Be cautious! For me, my aim is to find a diet that's healthy and I can stick with. So far, LCHF's working. I'm losing weight at a nice, steady pace and I'm getting fewer cravings for bread/spuds/pasta/rice than I did when I started. Basically finding enough variation in my diet from tips & suggestions here to keep it interesting.. Which means I'm more likely to stick with it once I've hit my target weight. Water fasting, or intermittent starvation is... boring, so might be harder to keep up, and temptation to overeat on non-fasting days. I used to spice it up a little by adding a dash of fresh lemon or lime juice though to give the water a bit of taste.