מבית הוא מצד מאכלים גסים המפסידים זכות וברירות השכל, עד אשר כח שכלו עובר בעמק עכור ואינו זך לעסוק במושכלות...והמן היה אוכל רוחני כל אוכליו ניצולו מן שני המונעים אלו...הן מבפנים כי היה מאכל זך ונקי מכל פסולת
Internally, this due to the fact that heavy foods detract from the clarity and purity of the intellect, until a person's intellectual ability passes through a valley of fog, lacking the [required] purity to engage in intellectual matters...and the Mon was spiritual food, so that those who ate it were saved from these two detractions...including the internal [detraction] for it was a pure food, clean from all impurities.
Kli Yakkar notes that the Mon's miraculousness emanated not only from its origin and its simple presence each and every day. God also created the Mon as the ideal food for spiritual growth. It didn't give you a sugar high, only to have you fall crashing down to exhaustion in the middle of your first-period Gemara class. It wasn't full of fat and refined grains, leaving you feeling bloated and unable to learn.
It was healthy, tasty, filling and lean, leaving you energized and ready for a long period of spiritual growth.
True, we can't give ourselves or our children Mon for breakfast. But if you wonder why you (or they) are so tired in the middle of the morning, ask yourself this: what did they have for breakfast? If the answer is either (a) Nothing (b) Sugar cereal - or most any breakfast cereal for that matter or (c) snack food - very common among kids - stop wondering.
And start eating - and feeding your children - a healthier, and more spiritually encouraging breakfast.