"You're going to be drinking something every 90 minutes to two hours, so you won't feel deprived or hungry," Page tells WebMD. "As your body gets lighter and lighter through the weekend, you can feel what's going on. You're getting rid of toxins accumulated during the winter. Your body is starting to release fat, those extra pounds." If you feel "congested" from too much food -- or the wrong kinds of food -- you may want to detoxify, she says. If your energy level is low, if you have been taking many medications that have not been eliminated from your system, a weekend detox may help you feel better. Additionally, no fruit is off-limits once you've completed the 31 days. "You can have a sandwich in week four, which just makes things easier," Alpert said. Week four is the home stretch, when you can enjoy two starches per day, including bread and rice, in addition to high-fiber crackers.