Body Mass Index-z score trajectories of Indonesian children and adolescents between 1993-2014 and associated risk factors.

Objectives: To identify trajectories of Indonesian children and adolescents BMI-z scores between 1993 and 2014, examine whether the pattern differs by sex, and assess associations with host, agent and environmental factors.

Design: Longitudinal data were from the Indonesian Family Life Survey with up to five measurements of height and weight. Group-based trajectory models investigated change in BMI-z score across time; differences by sex were investigated using random effect (mixed) models. The association between the trajectories and host, agent and environmental factors were examined using multinomial logistic regression.

Setting: Thirteen provinces in Indonesia.

Participants: Indonesian children and adolescents aged 6-18 years (n=27 394 for BMI-z trajectories; n=8805 for risk factor analyses).

Results: Mean BMI-z score increased from -0.743 standard deviation (SD) in 1993 to -0.414 SD in 2014. Four distinct trajectory groups were estimated with mean BMI-z increasing more rapidly in the most recent time periods. One group (11.7% of participants) had a mean BMI-z entirely within the moderately underweight range; two had trajectories in the normal range; and one (5.6%) had a mean BMI-z starting in the overweight range but within the obesity range by 2014. There were differences in trajectory groups by sex (p<0.001). Those born in 2000s, frequent consumption of meat, fast foods, soft drinks, and fried snacks, and living in urban areas were associated with rapid gain weight.

Conclusions: These trajectories highlight the double burden of malnutrition and suggest that the prevalence of overweight and obesity is likely to increase substantially unless public health interventions are implemented.