This report reviews data collected by Commission staff on the types of claims made in 11,647 advertisements taken from a sample of eight leading magazines between 1977 and 1997. The primary focus of the study is on advertising claims related to health and nutrition, but it also examines other types of advertising claims. The report further reviews how nutrition-related claims in advertising changed under the various regulatory policies in place during these years. It is revealed that nutrition-related claims were a major focus of food advertising and an important focus of competition during the two-decade period covered by the report. Moreover, data indicate a sustained movement toward specific nutrient claims, such as "low fat," in place of, or in addition, to more general nutrition claims, such as "nutritious." The study finds that changes in advertising content appear to be associated with changes in regulatory rules and enforcement policies.