I do what I call a "liquid fast" on the last day of the month. I eat pureed vegetable soups, juice, protein drinks, water, etc. Basically I am not really limiting my calories any more than any other day, but I'm giving my digestive track a little breather.
And even though I consume the same amount of calories, I usually drop a couple of pounds. Why this is I'm really not sure. I just know that I feel ALOT better doing this even though my diet usually consists of CLEAN food

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And I like the fact that I don't have to worry about what I eat that day. I can still go out with friends to eat, I just have soup or bouillon, liquids are soooo easy! But I only do this once a month like I said before, and it works for me.