(borrowed from Abe Bonowitz's guidelines for fasting, with Amy's suggestions added)These are designed for long fasts like for 56 hours but can be modified for the 24 hour fasts. So use your best judgement in this case.

General Concerns
• The body uses a tremendous amount of energy resting and assimilating foods. Giving your body a rest from this process allows it to cleanse and balance itself. A modified fast is considered by many experts to be an excellent way to give the body a chance to regroup or fight minor illnesses like colds.
• When done carefully and with deliberation, fasting is not really a health risk at all. Of course, this is only true for people who are generally in good health. Diabetics, and those on anti-inflammatory drugs or steroids should not fast. Check with your doctor before any significant alteration of your diet, but particularly If you are over 50, on any medication, or if you have other specific health concerns.
• It is important to stay conscious of your own health status during your fast. If you've ever not taken care of yourself before, as most college students are prone to doing, you know how you feel . . . a little disoriented, a little run down, etc. Some of this is to be expected with a fast, but keep it realistic and let people know if you're really starting to crash. Look out for each other. :-)

Drinking Guidelines
• AT LEAST 4 Liters of water per day. This really can't be ignored. Buy one of the little waterbottles (they're usually half-liter), and drink 8 of them per day. Water's important in preventing dehydration, maintaining your health, and it also works as an appetite suppressant (making fasting easier). I really can't stress the significance of this enough.
• make an effort to consume a moderate amount of Gatorade/Powerade or other such drinks. These sorts of drinks are important because they help keep your electrolytes in balance. By the second day or so, you'll probably want to dilute them . . . they can seem pretty strong after not having had any food all day. make a mixture of water and powerade and let it help you in multiple ways.
• Juices - always good for flavor and nutrition. you're probably going to want to dilute juices as well to make them slightly less acidic. some people don't notice it...i've found it pretty apparent by about 24 hours into the fast.
• smoothies and such things are on a personal basis - they can be great for making it feel like you're eating something when you feel unusually hungry.
• AVOID CAFFEINE...another thing that can't be overstressed. when your body doesn't have food, the caffeine in a can of soda can really do unique things....you really don't want to get in that sort of situation while fasting (think drinking a few cans of soda at 4 in the morning and then multiply it...not fun). Along those lines, soda really isn't a great thing. if you want it, i'm not going to stop you obviously, but the various characteristics of it will really be exacerbated during a fast (acidity, carbonation, etc)
• likewise, AVOID ALCOHOL...i don't need to explain the multiplier effect. maybe people with a higher tolerance than me would be able to manage something alcoholic during a fast, but i really don't recommend it. the kick's stronger at both ends (during consumption and morning after). of course, we're fasting during the schoolweek, so i don't really need to say this.. :-)

Tips for breaking the fast
• It is very important not to "pig out" upon ending your fast. This is bad for the body and can make you ill. If you have enjoyed a spiritual experience with your fast, it is particularly important to re-enter the world of food slowly and deliberately. Think bland and eat slowly. (vegetable soup, rice dishes, and such things...generally non-ethnic vegetarian or vegan cuisine's good).
• Be careful with yeast products. If you haven't had yest in several days, it is best to go back into it slowly. Bread is hard on the stomache and digestion system if you haven't had it in a few days. It is easy to eat too much bread after a fast, so be careful.

Tips and guidelines for fasting
• Most people find it useful to start eating less, and lighter foods, in the 2-3 days prior to the fast.
• Drink continuously . . . ALWAYS carry something with you. Most of the times, let it be water. But have something with you whether you're walking across campus or down the hall. The more you drink water, the less you feel hungry (it really does work). Also, the most important health concern of dehydration is extremely preventable.
• One of the most difficult things about fasting is giving up food - not in our body, but in our head. Some folks find themselves fantasizing about food. Be realistic and acknowledge that at times, it can be difficult. If you deny the fantasy, it can get stronger. You might find it useful to enjoy the fantasy, and then turn again to the reason that you are fasting.
• Some folks experience hunger pangs for the first day or two. This will pass, and by the third day your body will typically adjust. When experiencing hunger pangs, you may find it helpful to acknowledge that you are hungry, and then turn your thoughts to the reason that you are fasting. Keep drinking. Drink some more.
• Another difficulty with fasting is texture deprivation. I'm going to be honest . . . .After a day or two, you may get a touch of diarrhea. You're also going to be peeing on a fairly constant basis. Know where bathrooms are and make sure you use common sense (for example, go to the bathroom before walking across campus).
• you'll probably want to tell your professors that you're fasting . . . that way, they know when you leave to go to the bathroom that you're not deserting class. also, if you happen to arrive late or such things, they'll be a little more understanding.
• as we're all college students, a few guidelines for going about your day to day life - take more time doing what are typically simple things - walking across campus, walking up stairs, and all those sorts of things . . . you just need to be a little more aware of the fact that you're going to be a little weaker than you usually are.
• By the time you get to the third day, you may begin to feel a little "high" from the lack of food. This is natural. It is important to be a little more aware of yourself while walking or doing anything potentially dangerous, like carrying stuff, or driving. Some people use this "high" as a special place in which to meditate, and enter into solidarity with others.