Grains must be avoided on Ekadashi as they have a detrimental effect on our body. On Ekadashi with regards to the Moon, the Moon plays havoc on our body. During this time on Earth we have catastrophes like Typhoons, Tidal Waves, Tsunamis and so forth. So the water in the sea and so many other things are severely effected by the position of the moon. There was also a research done in hospitals to find out when most patients died and they found out that it happens within the 5 days of Ekadashi. The reason for this is that the foodstuff they ate retains the water and since the moon plays such havoc with water, it effects our health adversely. Of course the sure way is to fast completely.Water of course can be taken. Except if you wish to do Nirjala (without water) Fast. Do not use any cooking ingredients that might be mixed with grains, such as ghee that has been used to fry puris, or spices touched by hands dusted with flour. There is absolutely NO doubt about what is NOT permissible to eat on Ekadashi… ANNA (grains). However it is how you translate this word that makes the difference. Srila Prabhupada, founder Acharya of ISKCON said “Fruits, Roots, Nuts, Milk”. If you stick to these types of foods you should be fine.