Has anyone heard of a male rat essentially starving himself to death to keep the female healthy while pregnant?

supply isn't an issue they are loaded with food in the cage; it does seem to be a possible dominance issue (shes domming him). as for illness the only apparent sign is his underweight and lethargy, he was little thin but otherwise fine maybe 5 days ago, he played dentist and had his PB and was happy. Right now they are separated and his cage is stocked with his favorites.