Children in a low-income urban community in Vellore are experiencing both persistent thinness and rising obesity by primary school age, according to a study released on July 2. The longitudinal birth cohort study followed 251 children and found that while thinness remained common, the prevalence of overweight and obesity nearly tripled between ages seven and nine, highlighting what researchers describe as the "double burden of malnutrition."
The research was conducted through a collaboration between the Advanced Research Unit on Metabolism, Development and Aging at the Tata Institute of Fundamental Research and Christian Medical College (CMC), Vellore. Dr. Beena Koshy from CMC Vellore led the study along with Dr. Birsen Yilmaz from ARUMDA, TIFR. Of the original 251 children enrolled at birth, 205 were followed up to nine years old with height and weight measured at several points.
Most children maintained a normal body mass index during their first five years; however, by age seven, 26.3% were classified as thin while 5.2% were overweight or obese. By age nine, thinness persisted at 21.6%, but overweight and obesity rose to 14.6%. Dr. Beena Koshy said, "Our findings show that children in low-income urban communities are now facing both thinness and emerging obesity before they even enter their teens, which means malnutrition in India is no longer just about underweight toddlers, but about the entire childhood years."
The study also found strong links between low maternal BMI or child’s low birth weight with later childhood thinness; meanwhile, those born with normal birth weight had higher likelihoods of developing obesity by age nine—suggesting an influence from changing diets and physical activity patterns as environments urbanize rapidly.
Dr. Nihal Thomas of CMC Vellore said, "Undernutrition in early life can lead to two potential trajectories...Persistence of undernutrition...can potentially lead to defects in insulin secretion...On the contrary...overweight...could lead to an exponential increase in overweight and subsequently increase risk of diabetes, hypertension and cardiovascular disease." The findings highlight primary school years—especially ages seven to nine—as critical for rising rates of overweight even as undernutrition remains prevalent.
Professors Ullas Kolthur (ARUMDA) and Mahendra Sonawane (TIFR) said, "Our findings suggest the importance of focusing on child growth beyond the first 1,000 days...Extending nutrition...into primary school years is essential because this is when children's metabolic profiles are being shaped." Dr. Nihal Thomas added that addressing India's double burden would require balanced public health strategies: "The public health policies that need to evolve...would need a judicious blend of lifestyle interventions ...promoting higher-protein diets through potentially cost-effective formulations."
