Hold whomever you like responsible—Gwyneth, maybe Gisele—but clean eating is one trend that's here to stay. The basic tenets? Consume whole, organic foods (namely produce and lean meats) while cutting back on (and ideally, eliminating) caffeine, processed sugar, alcohol, gluten, and dairy. "Removing these toxic triggers from your diet can make a hugely positive impact on your health," says Alejandro Junger, M.D., author of the new book Clean Eats. "Most people have more energy as a result, and some have even overcome issues like chronic headaches and seasonal allergies."