Final answer:
Media is an external influence that can affect food choices by shaping perceptions, providing information about various foods, and creating social pressures to eat in certain ways.
Step-by-step explanation:
An external influence that could affect food choices is media. Unlike factors such as genetics, taste, and emotions which are intrinsic, media influence is external and powerful in shaping food preferences and choices. The representation of food in television, movies, advertisements, and social media can significantly impact what and how we eat. For example, seeing commercials for certain fast food restaurants might increase cravings for those foods, or food trends promoted by celebrities on social media can lead to changes in eating habits.
Media is part of the globalization of food, where food choices are influenced by marketing strategies and cultural messaging. Popularity of certain diets or foods on social media platforms may also lead individuals to adopt similar eating patterns. Furthermore, media can impact public opinion and perceptions about what foods are desirable or socially acceptable, similarly to how demographic groups can influence opinions on other issues, as noted by Walter Lippmann in 'Public Opinion'.
Thus, media serves as one of the many factors affecting what we eat, alongside others such as culture and family, availability and cost, and education. It plays a role in shaping dietary choices by influencing perceptions, providing information, and sometimes by creating peer pressure to eat certain ways or try new foods.