Actually, the phrase "may you have an easy and meaningful fast" is a pretty standard Yom Kippur wish. Fasting serves several purposes. One is to take our attention away from the physical and focus on the spiritual. Another is to be more like angels, who don't need food or water. Another is deprivation or sacrifice -- which is what I think you're referring to -- but that doesn't mean suffering. We're asked to deprive ourselves of food and water, which, of course, is a sacrifice -- but undue suffering takes one's attention away from the spiritual and focuses back on the source of suffering itself, so that's not really the point. But that's why we wish people a fast that's both easy and meaningful -- not so hard that the fasting takes away focus, but also not *so* easy that it's not noticeable.