Chicago: Water fasts may help with weight loss but it's unclear how long it will remain, according to a study from the University of Illinois at Chicago. In water fasts participants consume only water for a period of time.
The researchers also found that the other metabolic benefits of water fasts, such as lower blood pressure and cholesterol, seemed to disappear shortly after the fast.
The study was published in Nutrition Reviews.
According to Krista Varady, professor of kinesiology and nutrition and the study's lead author, there do not appear to be any significant negative effects for those who adhere to water fast or a similar fast in which they consume very few calories per day.
Varady, an expert on intermittent fasting, said she wanted to study water fasting because she suddenly started getting contacted by journalists last fall who wanted to hear what she thought about it. She figured if she was going to comment, she should investigate the existing research.
The new paper is a literature review of eight studies on water fasting or Buchinger fasting, a medically supervised fast that is popular in Europe where people consume only a tiny amount of juice and soup a day.
Only a few of the studies in the review tracked whether participants gained back the weight they had lost once the fast ended. In one of those, people gained back all they had lost in a five-day water fast within three months. In two other studies, only a small amount of the lost weight returned, but those studies encouraged participants to restrict their calorie intake after the fasts ended.
In contrast, it was clear that the metabolic benefits of the fasts disappeared soon after the fasts ended. Improvements to blood pressure, cholesterol and blood sugar levels were short-lived, returning to baseline levels quickly after participants started eating again.
The most common side effects of these prolonged fasts were similar to those from intermittent fasting, Varady said, such as headaches, insomnia and hunger. There were no serious negative effects in the studies, such as metabolic acidosis or death. (ANI)
