Not eating anything for a day has its own benefits. Its is routinely suggested by astrologers to improve life of a person.

     Japanese researcher Yoshinori Ohsumi won a nobel prize for showing the benefits of fasting. Science today calls fasting as autophagy. Fasting helps improve insulin sensitivity. There were 382 million diabetic patients worldwide in 2013 which could benefit from fasting. Fasting helps rest the digestive system. The body has a mechanism to cleanse and detoxify the body by converting the dead cells and excess fats in your body into energy. This in turn promotes longetivity in natives. The metabolism rate improves drastically after fasting. Fasting has been shown effective to improve brain functionality. The immune system is also improved drastically due to fasting. It can also improve acne, pimples and other skin problems. Fasting also helps improve blood pressure if intermittent(one time eating) is done. Caution as too much fasting lowers blood pressure. 

     Vedic literature tells to fast in a certain way. Say people with Mangal Dosha are advised not to consume salt on tuesday and one time fast or no eating is prescribed. That is partly due to fact that sodium in salt increases blood pressure and chloride increases body irritation. This increases anger in turn, a typical trait among people with Mangal Dosha. When you fast on Full Moon and observe satya narayan upvas and only eat suji ka halwa you are never informed that Moon causes tides and ebbs in ocean as well body fluids. Naturally on full moon the body fluids increase production thereby increasing blood pressure and anger. Milk and Ghee both have high level of potassium which help regulate blood pressure. Full Moon also increases kidney functioning and milk and sugar help restore kidney fluids. 

     Fasting done on two navratris and shravan month also has importance. The two navratris are the time when season's change from summer to mild winter or from spring to summer. Atmospheric pressure, temperature and winds change. The body cannot handle the sudden fluctuations in weather and often falls sick. Fasting is used to negate the ill-effects of weather change and resistance in body improves due to it. Shravan is the month when there are continuous showers along with humid and damp weather. The body gets sick without proper exposure to sunlight. Fasting helps negate these ill-effects. In southern India and few parts of northern India people do chaturmas a fasting for four months between July to October. Conditions in India change continuously from being extremely hot and humid to cloudy and damp during these times and fasting removes the ill-effects of such weather change on body. Also consumption of less food and more juices in chaturmas promotes replenishing of body. 

     Fasting was not just a fancy thing invented by ancient people. Much of it was based on science. Remember to understand the reason and it would do more good then you could possibly imagine. 

     Fasting Good for Brain: http://chaddsfordchiropractor.com/intermittent-fasting-boosts-your-energy-and-brain/

     Fasting Good for Insulin: http://jap.physiology.org/content/99/6/2128

     Fasting Good for skin: http://skinverse.com/fasting-for-better-health-and-skin/

     Benefits Of Fasting: http://www.lifehack.org/articles/lifestyle/10-benefits-of-fasting-that-will-surprise-you.html

     Benefits of Fasting on Digestion: http://www.allaboutfasting.com/benefits-of-fasting.html

     Benefits of Milk: http://www.milk.co.uk/page.aspx?intPageID=73