SIDE EFFECTS Some people feel weak during parts of the FMD. Others say they feel more energetic. Some patients complain of light- or average-intensity headaches. This effect is usually greatly reduced by day 4 or 5, and eliminated entirely by the second or third FMD cycle. Most people feel hungry during the first few days of the FMD. This effect is greatly reduced by day 4 or 5 and on all days during the second or third FMD cycle. Some people suffer a slight backache that disappears once they resume a normal diet.
