I've been doing intermittent fasting for awhile now.... I keep my fasting window between 16-18 hours on most days. I know some might take exception with this but when I eat I'll eat pretty much whatever I want. I'm not gorging myself but I'm not putting forth much of an effort on only eating this or that. And the weight still just drops off. It's crazy... something I never would have expected. Anyway - some days I'll just take off entirely and eat whenever and whatever. But those days when I'm eating sweets during a time when I'm typically fasting I'll notice that I'll get acne pretty quickly. Say someone brings cupcakes into the office: I might decide to put off fasting and have one (five). I've begun to notice that very shortly after doing that I'll get a few spots of acne mainly on my shoulders and upper arms. It's interesting to see how much more sensitive my body is to sugar now.