The body habitus for them are «pear shaped» (relative excess of subcutaneous fat in hips, buttocks and limbs) and «apple shaped» (relative excess of abdominal fat) respectively. (md-health.com)
I had one 100 % outdoor cat that lived to be 16 years old and eventually died of geriatric kidney failure (after three months of subcutaneous fluid injections!) (best-cat-art.com)
There's the white coat and black skin as well as less visible differences like a thicker layer of subcutaneous fat layers and richer milk. (scientificamerican.com)