Surprisingly, since I've started intermittent fasting I've increased muscle mass (up 10 pounds from 205 to 215), decreased body fat (down 3% from 14% to 11%), increased explosiveness (set a personal best with a clean and jerk of 253 pounds a few months back), and decreased the amount of time I've spent training (down from 7.5 hours per week to 2.5 hours per week).
Cons: On the flip side, if you have a hard time handling cheat days the healthy way, this method might not be for you. Additionally, because the plan is pretty specific and the fasting/feeding schedule varies from day to day, this method can be a bit confusing to follow. (However, the plan does come with a calendar, noting how to fast and exercise each day, which may make it easier.)
Initial human studies that compared fasting every other day to eating less every day showed that both worked about equally for weight loss, though people struggled with the fasting days. So I had written off IF as no better or worse than simply eating less, only far more uncomfortable. My advice was to just stick with the sensible, plant-based, Mediterranean-style diet.
There’s a ton of incredibly promising intermittent fasting (IF) research done on fat rats. They lose weight, their blood pressure, cholesterol, and blood sugars improve… but they’re rats. Studies in humans, almost across the board, have shown that IF is safe and incredibly effective, but really no more effective than any other diet. In addition, many people find it difficult to fast.
Not only that, but growth hormone is increased during fasted states (both during sleep [5]and after a period of fasting). Combine this  increased growth hormone secretion:[6], the decrease in insulin production (and thus increase in insulin sensitivity [7]), and you’re essentially priming your body for muscle growth and fat loss with intermittent fasting.