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DEXA SCAN
LONDON
Body Composition & Bone Density Analysis
What Is a DEXA Scan?
A DEXA scan (Dual-Energy X-ray Absorptiometry, also written as DXA) is a medical-grade diagnostic imaging test that provides precise measurement of body composition, bone mineral density, and fat distribution. Unlike scales, BMI calculations, or consumer body composition devices, DEXA scanning uses ultra-low-dose X-ray technology to accurately distinguish between lean muscle mass, fat mass, visceral fat, and bone density.
At Reborne Longevity in London, DEXA body composition scanning is a foundational diagnostic for precision longevity medicine. The data from DEXA scans enables our clinicians to design truly personalised programmes for metabolic health, performance optimisation, hormonal balance, and long-term disease prevention.
What Does a DEXA Scan Measure?
Lean Muscle Mass: Total and segmental (arms, legs, trunk) muscle distribution, left-right asymmetry, and detection of age-related muscle loss (sarcopenia). Essential for athletes, ageing adults, and anyone monitoring fitness progress.
Body Fat Percentage and Distribution: Total body fat with regional breakdown. Critically distinguishes between subcutaneous fat (under the skin) and visceral fat (around organs) - a key metabolic health marker.
Visceral Adipose Tissue (VAT): Precise quantification of visceral fat, which is strongly associated with metabolic syndrome, type 2 diabetes, cardiovascular disease, and inflammatory conditions. This cannot be accurately measured by other methods.
Bone Mineral Density (BMD): The gold standard measurement for detecting osteopenia, diagnosing osteoporosis, and assessing fracture risk. Reports T-scores comparing your bone density to healthy young adults.
Body Symmetry: Left-to-right comparison of muscle mass distribution, critical for identifying imbalances that increase injury risk and affect athletic performance.
How Does a DEXA Scan Work?
DEXA technology works by passing two low-energy X-ray beams through the body. Different tissues (bone, muscle, fat) absorb these beams at different rates, allowing the scanner to calculate precise measurements of each tissue type. The dual-energy approach enables separation of bone mineral content from soft tissue, and further differentiation between lean mass and fat mass.
The radiation exposure from a DEXA scan is extremely low - approximately 1-10 microsieverts, equivalent to a few hours of natural background radiation or less than a transatlantic flight. This makes DEXA safe for regular monitoring.
What Happens During a DEXA Scan?
A DEXA scan at Reborne Longevity is simple, fast, and completely non-invasive. You lie comfortably on the scan table wearing loose clothing (no metal fastenings). The scanning arm passes over your body, taking measurements. The entire process takes just 5-10 minutes.
No injections, no fasting, no special preparation, and no recovery time. You can return immediately to normal activities. Results are interpreted by the Reborne clinical team and integrated directly into your personalised longevity programme.
Why Is DEXA Better Than Other Body Composition Methods?
Most body composition methods provide estimates rather than measurements. Scales measure weight but cannot distinguish muscle from fat. BMI is a simple ratio that ignores body composition entirely. Bioelectrical impedance (used in smart scales and handheld devices) is affected by hydration, recent exercise, and food intake, with significant day-to-day variability.
DEXA provides objective measurement with high precision and reproducibility. It is the reference standard used in clinical research for body composition assessment. For tracking changes over time - whether fat loss, muscle gain, or bone density changes - DEXA offers the accuracy needed to detect real progress versus normal fluctuation.
Who Should Get a DEXA Scan?
Weight Management and Metabolic Health: DEXA quantifies visceral fat (the metabolically dangerous fat around organs.
Athletes and Performance Optimisation: DEXA provides precise body composition data for training periodisation.
Menopause and Hormonal Transitions: DEXA establishes baseline measurements before hormonal changes accelerate.
Bone Health and Osteoporosis Risk: DEXA is the gold standard for early osteopenia detection and osteoporosis diagnosis.
Ageing and Longevity Medicine: DEXA tracks age-related muscle loss (sarcopenia), monitors body composition changes that predict healthspan.
Frequently Asked Questions About DEXA Scans
How accurate is a DEXA scan for body fat?
DEXA is considered the clinical gold standard for body composition measurement, with precision of approximately 1-2% for body fat percentage. It is the reference method used in research studies against which other technologies are validated. While no method is perfect, DEXA offers the best combination of accuracy, reproducibility, and practical accessibility.
Is DEXA scan radiation safe?
Yes. DEXA uses ultra-low radiation - approximately 1-10 microsieverts per scan, which is less than the radiation from a transatlantic flight or a few hours of natural background exposure. This extremely low dose makes DEXA safe for regular monitoring. For comparison, a chest X-ray delivers approximately 100 microsieverts.
How often should I get a DEXA scan?
For body composition monitoring, DEXA scans are typically repeated every 3-6 months to track changes in response to interventions. For bone density assessment, annual or biennial scans are common depending on risk factors. Your clinician will recommend an appropriate monitoring schedule based on your individual goals and health profile.
What is visceral fat and why does it matter?
Visceral fat is fat stored deep in the abdominal cavity, surrounding internal organs including the liver, pancreas, and intestines. Unlike subcutaneous fat (under the skin), visceral fat is metabolically active and releases inflammatory compounds. High visceral fat is strongly associated with insulin resistance, type 2 diabetes, cardiovascular disease, and certain cancers. DEXA accurately quantifies visceral fat, which cannot be reliably measured by other methods including waist circumference.
Can DEXA detect muscle imbalances?
Yes. DEXA provides segmental body composition data, comparing lean mass in left versus right arms and legs. This identifies asymmetries that may indicate injury risk, rehabilitation needs, or training imbalances. Athletes use this data to optimise performance and prevent injury.
What is a T-score on a DEXA scan?
The T-score compares your bone mineral density to that of a healthy 30-year-old adult of the same sex. A T-score of -1.0 or above is normal. Between -1.0 and -2.5 indicates osteopenia (lower than normal bone density). Below -2.5 indicates osteoporosis. T-scores help assess fracture risk and guide treatment decisions.
How does DEXA compare to InBody or bioelectrical impedance?
Bioelectrical impedance devices (including InBody, smart scales, and handheld analysers) estimate body composition by measuring electrical resistance through the body. Results are significantly affected by hydration status, recent food and drink, exercise, and time of day. DEXA measures tissue directly using X-ray absorption, providing more accurate and reproducible results. DEXA also provides regional data and visceral fat measurement that BIA cannot.
Do I need to prepare for a DEXA scan?
No special preparation is required. Wear comfortable clothing without metal (zippers, underwire). Avoid calcium supplements on the day of your scan as they may affect bone density readings. For most accurate body composition tracking over time, try to scan under similar conditions (same time of day, similar hydration status).
Where can I get a DEXA scan in London?
Reborne Longevity offers medical-grade DEXA body composition and bone density scanning in central London (Queen Anne Street, W1). Results are interpreted by our clinical team and integrated into personalised longevity programmes.
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