No matter what kind of relationship you have with your scale, it’s not telling you the whole truth.
As a 52-year-old former fashion executive turned health optimization coach, I learned this lesson firsthand through my own health journey through perimenopause. It wasn’t until I got a DEXA scan and took a look under the surface that I truly unlocked the insights into my changing metabolism and body composition.
“For too long, we’ve pursued being thin, and used it as a proxy for being healthy.”
We live in a culture obsessed with body size. For too long, we’ve pursued being thin, and used it as a proxy for being healthy. Women in particular are taught to eat less, do more cardio, and limit their weightlifting to under ten pounds. This is doing us more than a disservice — it has caused generations of women to suffer in their later years with osteoporosis, dementia, and heart disease.
Unfortunately, the data suggests that in our modern world, we are becoming unhealthy at any size. One study estimated that 88% of American adults have poor metabolic health. Looks can most definitely be deceiving.
But, we are now waking up. More women are starting to question the numbers we’ve been told to chase. I know because I did exactly that.
An eye-opening revelation
For most of my adult life, I’ve worn the same size 26 jeans and assumed that my normal weight wasn’t a point of concern. That is, until I read Dr. Peter Attia’s book, “Outlive.” In it, he declared that every patient in his longevity practice must get an annual DEXA scan to measure fat, muscle, and bone mass.
Until then, I’d only heard of DEXA scans in relation to professional athletes or as a test that older women received after 65 to check for osteoporosis. But it made perfect sense to me. In a world of advanced technology, why wouldn’t we use a machine that could tell us what our bodies were actually made of? A traditional scale, by comparison, felt like a blunt instrument that could only deliver a vanity number with no real context.
“In a world of advanced technology, why wouldn’t we use a machine that could tell us what our bodies were actually made of?”
I walked into my first DEXA scan with the self-assurance of a fit, 49-year-old health professional who was checking all of the boxes — lifting weights, eating protein, and taking creatine. So I was surprised to learn that my results told a very different story. Turns out my body composition wasn’t nearly as optimal as I thought.
According to the clinic’s wellness coach, whom I consulted to make sense of my disappointing results, I was “tracking with the average of women my age.” This meant a cohort of women aged 49-55 who were heading into menopause, if not there already. As a health optimizer (and self-proclaimed overachiever), all I heard was the word average.
My DEXA scan showed a higher-than-desired total body fat percentage. But, here’s the eye-opening part: It wasn’t because I was overweight or “over-fat.” It was because I didn’t have enough muscle.
Why muscle matters more than you think
As we get older, we naturally begin to lose muscle mass, and the balance between lean tissue and fat starts to tip in the wrong direction. This change can happen quietly, even in people who appear to be slim or are within a “normal” or even low weight range.
It’s a phenomenon called “skinny fat,” a body composition in which too little of your weight comes from muscle. The clinical term is sarcopenic obesity (too much visceral fat and not enough lean muscle mass), which increases the risk for:
- Osteoporosis (brittle, weak bones)
- Heart disease
- Frailty
- Metabolic syndrome
- Insulin resistance
Even as an educated wellness expert, it seemed that my diet and lifestyle interventions were falling short of my goals. The scale had given me false reassurance while this body composition scan revealed the rest of the story — that my metabolism was taking a hit and I needed to course correct.
“The scale had given me false reassurance while this body composition scan revealed the rest of the story.”
Armed with this valuable knowledge, I started to coach other midlife women who were heavily invested in their health but frustratingly not seeing tangible results. My advice to them? Shift your focus from an aesthetics-only approach and understand the levers to pull to support an efficient metabolic system. Only then will you achieve both goals: look better naked today while maintaining resilience for the future.
What is body composition, anyway?
The shift in narrative from weight loss to body recomposition is one of the most critical reframes in longevity medicine. When we stop attributing value to that opaque number on the scale and focus on our body composition, we start looking through the lens of healthspan, instead of vanity.
Body composition refers to the percentages of fat, muscle, and bone that make up your total body weight. In a clinical setting, physicians, trainers, and health coaches look at these key metrics:
- Bone mass: The density and weight of your skeleton
- Lean mass: Primarily muscle but includes organs and water
- Fat mass: Subcutaneous fat (under the skin) and visceral fat (around the organs)
“The shift in narrative from weight loss to body recomposition is one of the most critical reframes in longevity medicine.”
This is why weight is not a proxy for health, because once you dig deeper, you find vastly different body compositions that each tell a different story. Getting a baseline for these components helps to track the changes over time. Age, genetics, ethnicity, and lifestyle are all contributing factors. If you are relying on your BMI, a mirror reflection, or your jean size, you could be missing the red flags that will sabotage your healthspan.
A heavier person could have more muscle mass and denser bones, which contribute to better metabolic health, balance, and strength — allowing for more function later in life. A thinner person could have less ability to store fat, resulting in more inflammatory visceral fat, which leads to increased risk of diabetes and cardiovascular disease. Declining muscle mass in already lean individuals can mean weaker bones and a higher risk of frailty.
“Loss of muscle leads to rises in cortisol, insulin, stress hormones, and blood sugar levels,” says Dr Gabrielle Lyon, an expert in Muscle-Centric Medicine. “These issues can occur quietly, without significant gains in weight, which is why it’s vital to measure these markers of your internal health.”
So, what exactly is a DEXA scan?
A DEXA (dual-energy X-ray absorptiometry) scan is a diagnostic scan that shows what your total body weight is comprised of — fat, muscle, and bone. It reveals how much of each you have, where that mass is distributed, and how it shifts as time passes.
“A DEXA (dual-energy X-ray absorptiometry) scan is a diagnostic scan that shows what your total body weight is comprised of — fat, muscle, and bone.”
The scan itself is quick and painless — you stay fully clothed and lie on a table while a mechanical arm glides over your body for about seven minutes. Your results are typically emailed to you within the hour, complete with a detailed breakdown.
Here’s what you’ll learn from your scan:
Lean Tissue
- This is basically everything that is not fat or bone mass.
- It’s mostly muscle but also includes organs, connective tissue, and fluids.
Appendicular Lean Mass (ALM)
- Measures how much muscle you have on your arms and legs — your “functional muscles” that allow you to do every day activities.
Bone Mineral Density (BMD)
- The mineral density in your skeleton such as the spine, hips, and wrists.
Resting Metabolic Rate
- The calories your body burns at rest to maintain essential functions like breathing.
Total Body Fat Percentage
- This includes both subcutaneous fat (under the skin) and visceral fat (around the organs).
Visceral Adipose Tissue (VAT)
- The fat you cannot pinch that is found in your abdominal cavity. It’s inflammatory and increases risk of chronic disease.
For the price, under $125 in most major cities, DEXA scans are one of the most impactful health optimization tools we have. It doesn’t need a prescription from a doctor and, thankfully, is becoming more available at gyms and wellness clinics all over the country.
Is it safe? Yes, the radiation from this scan is minimal — about the same as a cross-country flight and far less than a mammogram.
Unfortunately, it’s not usually covered by insurance until age 65, which, by now, you realize is way too late to learn about your increasing visceral fat or declining bone density. According to OBGYN Dr Mary Claire Haver, here are some risk factors that might qualify for an early screening:
- A previous fracture in the hip, vertebrae, shoulder, pelvis, or wrist
- A family history of osteoporosis
- Early menopause
- A petite body frame (weighing 125 and under)
- A history of smoking and/or heavy drinking (2 or more drinks per day)
- Medications like corticosteroids
- Liver disease or rheumatoid arthritis
The good news is that most scans can be paid for with your FSA or HSA plan as a legitimate health expense.
What happens as we age?
I’ve reached that age when I’ve started to say, “I wish I knew this in my 30s.” Why 30s? Because according to Dr Lyon, most of us reach our peak in bone density and muscle mass between the ages of 25 and 30. It’s a slow decline from there, unless we intervene through targeted diet and exercise.
Our third decade becomes the ideal moment for people, especially women, to start paying attention to the changes that come with aging, which are accelerated by the rapid hormonal decline in menopause.
Starting at the age of 30, muscle mass decreases by approximately 3-8% per decade, and this rate accelerates around age 60. Even if we do everything right, we will experience an involuntary loss of muscle mass, strength, and power — a process known as sarcopenia. It’s a major reason why older adults become more prone to falls and injuries.
“Starting at the age of 30, muscle mass decreases by approximately 3-8% per decade, and this rate accelerates around age 60.”
We experience a shift in fat distribution because of declining estrogen, which starts to pool around the middle. It’s not just about how our clothes fit. The body composition changes around our abdomen may indicate an increase in dangerous visceral fat that raises our risk for insulin resistance, type 2 diabetes, and heart disease.
As muscle decreases, bone density follows. It’s estimated that for women, we can lose up to 20% of our bone density in the 5-7 years following menopause. According to Dr Haver, an estimated 40-50% of postmenopausal women will experience an osteoporotic fracture in their lifetime, some of which can be fatal.
But I’m here to encourage you that knowledge is power. Aging might be inevitable, but how we age is entirely dependent on the interventions we make part of our daily lives starting in our 30s. Body composition metrics inform this important lifestyle reboot, which is made up of small, sustainable changes.
Five foundational shifts from a health coach
Forget weight loss, body recomposition is the true unlock. The goal is to burn fat while preserving or preferably building lean muscle. Your total weight may stay the same or even rise, but you’ll be leaner and stronger without compromising your long-term metabolic health.
- Build strength, not only burn calories
Adding in strength training 2-3x a week will recompose your body in a healthy way. Learn to lift heavy safely through progressive overload (slowly increasing weights) on compound movements like squats and deadlifts. Excessive cardio will have the reverse effect as you age.
- Nourish your body, don’t diet
Chronic undernourishment, especially undereating protein, will backfire by lowering your resting metabolic rate (the amount of calories you burn at rest). Not only will you be underfueled and have less energy, your engine will be less efficient, causing potential fat gain. Plus, bones need protein and nutrients like magnesium and vitamins D3/K2 to stay strong.
- Rethink your relationship with alcohol
Even “moderate” drinking can disrupt sleep, impair recovery, and sabotage your goals. If your body is busy metabolizing alcohol, it’s not building muscle or oxidizing fat. It can block nutrient absorption and impact essential hormones vital for maintaining bone density.
- Manage stress, it’s a vital sign
Life is busy and unpredictable, but learning how to manage your stress is critical. It impacts your hormones, inflammation, fat storage, and sleep. This could mean journaling or breathwork or even taking a long walk with a friend, instead of turning to your phone.
- Sleep is a non-negotiable
Your mind and body repair themselves when you sleep. You’ll reduce your progress with muscle gains, fat loss, and metabolic efficiency by not prioritizing rest and recovery. Dark, cold rooms, eye masks, and supplements like magnesium glycinate and L-theanine can help.
Why DEXA belongs in your longevity toolkit
You cannot optimize what you don’t measure. DEXA scans give you the information you can actually do something with.
Longevity doctors, health optimization coaches, integrative nutritionists, and menopause experts may not agree on everything, but they are aligned on the importance of understanding your body composition. Your scan metrics empower smarter decisions around how you eat, train, supplement, and recover on your longevity journey.
“You cannot optimize what you don’t measure. DEXA scans give you the information you can actually do something with.”
Unlike some advanced diagnostics, this one’s surprisingly accessible, as low as $49 in some markets, making it a health optimization tool everyone can start using in their 30s. If you’re generally healthy and young, I recommend making it part of your annual health check-up alongside comprehensive blood work and your in-person exam with your doctor.
For those actively working on muscle gain or tracking fat loss during menopause or a medical issue, you may benefit from a scan every 8-12 weeks.
Just remember that meaningful change comes from slow, steady body recomposition. Taking action from the insights from your DEXA scan enables better decisions not just today, but for decades to come.
Celia Chen is a certified health optimization coach, brand consultant and founder of Chenessa, an advisory that offers private coaching, and corporate workshops on menopause, metabolism, and longevity. Follow her on Substack and Instagram for more wellness insights.
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