more frequent check-ins such as every 3 months may be appropriate.

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