Saturn generally restricts and contracts, so someone with capricorn rising or saturn in the first house will generally be skinny,bony even. Look to Jupiter for expansion, especially around the ascendant either natally or by progression or the progressed ascendant contacting Jupiter. This "expansion" is often caused by the natives eating habits and lack of exercise, Jupiter can expand the apetite for example, or could expand nervous/emotional tension leading to "comfort eating". Before you start wishing for a strong saturnian position in your chart, remember that along with the Jupiter expansion of the belly we also usually get an expanded sense of optimism, and find it easy to be "jolly", where as the saturnian frame of mind is more serious/less fun.
