McMaster researchers have identified six key factors in the first three years of life that influence the trajectory of obesity in South Asian children.

The findings offer parents, primary care practitioners and policymakers new insights into addressing childhood obesity for a group of children who have a higher prevalence of abdominal fat and cardiometabolic risk factors, as well as a predisposition to diabetes.

“We know that current measures of childhood obesity such as the body mass index (BMI) don’t work well for South Asians because of the so called ‘thin-fat’ phenotype: South Asian newborns are characterized as low birth weight, but proportionally higher body fat or central obesity (a ‘thin-fat’ phenotype) relative to White Europeans, and this pattern persists in fourth generation migrated populations,” says Sandi Azab, first author of the study and an assistant professor in the department of Medicine at McMaster.

“Most studies focus on specific points in time and mostly involve White European families, highlighting the need for more research on different ethnic groups and tracking obesity over the child’s early years rather than a single point in time,” Azab says.

The study, published in JAMA Network Open on April 10, analyzed more than 900 children and identified six modifiable factors associated with adiposity (the condition of having too much fatty tissue in the body).

Maternal factors include:

• Obesity before pregnancy
• Weight gain during pregnancy
• A health-conscious diet during and around pregnancy including poultry, eggs, fruits, vegetables, seafood and refined grains (including puri, idli and dosa)

A South Asian infant or child’s exposure to these factors in the first three years of life was associated with lower trajectory of adiposity:

• Breastfeeding for 12 months or more
• Increased daily physical activity
• Reduced screen time

A direct relationship was found between the number of these factors a child accumulates and childhood adiposity, tested across three cohorts of 3,171 children in Canada and the United Kingdom, involving both South Asian and White European children.

The researchers propose that in clinical and public health settings, children are given a combined score of these factors to identify those at risk and to target interventions to help curb childhood obesity.

The study suggests that targeted interventions and policies, such as subsidized maternal nutrition programs and access to breast pumping equipment, can support healthier life trajectories.

“The protective factors identified in our  research are modifiable, such as reduced screen time, and some which are  relatively easier to promote and implement – such as increased child physical activity in the first three years of life and extended duration of breastfeeding to the first year of life,” says Sonia Anand, corresponding author of the study and a professor in the Department of Medicine at McMaster.

“We need to disseminate the knowledge generated from this research to parents, and to shift our efforts towards developing and testing interventions to optimize health trajectories, and towards shaping actionable recommendations and policies to support healthy life trajectories,” says Anand, associate vice-president, Global Health and leader of the Mary Heersink School of Global Health and Social Medicine at McMaster.

The research was supported by the Canadian Institutes of Health Research, Heart and Stroke Foundation, Population Health Research Institute, Chanchlani Research Centre, McMaster Children’s Hospital Foundation, Wellcome Trust, UK Medical Research Council, U.K. Economic and Social Science Research Council, and the British Heart Foundation.