The principle behind fasting is that God never takes food, and by fasting we get nearness to God and thereby absorb his condition to some extent. But it fits well with the humility of a devotee to take a little food, thus admitting that we cannot live without food, like Him. When fasting without even taking water, we boost our ego.
Taken from the book "Complete Works of Ram Chandra, Vol. 4 (1st edn., 2014)", Chapter "Pearls of Wisdom", pg. 264, by Babuji Maharaj
One would never have thought of the principle of Fasting from this perspective, that God never takes food and so to get nearness to Him, we also try to follow that. But then in Sahaj Marg, Babuji Maharaj goes further to explain that extreme demonstration of Fasting is just a boosting our ego and really not beneficial to the spiritual path. If we really put our heads down and think about it, this is really true, that very much like one demonstrates his strength by building his muscles on one extreme which is nothing but a display of ego, that I did it, on this other extreme, complete fasting is also a display of ego that I can do this, and nothing else. If I may extend this, complete abstinence of any type is a display of ego. A display of the fact that I can do it, either just for myself, or for the world to see, or for God to see, it does not matter.
Sahaj Marg practice talks about holding onto a higher principle with all you got, so that all these petty things including all manifestations of the lower-self drops off automatically, and we are focused on one thing and one thing only, which is our goal, which is our ideal, which is what we want to become, which is not what I am now. This way, Sahaj Marg can be seen as a middle-path, with complete moderation, no excesses of any type, on either side as in complete excess on one side and complete negation on the other side. All the Masters of Sahaj Marg have lived this life of complete moderation to its fullest degree. Babuji Maharaj demonstrated simplicity and moderation in his whole life. Chariji Maharaj demonstrated what it means to work and leave the results to Him alone, and now Shri. Kamlesh D Patel, the current Master and Spiritual representative of his lineage of Gurus and the President of Shri Ram Chandra Mission, has his complete focus on Heartfulness, a simple approach to offering Sahaj Marg meditation practice to people of all walks of life all over the world.