Assessing obesity beyond body mass index: Integrating physiological and functional indicators of impairment in national health surveillance.

Just over one in four Canadian adults had excess adiposity as defined by measured BMI in the obese range plus elevated waist circumference.

• Data were drawn from the 2016 to 2019 Canadian Health Measures Survey
• Excess adiposity was defined as measured BMI in the obese range combined with elevated waist circumference
• Both measured and self-reported data were used

Clinical and preclinical obesity prevalences differed substantially depending on the tier threshold used.

• At Tier 1 (impairment in one or more domains): clinical obesity prevalence was 19% and preclinical obesity prevalence was 8%
• At Tier 2 (impairment in two or more domains): clinical obesity prevalence was 12% and preclinical obesity prevalence was 15%
• At Tier 3 (impairment in three or more domains): clinical obesity prevalence was 7% and preclinical obesity prevalence was 20%
• A three-tier system was used to capture progressive obesity-related impairment across eight body system domains

Preclinical obesity was more common in younger adults and females, particularly at Tiers 1 and 2.

• Younger adults and females with excess adiposity were less likely to present with obesity-related physiological dysfunction or activity limitation
• This pattern was described as indicating early stage impairment
• The finding was noted to highlight opportunities for targeted prevention in these groups

Prevalence of physiological dysfunction and activity limitation indicators varied across the eight body system domains as well as by sex and age group.

• Eight body system domains were used to assess indicators of physiological dysfunction and activity limitation
• Variation was observed across domains, sex, and age groups
• Prevalence estimates were calculated separately by sex and age group

The study applied the 2025 Lancet Diabetes and Endocrinology Commission recommendations to national health surveillance data by combining excess adiposity with indicators of physiological dysfunction and activity limitation.

• The approach combined population-level measures of excess adiposity with indicators across eight body system domains
• Clinical obesity was defined by excess adiposity and indicators of impairment meeting tier-specific thresholds
• Preclinical obesity was characterized by excess adiposity with fewer indicators of impairment than the corresponding clinical thresholds
• The authors concluded that integrating measures of impairment when assessing obesity can refine population surveillance efforts