Final answer:
The article's central idea is the confusion surrounding healthy eating, influenced by individual needs and various external factors, including social and cultural aspects.
Step-by-step explanation:
The central idea of the Newsela article is that there is confusion about what constitutes a healthy diet due to the varying nutritional needs of individuals and the influences from different sources. This confusion exists among a wide range of people including the affluent and the impoverished. Two details that support this central idea are that each person's body is unique; therefore, their nutritional needs differ, and that cultural and social factors influence what different people eat, which can impact their nutritional choices. Furthermore, the mention of how difficult it can be to choose healthy options when faced with advertising and the convenience of fast food reinforces the central theme of confusion regarding healthy eating.