Why do most people believe that you have to eat meat to get protein and that you have to drink milk to get calcium?

Schools rely on textbooks and curricula approved by state and local boards of education. Most of these are based on the Dietary Guidelines for Americans and written by Registered Dietitians (RDs). Unfortunately, both the Dietary Guidelines and the credentialing programs for RDs are heavily influenced by the industries that profit from food. In some cases, the industries themselves write the curricula and provide it free to teachers, as is the case with the Dairy Council of California, the largest dairy-producing state in the country, which provides free lesson plans to teachers who taught 6.7 million K-12 students in 2008, or nearly 18% of the students in the United States.