Final answer:
Celebrity endorsements on a nutrition website may indicate unreliability, unlike evidence-based references, professional approval, and affiliation with recognized organizations which contribute to the site's trustworthiness.
Step-by-step explanation:
Regarding the question of which element indicates that a nutrition website may NOT be a reliable source of information, the answer is: b) Celebrity endorsements. While celebrities often have wide reach and influence, their endorsements are frequently paid and they may not possess the scientific background to evaluate the nutritional information accurately. In contrast, references to scientific studies, nutritionist-approved content, and updated information from reputable organizations like the National Academy of Sciences and the Food and Nutrition Information Center, bolster a website's credibility. Always assess the website's reliability by checking for affiliation with credible institutions, author credentials, cited sources, and avoiding biases or undue influence by advertisements.