At what age do normal weight Canadian children become overweight adults? Differences according to sex and metric

Abstract

Background: The prevalence of overweight and obesity doubles between adolescence and young adulthood; however, the exact age, and appropriate metric to use to identify when overweight develops is still debated. Aim: To examine the age of onset of overweight by sex and four metrics: body mass index (BMI), fat mass (%FM), waist circumference (WC) and waist-to-height ratio (WHtR). Subjects and methods: Between 1991 and 2017, serial measures of body composition were taken on 237 (108 males) individuals (aged 8–40 years of age). Hierarchical random effects models were used to develop growth curves. Curves were compared to BMI, %FM and WC overweight age- and sex-specific cut-points. Results: In males, the BMI growth curve crossed the cut-point at 22.0 years, compared to 23.5 and 26.5 years for WHtR and %FM, respectively; WC cut-off was not reached until 36 years. In females, the BMI growth curve crossed the overweight cut-point at 21.5 years, compared to 14.2 years for %FM and 21.9 and 27.5 years for WC and WHtR, respectively. Conclusion: In summary, overweight onset occurs during young adulthood with the exception of WC in males. BMI in males and %FM in females were the metrics identifying overweight the earliest.

Keywords

• longitudinal
• body mass index
• growth
• overweight
• waist circumference