The `America`s Got Talent` host was hospitalised two weeks ago with mild kidney failure - which he says was due to an overdose of protein, medication he was taking and a lack of proper sustenance - and though he is on the road to recovery, he has had to overhaul his eating habits.
Nick said: "I`m feeling good, I`m in the office, I`m grinding, the only thing that sucks is that I`m on the renal diet.
"It`s all about healthy living and fuelling your system, but I don`t get to eat the things that I like to eat. You`ve got to stay hydrated and eat fruits and vegetables for breakfast."
Explaining he has had to give up his favourite Lucky Charms cereal in favour of oatmeal, he added: "Not even the good oatmeal. Real oats, like horse-feed stuff -- but it`s cool. I`ve got to start to love it."
Nick - who has eight-month-old twins Moroccan and Monroe with wife Mariah Carey - will gradually be able to relax the strictdiet but in the meantime, he is turning to hot sauce to make his meals more exciting.
He told MTV News: "Right now I`m still on the strictdiet and I can`t have any sodium, but as a couple of weeks go by and everything gets levelled out, then I can start having low sodium.
"I can still have Tabasco sauce, so I`m excited about that because I love hot sauce. I`ll be putting Tabasco sauce on carrots, like, `This tastes delicious!` "