A new study examines the impact of paternal diet on children's health-specifically, the influence of diet before conception. The researchers found that mitochondrial tRNAs (mt-tRNAs) and their fragments (mt-tsRNAs) play a key role in the inheritance of health traits by regulating gene expression. The study supports the hypothesis that acquired phenotypes throughout life, such as diabetes and obesity, are transmitted via epigenetic mechanisms across generations.