Earlier this week there was an interesting discussion on Raw Food Rehab about juice feasting. A rehabber was concerned that her feast would result in a slowed metabolism and extra weight gain once it was over. If you're primarily doing a feast for weight loss, nothing is scarier than the idea of regaining all those pounds you saw melt away.
Matt Monarch has a clear explanation of how juice feasting resets the metabolism in this article. The bottom line, from his perspective, is that it can slow the metabolism, and that's a good thing because it means your body can run more efficiently, requiring less food, though this is a reality some people aren't prepared to handle. He recommends intense exercise as a means to kick start the metabolism. He also suggests that as we come out on the other side of a feast, we expect to consume fewer calories than we did before juice feasting.
As a culture, the goal has been to figure out how to consume more calories without increasing our waist size. (Loosening your belt under the table is acceptable though!) It challenges our thinking to consider purposely reseting the body to need less food to function optimally.
It's clear our bodies can be easily reset to require less food. The more important thing is to reset our minds and emotions to go along with the program.