Trends, Determinants, and Health Consequences of Overweight and Obesity in Indonesia: A Longitudinal Study ^†

Obesity has become a concern in low- and middle-income countries, such as Indonesia, in recent years. This is an important issue for the country because the detrimental health impacts of obesity on non-communicable diseases are well established. The aims of this research are to understand the epidemiology of overweight and obesity and to model the trajectories of body mass index (BMI) in the Indonesian population. Data come from the Indonesian Family Life Survey, a large population-based longitudinal study over a 21-year period (1993–2014). The survey included 42,537 adults (20,778 males; 21,759 females) aged 19 to 75+ years and 105,820 total observations (49,684 males; 56,136 females). We examined changes in BMI across time, by gender, age, and birth cohort. A Group Based Trajectory Model (GBTM) was used to estimate the shape and number of BMI trajectory groups. A GBTM uses a finite mixture model to identify groups of individuals following similar developmental trajectories of BMI over time. Probability distributions based on maximum likelihood estimation were used to determine group membership. The mean BMI in adults increased between 1993 and 2014 (21.4 kg/m² in 1993 to 23.5 kg/m² in 2014), with females having a higher mean BMI than males. Mean BMI increased with time more rapidly for those born in recent decades (people born in the 1930s had average BMIs of 20.7 kg/m² in 1993 and 20.5 kg/m² in 2014, while people born in the 1970s had average BMIs of 20.8 kg/m² in 1993 and 24.4 kg/m² in 2014). Three distinct BMI trajectories were identified: group 1 (56.7%—maintained a healthy weight throughout adulthood), group 2 (34.7%—BMI increased from a healthy weight to obese), group 3 (8.6%—consistently obese over the adult years). The shape of these trajectories differed by gender (p < 0.001) and birth cohort (p < 0.001). These findings support the urgent need for overweight and obesity prevention and intervention programs in Indonesia.