Fiber has never been what you’d call a sexy nutrient. But suddenly, it’s a superstar: Manufacturers are adding it to yogurt, juice, even artificial sweetener. There’s no question about the health benefits of the naturally occurring stuff: It’s known to lower the risk of heart disease and diabetes, and it helps prevent weight gain while cutting the risks of some cancers. Foods with added fiber, however, use a form that’s been stripped out of the foods that originally contained it. These “isolated” fibers are flavorless and don’t turn juice and yogurt into gummy, grainy glop. That’s the good news. The bad news is that there’s no evidence they protect against chronic disease. So go ahead and try a glass of fiber-boosted grape juice. Just don’t forget to also eat more whole grains, beans, fruits, and veggies.