One of my guinea pig is a very fat and the other two are very healthy weights. Last time she was checked at the vets, she was 1200 grams. She had been on a diet but and we think she has lost a little bit of weight but are there any more ideas on how she could loose weight? She and her sisters share two small handfuls of pellets everyday, some hay and umlimited grass as they have a run. We do not want the other two to get to thin as well as one of them needs to eat eat enough food as she was once terribly under weight.