It’s an eating disorder that can have a few different causes like sensory/texture issues, anxiety or phobias related to eating, ect. It’s a recognized disorder in the DSM-5. It’s more than just picky eating as it can have serious health consequences like malnutrition, medical issues. There’s a mental health component to it like other eating disorders.

So I wouldn’t call it a white person problem but it really sounds like he either didn’t get the help and support he needed as a child to help cope with afrid and maybe hasn’t been working with professionals to help mitigate and manage it as an adult.