Fasting and punishing the body is not a path for our generation. Today, we must lift the body up, rather than beat it down.
Not only because most of us are too fragile to weaken our bodies any more. Not only because the faintness of hunger can interfere with your ability to do good in the world.
But principally because now has come the time to reveal the divine within our own sinews of flesh and blood.
And to do that, you must work with the body, according to its needs.

With the body In my younger years, I attempted to fast during Yom Kippur ... I'm a juvenile diabetic and have to have food. In youthful exuberance, I thought I would be okay IF I ate right before midnight. HAH! I lasted until 14:30 and passed out in shul - a fact that scared everyone! As a result, and with years of practice, have reached the point of knowing the bare minimum that will allow me to function, not harm my body, while still depriving me ... I like coffee, so don't indulge; I also avoid "pleasurable foods" - food that I enjoy eating. Yes, I know it is not completely kosher, but I also took several lectures about taking actions that harm me.