Final answer:
The phrase 'For example' helps identify the sentence as a supporting detail by illustrating the types of foods that can be consumed in space.
Step-by-step explanation:
The phrase 'For example' from the sentence most helps the reader to identify it as a supporting detail. This phrase introduces an instance or case that is intended to illustrate a statement or to show how it is applied in practice. In this context, it is being used to give a specific example of the types of foods that can be eaten in space, supporting the broader discussion on zero-gravity nutrition.
Examples are commonly employed in writing to clarify and support statements made by an author, which is essential in texts that aim to inform or explain a topic to readers.