A quasi-cohort trend analysis of adult obesity in Colombia.

In Colombia, the prevalence of obesity has been increasing in recent years due to changes in dietary and nutritional patterns. While previous studies have focussed on describing obesity and its associated factors, they have mainly used a cross-sectional methodology. Accordingly, this study aims to conduct a descriptive quasi-cohort analysis to capture age-specific cohort trends in body mass index (BMI) according to sex and ethnicity (indigenous, Afro-Colombian, and the remaining population). The study utilised data from the National Survey of the Nutritional Situation in Colombia (ENSIN) conducted in 2005, 2010, and 2015 that included 214,136 individuals aged 20-64 years after screening. Data on ethnicity were only available from the 2010 and 2015 surveys. Overall, the prevalence of obesity increased by 6.1 percentage points (from 15.2% to 21.3%) between 2005 and 2015 (men from 10.4% to 15.7%; women from 18.2% to 25.7%). Among Afro-Colombians, obesity rose 6.6 percentage points (from 19.4% to 26.0%), again more so in women than in men (2015: 35.2% versus 17.8%). Among indigenous people, the proportion increased by 5.3 percentage points (from 13.5% to 18.8%), with women reporting highest rates (2015: 23.7% against 12.6% in men). Age- and cohort-specific results also indicate that recent adult cohorts are experiencing sharp increases in BMI, for example, while 25-29-year-old males born in 1975-1979 had a BMI of 24.2 kg/m, among 40-44-year-olds of the same cohort, this equalled 26.8 kg/m. In the case of women, these age differences in BMI among the same cohort are even greater (24.4 and 28.0 kg/m). In summary, the results of this study indicate that Colombia is still in the early stages of the obesity transition, urging the need to monitor obesity trends in Colombia from both an age and cohort perspective. To achieve this, longitudinal surveys or repeated cross-sectional surveys like the ENSIN could be utilised.