Usain Bolt's love of junk food -- especially chicken nuggets -- has been well documented, but now at the age of 28, the Jamaican is ready to change the way he refuels.

"Food wise, I have to eat a lot more vegetables," he explained to CNN's Amanda Davies, almost sounding like a boy being told by his mother to finish his greens.

"I have to cut junk food out. I think that's one of the biggest things for me, because I get a lot of urges at late nights, just to eat junk food. For me, that personally is one of the biggest sacrifices."

And it really is a sacrifice given Bolt estimates in his autobiography "Faster than Lightning," that he had devoured 1,000 McDonald's chicken nuggets during his 10 days in Beijing -- a whopping 5000 calories and 300 grams of fat a day, all because he found Chinese food "odd."

Vegetables may be a new addition on the Bolt menu, but don't expect him to be cooking them.

"I can't cook, that's the one thing I can't do, though I can make scrambled eggs," he confessed ahead of the Anniversary Games in London.

But if you ever feel guilty about breaking a diet, you shouldn't, as even the world's greatest athletes are still prone to the odd slip-up.

"Sometimes you do think about just going out or just not training, or just eating a million hot wings. It's hard sometimes, because you crave it, because you're used to doing a certain thing.

"It's hard to just walk away and not slip up sometimes. So it happens, but I try to not make it happen on the regular. I try to just contain myself as much as possible."

As well as resisting deep-fried chicken temptations, Bolt has also become more conscious of his body clock and whether that is helping or hindering his athletic performance.

"Oh, I think it's just not sleeping [is my biggest weakness.] I'm so used to staying up at night, especially playing video games or just watching movies.

"I think that's one of my hardest things to overcome, trying to go to bed early. Even when I want to sleep, I tend to try to fight the sleep and not go to bed."

It would appear Bolt's new healthy diet and early bedtimes are starting to pay off, as he recorded his fastest time of the season -- 9.87 seconds -- at the Anniversary Games to take the gold medal in the 100m on the same track he tasted Olympic glory on at London 2012.

(CNN)