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. Keep in mind that Phelps trains so much that he requires about 10,000 calories per day. Typical male high school swimmers require about 4,000 (you should verify this, I am going off of memory) while doing USA Swimming ("Year-round"). I'm not entirely sure what you mean when you say he is a professional swimmer? But as stated, I would check with the coach or whatever nutritionist is at his disposal.

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. Keep in mind that Phelps trains so much that he requires about 10,000 calories per day. Typical male high school swimmers require about 4,000 (you should verify this, I am going off of memory) while doing USA Swimming ("Year-round"). I'm not entirely sure what you mean when you say he is a professional swimmer? But as stated, I would check with the coach or whatever nutritionist is at his disposal.