I think it all depends on how much muscle you have on your frame and how many preps you have under your belt. Oh, one more big factor is what kind of condioning you are coming out of the offseason in. I think no to very low carb diets work for people to kick start the diet or play catching up. I for one, have had to use low carbs to catch up in the pass, but now I prefer to eat well into the show and be fueled all the way to stage time! I have learned a lot by prepping myself, but I figured I can only learn more from others as well.
So many factors play a role, hard to pin point that this diet works better than that diet...trial and error with time under your belt tells us a ton..some peoples metabolisms are just more stubborn than others, so yes I would say keto works, yes I would say moderate carbs work, or even a longer balanced macro plan works, but hey I just decided to work with Alex this year to make the adjustments as needed and shoot me down a new path..loving it so far - eating really well into the show. Having some direction from an established prep coach is always good to help direct you down the right path.