I recommend fasting with just straight electrolytes and no calories. Just magnesium, potassium, and sodium. Gatorade will spike insulin and negate a lot of the benefits you would get from a fast (besides the benefits of protein fasting)
I had plenty of Gatorade Zero on my 50 day fast and definitely think it made it easier to stick to it. I wouldnt call it a fast though if I had regular Gatorade as the sugar and calories would pull you out of ketosis (and also likely trigger hunger making it harder to keep going). Still, my 50 day fast earlier this year had me lose 61lbs, and it definitely helped me stay on track.