Our cat panky

We have a cat named Panky. He is definitely cute though he is a lazy type of cat. He loves to eat and sleep, that’s his daily routine in life. He never eats ordinary foods just like we eat but instead he chose to eat cat foods such like Friskies and Whiskas. Despite being spoiled Panky is sweet and loving. He always shows us how much he loves us back through waking us every morning with his sweet kiss. But one thing I worried about him since he only just love to eat and sleep and we never seen him on exercise yet; does it have a bad effect on his health considering that he never exercise himself?