Body Fat Distribution in Lean Individuals with Metabolic Abnormalities

Objective: Obesity, defined as body mass index (BMI) >30 kilogram/m2 is associated with metabolic derangements, but lean individuals with BMI <25 kilogram/m2 may also have metabolic abnormalities. This study was conducted to evaluate fat distribution in metabolically unhealthy lean (MUL) individuals. Methods: Adults with BMI 18.5-24.9 kilogram/m2 had their body composition evaluated with dual-energy X-ray absorptiometry. Metabolic data were obtained from their medical records. Patients with ≥2 components of the metabolic syndrome (MetS) were considered MUL and those with ≤1 component metabolically healthy lean (MHL). Multivariable logistic regression was used to analyze the association between metabolic abnormalities and anthropometric indexes. Results: The study includes 119 subjects; 69 in MHL and 50 in the MUL group. Two groups had comparable total body fat, fat mass index, and appendicular lean mass. Indices of visceral fat were associated with increased odds of being MUL (odds ratio with 95% confidence interval): visceral adipose tissue 1.75 (1.13-2.73), trunk-to-legs fat ratio 2.28 (1.30-4.00), trunk-to-limb fat ratio 2.43 (1.37-4.32), android-to-gynoid fat ratio 1.80 (1.07-3.03), and visceral-to-total fat percentage 1.80 (1.07-3.05). Conclusion: Metabolically unhealthy subjects had increased truncal distribution of body fat without an increase in total body fat. Body morphometry in MUL was similar to that of obese individuals with MetS.