New York: Female children born to obese fathers are at high risk of being overweight at their birth and throughout childhood, says a study conducted in mice. The findings showed that female mice pups born to obese fathers are also prone to the delayed growth of their breast tissue as well as being at increased risk of developing breast cancer. Obesity changes the microRNA (miRNA) signature -- epigenetic regulators of gene expression -- in both the father's sperm and the daughter's breast tissue, suggesting that miRNAs may carry the epigenetic information from obese dads to their daughters. "This study provides evidence that, in animals, a fathers' body weight at the time of conception affects both their daughters' body weight both at birth and in childhood as well as their risk of breast cancer later in life," said lead researcher, Sonia de Assis, Assistant Professor at Georgetown University in the US. The miRNAs were identified to regulate the insulin receptor signalling, which is linked to alterations in body weight and other molecular pathways that are associated with cancer development. "Our animal study suggests that those epigenetic alterations in sperm may have consequences for next generation cancer risk," de Assis added. Eating a balanced diet, keeping a healthy body weight and lifestyle is imperative for both men and women not only for their own benefit but also to give their children the best chances of being healthy, said the paper published online in the journal Scientific Reports. The next step is to see if the same associations regarding breast cancer risk hold for daughters of human fathers who are overweight around the time of conception, the researchers concluded.