so i saw another ball python that i assumed was quite older then mine to find out he was younger. so i started thinking my snakes under fed. ADVICE IS NEEDED

Hes 6 years old and ive owned him since he was 6 months. currently hes just shy of 4 feet. i feed him 1 medium rat every 2 weeks. and im seriously thinking this isnt enough. he never seems tempermental, i hold him daily, and he drinks lots of water. but when he sees food he wastes but a second to scarf it down.

how much do you all recommend him eating and if adjustmens are needed how should i go about in a safe way.