We always love a good “fat dads make fat kids” story, but this one didn’t get full-on ORLY status because of the twist.

Some smart dudes at the the University of Adelaide’s Robinson Institute Research Centre for Reproductive Health tested mice and found that the sperm of overweight fathers actually passes the obesity trait down to children.

These results were presented at the World Congress on Human Reproduction in Melbourne, presumably in the morning so it would ruin everyone’s buffet lunches.

So far in the fat mice, daughters seem to be more susceptible than sons. Also – fathers that shape-up and lose weight are less likely to pass it onto their kids. Next step – human testing.