The fitness guru was the latest celebrity to do the hilarious Get Out Of My Ear segment, which sees stars wearing ear pieces as the show's presenters Ant and Dec tell them what to do and say.
In an teaser clip shared ahead of his segment on Saturday, 18 March, Wicks is seen taking a cauliflower from his fridge and biting into it, as a man nearby looked on.
Trying to compose himself as Ant and Dec giggle in his ears, Wicks then offered it to the man, saying: "Have a little bite on that side."
"That's it, have a big one," he went on, as the unsuspecting man took a huge bite and Ant — hidden in a secret room — roared with laughter.
Wicks, 37, was then told to say that when he was munching on the crunchy veg he felt as if he was eating brains.
"I'm a zombie, give me the brain," he quipped, as he tried to keep a straight face.
This weekend's programme will also see Hollywood star Toni Collette as the guest announcer and will include the next instalment of Ant and Dec's gripping mini-show, Murder At Bigwig Manor.
Jake Shears will be the star of the End Of The Show Show.
Ant and Dec's Saturday Night Takeaway returned to TV screens for a new series in February.
The next instalment airs on Saturday (18 March) night on ITV1 and ITVX at 7.15pm.
Watch: Ant and Dec tease 'brutal' I'm A Celebrity All-Stars series