Quite a number of friends approached me during the last lunar eclipse of January 31st to understand the logic (especially in light of Ayurveda) behind why the ancient texts advised to keep fast during eclipse. So here is absolute logic to it.
To begin with, we all need to understand that it is sun and more specifically sunlight that governs all the metabolic triggers in a living body. It is the morning sunlight (direct or indirect) which falls on our pineal gland (called as third eye in the ancient texts) situated in the centre of our forehead that triggers current (called as pitta, to be precise sadhak pitta in Ayurveda) in our entire body to kick start our metabolism and wake us up. It is this pitta which makes us hungry because increased metabolism increases energy demand too which we get through food. And it is pitta only which digests the food that we consume. That’s why we don’t feel hungry during dark hours (unless we are surrounded by very strong artificial light). It is also the reason that the Lunch should be heaviest (unlike the old saying of west) when sun is right above our head and pitta is highest in the body demanding heaviest food due to a highest metabolism.
And since during solar eclipse there is a sudden loss of sunlight (extent of loss depends upon the extent of eclipse), pitta in the body too goes down suddenly resulting in sudden drop of metabolism, leading to incomplete digestion of consumed food. And a partially (or incomplete) digested food produces toxins in the body which become the cause of serious diseases. This is the reason that during solar eclipse, one should have light food which is easily digested even with low pitta (for example well cooked moong dal and rice) and absolute fasting may not be required. Remember, the extent of fasting depends upon the duration and the extent of eclipse (partial or complete). Longer and more (complete) the eclipse, more would be the fasting required. Also remember that summer fruits being cold in nature should not be consumed during solar eclipse because they need pitta to get digested. Of course, there is one more factor which plays role in this and that is the constitution (from ayurvedic standpoint) of the person (to understand your constitution click the video below.
And now let’s discuss about the lunar eclipse. We all know that it’s the combination of moon’s and sun’s gravity (though primarily moon’s, being very close to earth) which pull water of the oceans on earth and cause high and low tides. And since our body too has around 70% water, these heavenly bodies exert their pull on this water too. So on full moon, body fluids especially blood also get pulled towards upper part of the body thereby reducing it towards lower body parts. Also, the light of full moon is very relaxing and cool which reduces pitta (heat or current in the body) which is the reason meditation during full moon is considered very relaxing for mind. However during lunar eclipse which always happens on full moon only, there is a sudden downward pull of blood due to opposite pull from the sun which is aligned on the other side of earth along with sudden disappearance of white light. Both these phenomenon during lunar eclipse, create confusion in the metabolism of the human body and therefore it is advised to avoid consuming food during and around 4 hrs before this phenomenon (since grains etc take around 4 hrs to get digested however fruits and water can be consumed as they get immediately digested in the body).