When optimizing health, precision in the data you collect is crucial. A DEXA scan (Dual-Energy X-ray Absorptiometry) is one of the most advanced tools available for assessing body composition and bone health. It's quick, non-invasive, and offers insights far beyond what scales or body fat calculators can provide.

While a DEXA scan measures various aspects of your body, the three most critical metrics it delivers are visceral fat, muscle mass, and bone density. These metrics aren't just numbers—they reflect your metabolic health, physical resilience, and long-term risk for chronic disease. By focusing on these key areas, a DEXA scan provides the actionable data needed to tailor health strategies effectively.

Visceral adipose tissue (VAT) is among the most dangerous forms of fat due to its metabolic activity and location. Stored deep within the abdominal cavity, VAT wraps around critical organs such as the liver, pancreas, and intestines. Unlike subcutaneous fat, VAT releases pro-inflammatory molecules like cytokines and adipokines, which disrupt insulin signaling, increase systemic inflammation, and contribute to conditions such as type 2 diabetes, cardiovascular disease, and non-alcoholic fatty liver disease.

VAT often doesn't correlate with outward appearance. Lean individuals may carry significant VAT, while some with higher BMI may have relatively low levels. This variability is driven by genetics and how the body partitions excess energy. When subcutaneous fat storage capacity is exceeded, excess energy is deposited as VAT, compounding health risks.

The ideal VAT level is below the 10th percentile for your age and sex, though any reduction improves metabolic outcomes. While there's no direct way to specifically target VAT, interventions that reduce overall fat—such as caloric restriction, resistance training, and high-intensity interval training (HIIT)—are effective. Regular DEXA scans provide the precision needed to track progress and refine strategies.

Skeletal muscle is not just for movement—it's a critical metabolic organ that enhances insulin sensitivity, regulates blood sugar, and maintains energy balance. The Appendicular Lean Mass Index (ALMI) measures the lean mass in your arms and legs relative to height, focusing exclusively on skeletal muscle, the tissue most relevant to strength and mobility.

Muscle mass peaks in your 20s and starts to decline in your 30s, with the rate of loss accelerating after 40. Without intervention, this decline leads to sarcopenia (muscle loss), frailty, and an increased risk of falls, fractures, and metabolic dysfunction. ALMI allows us to quantify muscle health and intervene early to preserve it.

Your goal should be to maintain your ALMI in the top 25% for your age and sex. Falling below the 50th percentile signals a need for targeted action. Strategies to build and maintain muscle include regular resistance training, adequate protein intake (0.7-1 g/lb body weight per day), and consistent physical activity. These interventions don't just preserve strength; they enhance metabolic health, mobility, and independence.

Your bones are more than structural—they play a dynamic role in metabolism, acting as reservoirs for calcium and phosphate. Bone mineral density (BMD), measured during a DEXA scan, provides two key metrics:

Bone loss begins earlier than most realize, typically in your 30s, and accelerates with age. Postmenopausal women and men over 50 are particularly vulnerable. Declining bone density increases the risk of fractures, which can cascade into reduced mobility, prolonged recovery, and further health decline.

Maintaining T- and Z-Scores above 0 is optimal for bone health, while scores below -2 indicate a need for further assessment and possible pharmacologic intervention. Preventing bone loss involves weight-bearing exercise, adequate calcium intake, and maintaining vitamin D levels in the optimal range of 40–80 ng/mL. Lifestyle factors like avoiding smoking and excessive alcohol also play a role.

The DEXA scan utilizes advanced imaging technology to distinguish between different tissues in your body with remarkable precision. The scanner consists of two primary components:

During the scan, as the X-ray beams pass through your body, each tissue absorbs them at a unique rate:

The scan takes approximately 10–20 minutes. Remaining still during the process is crucial for obtaining accurate results.

One of the most reassuring aspects of a DEXA scan is its safety, particularly in terms of radiation exposure. DEXA scans use minimal radiation, making them suitable for routine use, even for repeated measurements over time.

For most individuals, a DEXA scan once a year is sufficient to track body composition and bone density changes. If you are focused on optimizing specific metrics or undergoing targeted interventions, you might consider a scan twice a year for more detailed monitoring.

DEXA scans are valuable at any age. In your 20s and 30s, they establish baselines for fat distribution, muscle mass, and bone density, providing a foundation for proactive health management. This is the time to maximize bone strength, build muscle, and maintain healthy fat levels.

In your 40s, 50s, and beyond, DEXA scans become essential for tracking changes. Visceral fat accumulation, muscle loss, and declining bone density often accelerate during these years, increasing risks for chronic disease and reduced physical function. Regular scans enable targeted interventions to mitigate these changes and maintain long-term health.

DEXA scans are not typically covered by insurance but remain affordable, usually costing $50–$150. At Instalab, we help you locate trusted facilities and interpret your results, ensuring you gain actionable insights from this powerful diagnostic tool.

Interpreting DEXA results is straightforward when focusing on these key metrics:

For actionable insights on how to improve these metrics, pair your results with Instalab's DEXA recommendation tool, which provides tailored guidance on nutrition, exercise, and supplementation based on your unique body composition.