Accuracy of the Lunar Prodigy dual energy X‐ray absorptiometer to measure body composition

PURPOSE: This investigation aimed to determine the accuracy of the Lunar Prodigy dual energy X‐ray absorptiometer (DXA) to measure body composition. METHODS: A total of 55 healthy men and women [mean ± SD; age, 27.35 ± 6.89 y; body weight, 71.96 ± 14.32 kg; % body fat, 21.24 ± 0.08 (range 6.86 to 38.10%)] performed three separate scans: a baseline scan (no lard), followed in random order by a scan with 2 kg of lard placed on the upper thigh region, and a scan with 2 kg of lard placed on the lower abdominal area. Subjects remained lying in the supine position for each scan without readjustment. Scans were analyzed using enCORE version 6.00.270 software. RESULTS: With 2 kg of lard placed on the abdomen, the total mass measured from the whole body scan was strikingly accurate (1.99 ± 0.83 kg); however fat mass was overestimated (2.64 ± 1.22 kg). Similarly, total mass measured was highly accurate when 2 kg of lard was placed on the thigh (2.00 ± 0.42 kg); but fat mass was overestimated (2.49 ± 0.56 kg). The relation between measured and predicted total mass was highly correlated with lard in the abdomen (r = 0.998) and thigh (r = 1.000) regions. Likewise, the relation between measured and predicted fat mass was highly correlated with lard in the abdomen (r = 0.982) and thigh (r = 0.996) regions. CONCLUSION: The Lunar Prodigy DXA was remarkably accurate at detecting the extra 2 kg placed in either the abdomen or thigh region, but tended to slightly overestimate fat mass while underestimating lean body mass.