Welcome to Gaia! ::

I fast a few times a year for religious purposes. What my clergy suggest is to eat a light but nutritious meal before starting the fast -- a salad, some sort of protein, some sort of starch, low on fat and especially on salt, which makes you thirsty. Once the fast is over, you should eat a light mini-meal as well, but this time it should have some salt so that you'll be reminded to drink as well as eat. After the light mini-meal has had a chance to sit for half an hour to an hour, eat another light meal.

You're right, not eating on a regular basis can really shred one's metabolism. Unless fasting for a day for religious purposes, one should try to eat at least a little bit throughout the day. If you truly don't feel up to proper eating, at least promise yourself a protein serving (one egg, one to three ounces of meat or fish or fowl, one to two ounces of non-fat cheese) and a vegetable or fruit serving, three times a day, and six or more glasses of water per day. Write it down if you have to, to make sure that you get it. Also, don't go longer than six hours without eating unless you're fasting for that one day -- that, too, can cause your metabolism to slow down or shut down.

Also, the binge-purge thing only has two real outcomes, if allowed to go far enough. One -- eat a lot, then throw up -- is bulimia. The other -- starve all day, eat huge at night -- leads to diabetes.