Day 2: Replace every beverage with water.
Yes, that means no energy drinks, no margaritas, no diet sodas, no beer. We'll give you one cup of coffee or tea in the morning (skip the sugar), but every other drink from here on out should be plain old H2O. “Drinking plenty of water improves how your cells function, muscles contract, and brain thinks,” says nutritionist Ryan D. Andrews, a coach with Precision Nutrition. “Drinking anything high in sugar like juice, energy drinks, and flavored coffee drinks floods the liver with sugar, and the spillover is fat.”