As a spiritual discipline, fasting is intended to be just that -- a discipline. Although they didn't articulate it like this, the ancients wisely realized that restricting food and drink was a way to sharpen awareness on many levels. Food fasts, especially rigorous ones, serve to heighten the senses. And because eating is pleasurable, food fasts can indeed induce "suffering."
Lenten fasting is defined as eating only one full meatless meal a day, and two smaller meatless meals that don't add up to another full meal (the Eastern Churches include no alcohol). Never mind that John the Baptist allegedly subsisted on a diet of wild locusts and honey, extreme restriction or deprivation will not necessarily make you holier and may, in fact, make you sick. Starving is not fasting.
Nowhere, either in scripture or church teachings are we asked to fast at the expense of health and well-being. During the fourth century, St. John Chyrsostom wrote, "If your body is not strong enough to continue fasting all day, no wise man will reprove you; for we serve a gentle and merciful Lord who expects nothing of us beyond our strength." The Church, in her wisdom exempts those who are ill, younger than fourteen, or older than ninety-five from fasting. You should also refrain if you've ever been formally diagnosed with an eating disorder, or told you might have one but didn't want to hear it. If this is the case, try fasting from the Internet, daily news reports, or quacking on the phone instead.The Catholic Home by Meredith Gould