What the Experts Say About the Grapefruit Diet?

"Any diet that's this low in calories and cuts otherwise healthy foods is extremely unhealthy and should be avoided," says Dawn Jackson Blatner, R.D., L.D., national media spokesperson for the American Dietetic Association and a registered dietitian with the Northwestern Memorial Wellness Institute in Chicago. Blatner also can't say that grapefruit is truly the magical component here, for any time your caloric intake drops this low, you will lose weight. "Yet as soon as you return to regular eating, you'll gain it all back -- and then some," she adds.