A study in PLOS Genetics suggests that a mother’s genetic makeup may influence her child’s weight through mechanisms that extend beyond inherited DNA. Researchers from University College London analyzed genetic and health records from 2,621 UK families enrolled in the Millennium Cohort Study, tracking children from birth to age 17.
The team assessed parental body mass index (BMI) alongside genetic data to separate direct genetic inheritance from indirect genetic influences. These indirect effects, referred to as genetic nurture, occur when a parent’s genes affect the developmental environment rather than being physically passed to the child. Maternal genes could influence the womb environment, dietary habits, or other behaviors that shape a child’s growth and metabolism.
While BMI from both parents correlated with a child’s BMI, the paternal link was explained almost entirely by inherited genes. Maternal BMI, however, remained a significant predictor of a child’s weight after accounting for direct genetic transmission. “Mothers’ genetics appear to play an important role in influencing her child’s weight over and above the child’s genetics,” said lead author Liam Wright. “In addition to the genes mums directly pass on, our findings suggest that maternal genetics are instrumental in shaping the environment in which the child develops.”
Dietary patterns were also examined at multiple ages through self-reported intake of fruit, vegetables, fast food, and sugary drinks. To address the limitations of BMI as a proxy for body fat, the study incorporated additional adiposity measures, including fat mass.
Wright emphasized that the findings are not about attributing blame. Instead, they could inform strategies to support healthier family environments. He noted that interventions aimed at reducing maternal BMI, particularly during pregnancy, may help lower intergenerational obesity risk.
NHS figures show that 27% of UK children aged 2 to 15 were classified as overweight or obese in 2024.
Publication Details
Wright L, Shireby G, Morris TT, Davies NM, Bann D (2025) The association between parental BMI and offspring adiposity: A genetically informed analysis of trios. PLOS Genetics. 21(8): e1011775. https://doi.org/10.1371/journal.pgen.1011775
The team assessed parental body mass index (BMI) alongside genetic data to separate direct genetic inheritance from indirect genetic influences. These indirect effects, referred to as genetic nurture, occur when a parent’s genes affect the developmental environment rather than being physically passed to the child. Maternal genes could influence the womb environment, dietary habits, or other behaviors that shape a child’s growth and metabolism.
While BMI from both parents correlated with a child’s BMI, the paternal link was explained almost entirely by inherited genes. Maternal BMI, however, remained a significant predictor of a child’s weight after accounting for direct genetic transmission. “Mothers’ genetics appear to play an important role in influencing her child’s weight over and above the child’s genetics,” said lead author Liam Wright. “In addition to the genes mums directly pass on, our findings suggest that maternal genetics are instrumental in shaping the environment in which the child develops.”
Dietary patterns were also examined at multiple ages through self-reported intake of fruit, vegetables, fast food, and sugary drinks. To address the limitations of BMI as a proxy for body fat, the study incorporated additional adiposity measures, including fat mass.
Wright emphasized that the findings are not about attributing blame. Instead, they could inform strategies to support healthier family environments. He noted that interventions aimed at reducing maternal BMI, particularly during pregnancy, may help lower intergenerational obesity risk.
NHS figures show that 27% of UK children aged 2 to 15 were classified as overweight or obese in 2024.
Publication Details
Wright L, Shireby G, Morris TT, Davies NM, Bann D (2025) The association between parental BMI and offspring adiposity: A genetically informed analysis of trios. PLOS Genetics. 21(8): e1011775. https://doi.org/10.1371/journal.pgen.1011775