Just finished my first 24 hour fast (from 8pm Sunday to 8pm Monday). Going into it, I thought it would be very difficult, as typically I eat something every 2 or 3 hours while awake (trying to gain weight). When I don't eat for on my regular schedule, I start to get hungry and uncomfortable.

Natalie gave me a great piece of advice- not to eat in the morning, but to begin my fast the night before. This made all the difference- I didn't really get too hungry at any point during the day. I felt more alert, more energetic and was more productive at work (as I had a bunch of extra time that I would usually devote to eating 2 full meals and 2 snacks while at the office). I drank a ton of water (about 4-5 liters), that helped a lot.

I think I'll keep this up for a month (Sunday night to Monday night) for the next month to see what it does to my workout performance and weight gain goals

Found some great IF links as well:

http://www.proteinpower.com/drmike/intermittent-fasting/fast-way-to-better-health/

http://www.proteinpower.com/drmike/intermittent-fasting/protein-power-verses-intermittent-fasting/

I couldn't find it on his website, but in a couple of his podcasts Robb Wolf says that about 16 hours is the optimal time span for a fast. Past that your body starts using your muscle for fuel. Something changes again at around 48 hours, but who wants to go that long without food
Skipping breakfast a couple times a week works well for me. It doesn't feel as hard since most of the fast is spent sleeping.

That's great info Stefan, I'll try to confirm this- I don't think any of us want to lose muscle mass