The South Beach Diet is a popular fad diet developed by Arthur Agatston and promoted in a best-selling 2003 book.[1][2][3]  It emphasizes eating high-fiber, low-glycemic carbohydrates, unsaturated fats, and lean protein, and categorizes carbohydrates and fats as "good" or "bad".[4] Like other fad diets,[5] it may have elements which are generally recognized as sensible, but it promises benefits not backed by supporting evidence or sound science.[1][6]