Overweight teenage boys may pass on genetic health risks to future children, study warns

Teenage boys who are overweight could be passing on harmful genetic changes to their future children, increasing their risk of conditions such as obesity and asthma, according to new research.

The study, conducted by researchers at the University of Southampton and the University of Bergen, Norway, suggests that weight gain during early adolescence may trigger epigenetic changes that affect the health of the next generation.

Researchers analysed the epigenetic profiles of 339 individuals aged between seven and 51. Each participant provided self-reported data on their body image during adolescence, enabling the team to investigate the impact of paternal weight changes during puberty.

The findings revealed epigenetic alterations in over 2,000 sites across 1,962 genes linked to fat cell development and lipid metabolism in the children of fathers who gained weight as teenagers.

Girls appeared more likely than boys to inherit these harmful changes, the study found.

Dr Negusse Tadesse Kitaba, lead author of the study, said: “The overweight status of future fathers during puberty was associated with a strong signal in their children’s DNA, which was also linked to a higher likelihood of those children becoming overweight themselves.

“Early puberty, when boys begin producing sperm, appears to be a critical window in which lifestyle factors can trigger epigenetic changes that persist across generations.”

Professor Cecilie Svanes, corresponding author, added: “These findings have important public health implications. They suggest that failing to address obesity in early adolescence could impact the health of future generations and widen existing health inequalities.”

Co-author Professor John Holloway concluded: “With childhood obesity on the rise globally, this research highlights the need to think long-term. The consequences are not just for today's population, but for generations to come.”