Fasting

Yesterday was MahaShivratri - it is a very auspicious night. That is the one day out of the whole year that I keep a fast. I've been doing that for years now. I wonder why it is that I feel like fasting. I dont normally believe in it so much, mainly because there are certain allowed foods for a fast. And a lot of those allowed foods are heavier than the usual foods we eat. So then I think - what is the point of a fast. So when I fast on Mahashivratri, I usually do it by having just water. I think that fasting once a year is certainly ok and gives me a chance to observe if I can have the control over myself for at least that one day. What I observed yesterday and over the years when I fast for Mahashivratri, I find interesting. I've found that once I decide to fast, usually I dont feel physically hungry very much, my energy level is ok. But what drains me the most is the mental feeling that I've not had food. Mentally, I am thinking of food and that is what saps a lot of the energy out of me. That makes me wonder - if I can actually believe that I'm ok without food, would I have a lot more energy? Do I eat foods because my body needs it or because I have the craving for taste. Would I make better food choices if I was able to get rid of this craving for certain tastes ?