We have two female Guineas (2.5 years old) and they're really quite podgy and I'm wondering if they are perhaps too podgy!
They live outside in a massive hutch with permanent access to an equally massive run so are hardly cooped up. They get fresh food (cabbage, cauliflower and the like), pellets, hay and obviously grass.
They're very active and can happily jump over the ridge to get from one part of the run to the other.
The reason I ask is we recently looked after some male Guineas and my girls were considerably larger both in length and girth!