Do swimmers need to eat a special diet?

I have a 17-year-old son who is a professional swimmer. I’m wondering, does he need to follow a particular diet or can he eat anything? In this photo from Michael Phelps’ Instagram it looks like his diet isn’t too restrictive. yes he should be on the seefood diet see food..eat it i wont say how far or how much i was eating at 17, but lets just say that the numbers were astr0nomically huge and our underwater weighing to determine body fat composition said i was 10.9%

I have a 17-year-old son who is a professional swimmer. I’m wondering, does he need to follow a particular diet or can he eat anything? In this photo from Michael Phelps’ Instagram it looks like his diet isn’t too restrictive. yes he should be on the seefood diet see food..eat it i wont say how far or how much i was eating at 17, but lets just say that the numbers were astr0nomically huge and our underwater weighing to determine body fat composition said i was 10.9%