American Guinea Hogs, being a landrace breed, come in all shapes and sizes.
For example, in the photo above there are three, chunky monkey, lard-type piglets on the right and one long, lean, bacon type on the left. These litter mates are four weeks (not months) old. We try to raise both types here on our homestead. If, however, If there is a body type you like, select for it. Eventually, you will be consistently producing that body type on your farm.