Carla, Compared to Colby, Marshall looks like a fruitfly! He looks like a good normal weight. Chip (my black oriental shorthair) weighs about 7 Lbs. and has always been active and eats well etc. As long as his spine doesn't stick out, he'll live a very long time! The leaner the cat, they longer they can live without complications like diabetes etc. Marshall's mother could have had 40 kittens before having him for all we know. It's a miracle I even found him, and he is so healthy.