Final answer:
The Canadian Children's Food and Beverage Advertising Initiative (CAI) exists due to concerns about childhood obesity and regulations for healthier food choices. The ban on junk food in schools is part of the initiative.
Step-by-step explanation:
The Canadian Children's Food and Beverage Advertising Initiative (CAI) exists due to the socio-cultural trend of rising concerns about childhood obesity and attendant diseases. With the increasing presence of advertising in various platforms such as television, movies, public transportation, and schools, there is a need to regulate and promote healthier food choices for children. The ban on junk food in schools, initiated by the United States Department of Agriculture's Healthy, Hunger Free Kids Act and Michelle Obama's Let's Move! Initiative, also contributes to the existence of the CAI.