What is Upvasa (Fasting) and what are the advantages of it?

In Hindu religion, Doing fasting is a very significant. Fasting is also occurs in other religions like Jain, Buddhism and even in Islam. Question is why fasting is performed and what are the significance of it. In Hindi and Sanskrit, fasting is called as "UPVAASA". Actual meaning of UPVASA means second type of living. First type of living is as we live life normally like eating, sleeping and doing social activity. In second type of living means living near to self and identifying self. Another way we can living near to almighty. If we say, bringing changes in daily routine is called UPVASA. UPVASA doesn't mean only fasting or avoiding food to eat. It means bringing changes in normal routine work.
          For example, as we work daily in offices or factory and take a leave on Sunday for relaxation and regain our energy. Similarly, Ancient sages and saints were so intelligent that they knew, human body needs relaxation after a continual work for better health. Hence, they advised society to do this and for spiritual development, they connect this to god. Therefore people started to please God and fulfillment of there wishes. Peoples gained spiritual upliftment and remain healthy. In Ayurveda, it is advised to do fasting once in a week for living healthy.
           The doctors and bio students must know that some part of glucose from digested food get stored in liver in forms of Glycogen for further utilization. When the human body will not get food in time, then for proper functioning of human body, Glycogen stored in liver again get converted to Glucose and utilized. Due to this human body become healthy. Such types of process can be seen in animals and other living thing in another form.
         Now a days, people don't understand significance of fasting. They eat more than required quantity. Due to this, peoples suffers lots of diseases like diabetes, obesity and over weight. Even daily they eat lots of fast foods, which are not healthy. If they feed on fast food, so they should do fasting once in a week. On eating fast food, digestive system of human body do hard work to digest fast food and it take much time to digest. Hence by doing fasting, digestive system get relaxation and regain it functional activity.
              Basically there is two types of fasting called as 1) Kastha and 2) Nistha .
In Kastha fasting, Strictly food is not eaten from first day sun rise to second day sun rise. In Nistha fasting, Food is not eaten during day time but fruits and cow milk is allowed to eat after sun set. Fruit is used to eat after sunset because fruit is easily digestible.
            As I said above that UPVASA meaning is not only to stop eating food for a day here. UPVASA means to controlled anything that you do daily. Another name of UPVASA (Fasting) mean VRATA, some people in Hinduism do Nirjala ekdasi, in which they don't drink water for that day. Not drinking water, for that day, digestion as well as activity of Urine system get relaxed and the functionality of this system increases. During performing of such UPVAASA or VRATA, there is the condition not perform any physical activity and not to go out from home to get exposed to strong sun rays. Another example is MOUN VRATA, in which the person not speaks out or talk with any person. We must know that by talking, we losses lots of energy. So in Hinduism, people performs MOUN VRATA, to control their energy losses. Mahatma Gandhi was also doing MOUN VRATA once in a week.

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