What is The Fast Metabolism Diet, exactly?

In a nutshell, The Fast Metabolism Diet is a 28-day plan that cycles through three multi-day phases each week and claims to help rev your metabolism through macronutrient cycling—rotating periods of high-protein, high-carb, and high-fat eating within each week.

The Fast Metabolism Diet: Eat More Food and Lose More Weight

The diet restricts corn, dairy, soy, refined sugar, caffeine, alcohol, dried fruit, fruit juice, wheat (except sprouted or natural yeast wheat), and nitrates (found in processed meats) for all 28 days.

You're instructed to eat five times per day—within 30 minutes of waking, and every three to four hours while awake. And you need to drink at least half of your bodyweight in ounces of water every day—so a 120-pound woman would need to drink 60 ounces of water. There are also supplements available for purchase for “maximum metabolism impact," which can be taken during the 28 days and after.

Beyond that, there are three separate phases you cycle through each week. The idea is that each phase focuses on different macronutrients.