As a response to recent obesity trends in the United States and other nations, Burger King modified its menu and food preparation practices. In addition to offering lower-fat menu item such as salads, the company has updated its nutrition guides to include dietary guidelines and other nutritional data. One of its reactions to the concerns over trans-fats was to initiate a program in January 2008 to phase out added trans-fat in its products, and to switch to pure vegetable oils that are free of hydrogenated fats. The program ended in early 2009 with a complete changeover to the new oils. Most, but not all, of the products contain no added trans-fats; some products, such as the beef used in the hamburgers, still contain naturally occurring trans-fats.