I fast for a few reasons:
1. Breakfast is not necessary, so skipping this meal saves me time in the morning. I already gotta worry about getting ready, feeding the dog+antibiotics, taking him out to pee, etc... one less thing to worry about.
2. Fasting for extended periods while in a ketogenic state accelerate fat loss. (the primary reason I fast)
3. I have noticed performance benefits with skipping the meal. (the cherry on top)
Really excellent guide: http://burnfatnotsugar.com/intermittent-fasting.html