I consider Mondays really important for my health (The other days, well, those are a different story...).
Sometimes, if I'm going to yoga in the evening, I only eat raw foods and only drink water. If I'm not going to yoga (like today), then I simply don't intake anything except water for 24 hours.
I like to do this in order to start my week off right, to give myself a rest from digesting (or whatever you call the weekend's fare) and just to bring my body to a more balanced state. Additionally, I think it's important to go without food for a least a day per month to better understand those who have to on a regular basis. It's not some weird martyr mentality--I know my mini-fast isn't helping anyone else per se--but it's helping me understand 'what it's like,' even if for a mere day, the experience of which will come into play when I make decisions that hopefully and eventually help someone else.
Also, it's a great feeling of accomplishment the next day and it makes me appreciate tastes, flavors and textures so much more, even after such a small time off. I like how I feel and knowing that I just did my body a favor; I gave it a break.
The sucky part is staring at this mother fucking candy dish all day long.