As I understand it the redbull shouldnt keep weightloss from happening, but it will very likely mess with insuline and autophagy and other benefits.
As I see it, inspired by Dr. Fung, insuline response should ideally be kept minimal during weight loss. This will help the body take “weight” off from fat.
So all in all I would recommend sticking to water and black coffee. After getting used to sparkling water it doesnt really feel like you are missing out on to much.