Does youth adiposity, or change in adiposity from youth to adulthood, predict metabolically healthy obesity in adulthood?

Background: Individuals with metabolically healthy obesity (MHO) do not have the metabolic complications usually associated with obesity.

Objective: To examine whether youth adiposity, or change in adiposity from youth to adulthood, predicts MHO 20 years later.

Methods: A national sample of 2410 Australian participants had height, weight and waist circumference (WC) measured in 1985 (7–15 years old) and 2004–2006 (26–36 years old). A fasting blood sample was taken in 2004–2006. MHO was defined as body mass index (BMI) ≥ 30 kg m⁻², normal fasting glucose (< 5.6 mmol L⁻¹), triglycerides (< 1.695 mmol L⁻¹), high-density lipoprotein-cholesterol (> 1.036 mmol L⁻¹ men, > 1.295 mmol L⁻¹ women), blood pressure (< 130/85 mmHg) and no medication for these conditions. Relative risks (RR) were calculated using log binomial regression and expressed per unit of youth BMI (or WC) z-score or change in BMI (or WC) z-score from youth to adulthood, adjusted for sex and youth age.

Results: In total 323 individuals were obese at follow-up, 79 (24.5%) were MHO. Adult MHO was not associated with youth BMI (RR: 1.00, 95%CI: 0.85-1.19) or WC (RR: 0.93, 95%CI: 0.79-1.11). Individuals were less likely to be MHO if they had larger increases in BMI (BMI RR: 0.74, 95%CI: 0.57-0.97) or WC (RR: 0.70, 95%CI: 0.55-0.90) from youth to adulthood.

Conclusions: Change in adiposity from youth to adulthood predicted adult MHO better than youth adiposity alone.