NO. 10 (TIE): JENNY CRAIG DIET
Known for its celebrity spokespeople, including Kirstie Alley and Mariah Carey, the Jenny Craig diet uses weight-control counseling and prepared meals that can either be delivered or picked up at a Jenny Craig location.
NO. 8 (TIE): VOLUMETRICS DIET
Volumetrics is a diet developed by Penn State University nutrition professor Barbara Rolls. It categorizes foods based on density, with less dense foods — like soups or vegetables high in water — preferred over pizza, cookies, and butter.