My mother used to keep fasts on holy 11th day of the moon calender called Ekadashi.
We waited as c hildren that she will make her special meal for fasting day. It consisted of Kutu ka atta a sort of coarse grain with low calorific value. Besides this she will also use flour from Trapa bispinosa. A plant growing in ponds and its fruits had two spines which gave it the name of T. bispinosa.
Stragely enough on my recent visit to Germany a saw the flour of the Trapa bispinosa being sold for some euro ( in India would be some rupees) in nicely packed bottle in reform house or natural food house.
It was supposed to be helpful in controlling menstrual disorders in women.
I still wonder how the old hindu fasting women ( fasts are generally done by hindu women for welfare of their family) knew to take flour from Trapa bispinosa .  Perhaps no body knew this that science will findout potential uses of this plant as medicine also.
Coarse grains are essential for human body as they have different complex of amino acids and starch etc Taking different mixture of food grains is healthy and nutritious.
May be our old mothers and grand mothers had some knowledge to share in every religion which now has some scientific footings.
May be you have something to offer.