I've known folks who treat it that way. Some people fast at the drop of a hat. Or they fast for longer than the "recommended" period (the general guidance is to skip two meals; others define it as no food or liquid for a 24-hour period). Perhaps they're taking Jesus' 40-day wilderness fast as their goal--not taking into account symbolic numbers, Middle Eastern traditions of fasting, and the availability of juice from desert plants. These folks are probably messing up their systems and avoiding issues in their family of origin or something.
Speaking of Jesus' wilderness experience, Mormons don't, as a whole, celebrate Lent. While the rest of Christianity has 40 days of service and sacrifice every spring, Mormons try to bring the same attitudes to their monthly fast. Congregations fast and then turn a Sunday meeting (usually the first Sunday of the month) over to sharing spiritual insights and acknowledging God's work in their lives. Individuals can fast for special occasions or concerns as often as the Spirit moves them, to borrow a phrase.
My first attempt at fasting occurred in college. As a committed Christian, I was struggling over concerns about what Mormon missionaries were teaching me and whether there was anything compelling enough about this to suck me out of my then-fully satisfying tradition. I decided to give fasting a try. When I finished my fast, the dining hall was serving the worst meal on campus--meat loaf. Normally, it had the texture and taste of cardboard. It tasted fabulous to me that day. That was a miracle right there. There was another miracle associated with that first fast--an experience that answered none of my intellectual concerns but assured me in bone-marrow deep ways that God wanted me to be a fully committed Christian in the Mormon fold.
Not every fast brings an epiphany, but then neither does every prayer. How fasting works, I haven't a clue. In the ninth chapter of Mark, Christ's disciples are flummoxed when they can't cast out certain "foul spirits." Jesus informs them that "this kind can come forth by nothing, but by prayer and fasting." However fasting works, if Christ says it's got some kind of divine kick to it, that's good enough for me.
My husband once asked a Mormon nutritionist about the physical benefits Latter-day Saints often tout for fasting, such as cleansing the body and giving the system a rest. This man said that the period of time Mormons typically fast puts them into ketosis, where fat starts metabolizing. Things start breaking down. The brain gets a little foggy. According to this guy, there's nothing redeeming about fasting, in a physical sense anyway.
But spiritually, fasting does all sorts of things to people. While your tummy's rumbling, you can get a sense of compassion for people who are always hungry. The "fast offering"--a contribution of the cost of the missed meals--goes to a fund to help the needy. That hungry twinge of empathy becomes service in action.
Fasting also slows you down. In a world where we're constantly bombarded by stimuli and demands, that kind of forced change of pace is valuable. In my experience, the best fasts are ones that intentionally focus on a particular concern--such as so-and-so's troubled pregnancy, a weighty decision, or even as an expression of gratitude.
Yes, fat may be breaking down, but something spiritual may be building up--humility, support, gratitude, generosity, balance, commitment, and consolation.