My son only wants to drink red bull. he's only 2 years old and im concern?

My sister started giving him sips of red bull when he was a year old now he's two and wakes up demanding sometimes sneaking red bull to his room. I've been observing his behavior and so far he has about three-four redbulls a day. I want to trust that he will do the right thing and wouldnt need me to hide the red bulls but he's a sneaky sneak. I need to get him off of red bull but i dont think its healthy to cut red bull cold turkey. What could be a better solution to his "addiction"