Cynthia sass, mph, rd, is a registered dietitian, the sports nutrition consultant to the new york rangers and new york yankees, and the nutritionist behind and coauthor of flat belly diet. Flat belly diet 9781594868511 by sass, cynthia and a great selection of similar new, used and collectible books available now at great prices. Cynthia consulted for the new york yankees major league team for five seasons 20152019. Cynthia is a three time new york times best selling author, columnist and practitioner, with masters degrees in both nutrition science and public health. The first part is a 5 day quick start program in which you eat only 5 foods in specific combinations. See all books authored by cynthia sass, including prevention flat belly diet, and flat belly diet. Cynthia sass, mph, rd, is a registered dietitian, the nutrition consultant to the tampa bay rays, and the nutritionist behind and coauthor of the new york times bestseller flat belly diet.