When I added the occasional IF (18 to 24 hour fasts 3 or 4 times a month) I also worked to try to eliminate snacking between meals. This essentially made the 12 hour fast a regular daily thing for me. It didn't happen everyday - but it did happen more often than not. I saw clear and immediate results with my BG. My baseline BG dropped by about 20 points and since then my post prandial BG readings have been stellar. I rarely get a reading above 120 at the peak postmeal. Most readings are below 100. 9 months into this WOE (before adding IFs) I was still getting FBG and pre-dinner BG readings in the 100 to 110 range. So I'm thinking that IF did wonders for my insulin resistance.

I've only done one longer fast (6 days) and I have an interesting observations about it. I had started lifting weights for strength and I decided to continue during the fast. At the time I was doing 2 days of lifting (different muscle groups) and then I took a recovery day.

When I started the fast my recovery day was day 1. I did my normal lifting routine on the next two days. Strength was fine both days. I completed my sets - just barely getting them in before failure. I was lifting at my max capabilities for 3 sets of 6 to 8 reps for each lift.

I took my off day on day 4 of the fast. To that point the fast was going fine. No issues at all. I actually find fasting easer to do than to under eat on a given day.

Day 5 and day 6 of the fast were lifting days, if you want to call it that. I felt fine, but I could not come anywhere close to getting all of my reps in on my lifts. On the first sets I was getting 6 to 8 reps for each lift, but it felt like the last set. By the 3rd sets I couldn't get but 1 or 2 reps in. It was clear to me that very little recovery had occurred since my last session. I was much weaker than I otherwise would have been given my past performance with this routine.

I ended the fast at day 6. It was supposed to be a 7 day fast, but I just wasn't feeling it. I can't say that I enjoy fasting. I don't. I'd rather eat. But it wasn't too hard, either. I was tired of doing it and ended it a day early. I ate plenty of protein.

What I find most interesting about this experiment is what happened next. First of all, I did tend to make-up eat. I was hungry and I ate. I was surprised to find that when I resumed my weight lifting routine after my off day I had regained all of my strength and then some. Getting all 3 sets of each lift in pretty easy. The bounce back was amazingly fast. I expected it to take longer. After another day off I did 2 more days of my weight routine. It was easier still. I upped the weights across the board for the next round a few days later. I don't know how long the boost of HGH floats around in your body, but it seemed to be above normal in that week following the fast.

A week or two after the fast I was lifting more weight and seeing the results in the mirror. That last part is subjective. But lifting a higher amount of weight across the board is not. I was stronger in a short window of time. Was it the fast? Was it the compensation eating that I was doing for the week after the fast? I can't say for sure. What ever the case, I appeared to bulk up much faster as a result of the fast compared to what had been happening prior to the fast.

I did this over the summer. I haven't done a fast longer than 2 or 3 days since then. I just don't enjoy fasting any longer than that. I haven't learned to properly end a fast yet - so there is no point to it as far as weight loss goes. I just compensate eat for the next day or two. But I don't think losing lean muscle was a problem. If anything I ended up gaining some as a result of the longer fast.