It is not bad for you. But some of that answer is qualified by your needs on any given day.
I personally did that for over a year. But I was rail thin.
Before I became a vegan which was when I was 33, I was lifting weights and even entered a few novice body building contests. I am only 5'9', but I weighed about 190-ish at the time.
So when I became vegan, I lost a lot of weight, and becuause of that and my previous experience with really carrying to much weight for my frame, i decided to see what the manipulation of weight would have on my body, my blood test levels, and my detox/overall health.
So I did the once a day meal thing.
The best time to eat, if one does that is around noon to 2pm.
The benefits are that you are conserving an amazing amount of energy re digestion. The average American uses about 60% to 70% of available energy to digest their meals, Vegans and raw foodists use around the 20% to 35% range.
That is significant on that the body does not waste that energy. It goes into repair and healing and detox. Speaking of which, on one meal a day, you will detox, assuming your not eating about 2,000 calories at that meal, and that your not eating a lot of animal products and starches and processed and fired foods and the like.
The down side is your going to be very skinny. Thank God I had gotten over my physical insecurities at that point, or I never could have done it. And you may get tired at times.
And socially, there are a lot of ramifications. If one has a active life, with people in it, it is hard to go out to diner and not eat.
But maybe try it for a few days or a week, and see how you feel and if you think you may want to intermittently do it.