Stanford University released a study last week of more than 300 women who were placed on one of four popular diets for one year to see which was the most effective. The low-carb Atkins diet was the victor ... sort of. Study author Christopher Gardner said it's likely because the Atkins diet is easy to understand, it encourages drinking water, and is a high-protein diet. But it wasn't all good news for Atkins followers. The group on the diet gained back more weight than the other women.