He’s adorable and he has the most elegant sideburns!

Show rabbit pellets are typically high in protein and fat. You can cut back on pellets if you suspect that he’s a bit too chunky. Healthy young-ish rabbits practically only need good quality hay, perhaps with some pellets during molting. It’s good to weigh buns regularly and keep a weight diary. Esp the fluffy ones can gain weight over time without the human noticing it.

It’s not possible to tell if he’s chunky from one picture alone, as the others have said.