Aww - what an adorable kitty you have! I love chubby kitties - although it is not healthy for them to get too chubby!
Try to monitor his food intake - give him portions - it is not only heathier but you will be able to notice fluctuations (in case he won't eat enough because he is hurt, etc..).
Also = "some people foods" are not healthy for cats. So you may want to cut back on that too.
And post more pictures!