Published Jun 07, 2026 | 7:00 AM ⚊ Updated Jun 07, 2026 | 7:00 AM
Representative image. Credit: iStock
Synopsis: A Vellore birth cohort tracked 251 children for nine years and found that a mother’s weight at conception shapes whether her child stays thin or gains weight in mid-childhood
For nine years, researchers in Vellore watched 251 children grow. What they found upends a familiar assumption: that malnutrition in India is a problem of too little, not too much. By the time these children turned nine, one in seven had tipped into obesity, in the same slum community where nearly half were stunted as toddlers.
The study, published in The Lancet Regional Health – Southeast Asia, tracked children born in urban slum communities in Vellore, Tamil Nadu, between 2010 and 2012. It is the first longitudinal evidence of its kind from India to show precisely when the double burden of malnutrition(DBM), undernutrition and obesity coexisting in the same population, breaks open: after age five, and worsening by nine.
The cohort opened with a stark finding. Nearly 45 percent of children were stunted by age two, a measure of how early and how deeply deprivation reaches into low-income urban communities.
But through age five, most children held. A high percentage maintained a normal body mass index. The crisis, at that stage, had not yet split.
Then it does.
By age seven, 26.3 percent of children were classified as thin. Alongside them, 5.2 percent had already crossed into overweight or obesity. By age nine, thinness had eased to 21.6 percent. Overweight and obesity had nearly tripled, reaching 14.6 percent.
The researchers described what they saw plainly: “DBM emerged in mid-childhood after five years of age, became evident at approximately seven years of age, and further worsened at approximately nine years of age.”
Also Read: Cheap obesity drugs are finally here in India, but what if you plan to stop one day?
The study traces both trajectories back to one variable: the mother’s body mass index at the time of birth.
Children born to mothers with lower body weight were significantly more likely to remain thin at ages five and nine. Each unit increase in maternal BMI corresponded to a measurable drop in the odds of the child being thin in later life. The relationship held even after researchers accounted for birth weight and sex.
The researchers found that “low maternal BMI was associated with the BMI trajectory of the offspring, highlighting the intergenerational dimension of malnutrition.”
It works at birth too. Babies born to underweight mothers weighed significantly less than babies born to mothers with higher BMI. The study recorded a mean birth weight of 2.77 kg for babies born to underweight mothers, against 3.02 kg for babies born to mothers with obesity.
The hunger a mother carries travels forward.
Children who arrived underweight faced the longest road. More than 40 percent were still classified as thin by ages seven and nine.
The researchers found that children with low birth weight carried “a higher prevalence of thinness at most ages, with the proportion increasing notably by seven years and remaining high at nine years.”
At the same time, children born at normal weight followed a different arc. Their BMI declined through early childhood, then reversed around nine. Among this group, 12.2 percent had crossed into overweight or obesity by nine.
The researchers checked whether stunted height was inflating the BMI numbers, a child who stops growing tall can appear heavier than they are. It was not. Higher BMI in this group reflected what the authors called “true obesity.”
What drives the reversal toward obesity in mid-childhood points toward the food environment. The authors flagged concerns about “easy access to cheap, unhealthy food in school environments and community settings” as one of the main factors associated with the double burden in children and adolescents.
For children in low-income urban settings, the metabolic buffer that better early nutrition might have provided was not there. Processed food reached them anyway.
India’s nutrition programmes, ICDS, PM POSHAN, concentrate their effort on children under five. The six-to-nine window, where this study shows the split widening fastest, receives no comparable systematic attention.
The researchers argued for “strengthening maternal nutrition before and during pregnancy, as well as sustained growth monitoring beyond early childhood to detect emerging risks of both undernutrition and overweight.”
They called for “integrated and context-specific strategies that consider changing dietary patterns, physical activity behaviors, and the broader food environment”, placing equal weight on what children eat at school and in their neighbourhoods as on what happens in clinics.
The authors were direct about the scale of the response needed: “A multi-pronged strategy is needed to reduce the worsening DBM trend in children. These efforts should be implemented in early to mid-childhood, with a concomitant focus placed on maternal health and well-being.”
Also Read: Awareness or surrogate advertising? CDSCO flags GLP-1 obesity campaigns
The MAL-ED cohort is small, 251 children, one city, one decade. The researchers acknowledge it does not represent the full diversity of India. Dietary intake data was not recorded, which limits how far the findings can explain the obesity trajectory. Roughly one in five children enrolled at birth were lost to follow-up, mostly because families moved away.
But it offers something national surveys cannot: a continuous record of the same children across nine years, showing precisely when the double burden emerges and what precedes it.
The authors concluded that the findings “could be helpful to support the importance of strengthening maternal nutrition before and during pregnancy” and called the intergenerational link between maternal BMI and child BMI trajectory a central finding.
The data returns, ultimately, to the same point. The moment that shapes whether a child stays thin or tips toward obesity by nine is not at age seven, or five, or even at birth. It is earlier, in the nutrition, the weight, the circumstances of the woman who carries them.
Fix that, and the trajectory changes. Leave it, and the cycle holds.
