I was reading Jens thread 'I'm Pregnant' about morning sickness and fasting and was reminded of something I read recently in a link posted by Rawoman.
The following comes from this page http://www.rawfoodexplained.com/prenatal-care/care-during-pregnancy.html and says that you can fast for a couple of days to help deal with morning sickness. Let us know if it works!

The best diet for a pregnant woman (and, indeed, for everyone) is that which has a proper balance of carbohydrates, fats, and proteins. This can be obtained by eating a variety of mostly raw fruits with some vegetables, nuts, seeds, and sprouts. In eating this diet, the pregnant woman provides her baby with all the mineral salts, vitamins, and other food elements necessary for its proper growth and development.

The mother to be must also make sure she combines the foods according to food combining rules (no fruits with vegetables, no proteins with fruits, no starches with proteins, etc.) so she will assimilate the nutrients in these foods most efficiently and place the least burden upon her digestive facilities. Also, eating in an atmosphere of peacefulness as opposed to upset, in a well-ventilated environment, and in moderation are very important factors in proper nourishment.

Although most people will strongly advise against fasting while pregnant, it can be advantageous to both mother and baby to undertake a short fast (one to three days) during the early months of pregnancy. Many women, at this time, experience some form of nausea and discomfort and loss of appetite. This is not due to her pregnancy, but to her toxemic state. Needless to say, when there is no appetite, no food should be taken. Nature knows best and attempts to put the physiological house in order causing the pregnant woman discomfort and lack of appetite. A few days of fasting should restore comfort to the mother and enable her to eat without distress. Many people will tell the mother that harm will come to her baby and to her if she does not eat plenty of "good nourishing food" at this time, but what will she gain if she eats when she is nauseous and then ejects the food as soon as it is eaten? (See section on complications in pregnancy.)

A long fast during pregnancy, however, is not recommended. The fetus is growing and obtaining nourishment from the mother and can only go so long before deficiency will result.

Short fasts give the body a chance to adjust to the pregnant state. They allow the organs to rest and cleanse themselves to prevent abnormality of the fetus. Short fasts improve assimilation and utilization of nutrients from the food taken following the fast. Fasting also improves metabolism which makes nutrition more complete, not only in the intestinal phase, but also when it reaches the cell of the fetus.