Goldern Algae Eater has enough food?

Hi, I have a Golden Algae eater in a heavily planted tank, he is active and cleans the tank very well, I used to have a lot of algae in the tank and the GAE always had more than enough food before. But recently I noticed that the tank is always clean and I don't see signs of algae in the tank. I'm just worried that he might not get enough food and I don't want to use commercial food since I don't want him to lost appetite for algae.
I have attached photos of his belly, can you tell whether he is full or hungry based on the photos? Thanks.

It is impractical to expect a fish to survive only off of algae growing in the tank. It is not going to end well. You need to feed him/her algae wafers and maybe even sinking shrimp pellets.That is a Chinese algae eater and they prefer a meatier diet as they grow, yours looks to be on the thin side to me. They can also become aggressive with other fish and grow a good 5+ inches. I had one CAE harassing my paradise gourami constantly. He had to go.