Making the leap from how diet influences multiple generations of mice to its effect on humans is the next step. “We really have enough information now that this work needs to be taken to humans,” says Sarah Kimmins, Canada Research Chair in Epigenetics, Reproduction and Development. “What the father is exposed to, in terms of nutrition, has major ramifications for the health of his offspring—and it’s been a very understudied area,” she adds. “It’s just as critical to have a healthy father’s preconception as a healthy mother’s.”