Recent research by scientists at University College London reveals that the risk of obesity in children is largely related to genes inherited from their parents—especially from the mother. 

The findings, published in the journal PLOS Genetics, are based on an analysis of genetic and health data from 2,621 families in the United Kingdom who participated in the Millennium Cohort Study, a long-term study of individuals born in 2001–2002. Researchers examined how the body mass index (BMI) of parents and associated genes influence children’s weight, diet, and health from birth up to 17 years of age. Six key developmental stages were analyzed: ages 3, 5, 7, 11, 14, and 17, taking into account factors such as frequency of fruit, vegetable, fast food, and sugary drink consumption. 

The research team, led by Liam Wright, analyzed genetic data, dietary habits, and BMI of mothers, fathers, and children. Special attention was given to the so-called genetic nurture effect—where parental genes, even if not inherited by the child, affect the child’s development through the home environment, such as food preferences or lifestyle. 

The study found that while both mothers’ and fathers’ BMI correlate with their children’s BMI, the greatest influence comes from genes inherited from the mother. Moreover, maternal genes not passed down to the child can still impact the child’s body weight during adolescence. For fathers, this additional environmental effect was much smaller. 

The authors emphasize that ignoring genetic factors may lead to overestimating the role of the environment in shaping body weight. They suggest that effective public health policies focused on reducing obesity among women could realistically improve the health of future generations. 

The study was funded by the Medical Research Council, Economic and Social Research Council, and Norwegian Research Council.