please don't feel bad! sure, it is better to tell the truth than to lie, but everything is not black and white... there are HUGE grey areas! and one thing i whole-heartedly believe is that it is absolutely okay, even necessary to lie if it is in order to protect yourself or someone else from harm!
i don't know how YOUR parents would react to the truth, but i can guarantee you that if my mother ever found out that i was fasting, she would surely contact my psychiatrist and he'd have me forcibly admitted to the hospital and prescribe me anti-psychotics. so i can tell you, without a doubt, i would have done and said exactly the same thing to my parents if i were in your shoes. (though, even just telling my parents that i was skipping one meal a day would cause them alarm!)
a very good friend of mine gave me some terrific advice: DO NOT CAST YOUR PEARLS TO SWINE. we on this forum are a minority... we understand the truth to healing... we see through the "standard american diet" and we know that current medical practices merely "cover-up" the underlying source of the problem. however, most other people are still in the dark and are completely unwilling to see a new point of view. so it is fruitless, even damaging to you to have to engage in discussions/arguments about it with these types of people. you would waste valuable energy trying to defend yourself to someone who will just try to scare you and make you bad, and quite possibly make you doubt yourself enough to quit!
so good for you for protecting yourself and doing the best that you could under the circumstances to allow your fast to progress as smoothly as possible!
p.s. do you mind if i ask if you are a single mom? i am :)