What if your search results are not quite what you expected or they seem really off-base? Check Search Details, a box in the lower right of the Search Results page, which shows you how PubMed "translated" your search.
Click on the See more link to discover how PubMed "maps" any term that you enter to MeSH terms when possible & also does a keyword search.
If at least one term for each concept in your search doesn't map to a MeSH term, you should rethink your search terms or contact the library for help.
Look at how some terms were "translated," for example, dietary intake mapped to diet. This is why the search results are so far off topic. We'll need to revise the search.