Nutrition and Dietetics

Search Strategy

Search Strategy: A search strategy is an organized structure of key terms used to search a database. PICO(T) is part of your search strategy. The search strategy combines the key concepts of your search questions in order to retrieve accurate results. NYU LibGuide  provides students with a thorough overview of the Search Strategy. This LibGuide includes Boolean worksheets.

Researchers use Boolean Logic to combine search terms. 

Most databases allow the use of AND, OR and NOT to broaden or narrow and search. 

  • AND will narrow the search to include only records with both terms. 
  • OR with broaden the search to include records with either term.
  • NOT will narrow the search to exclude records with one of the terms.

Truncation:  You can use an * at the end of a word stem to broaden your search to include related terms.  For example, to search for child, children or childhood use the search term child*

Putting quotes "" around words allows you to search for a phrase.  For example, searching language development, without quotes, finds records with both the word 'language' and 'development' somewhere in the record.  Searching "language development", with quotes, only find records with the phrase "language development".

Here is a sample search that uses the quotation marks to keep the words overweight and adults next to one another; hence only articles with those terms side-by-side will show up in the result list. Furthermore, this search will only pull up articles with the terms dietary and supplements next to one another.  


Sample search using quotation marks


Limiters: Use limiters to hone in on topics. Health/Nursing databases provide many limiters. CINAHL's limiters enables you to limit by peer-reviewed, geography, age, sex, human study, evidence based practice, etc.

Screencast of CINAHL's limiters


The PICO(T) question is the catalyst to your research:

1. PICOT Question:

How effective is the consumption of low glycemic index foods for reducing energy intake and promoting weight loss in adults?


Screen shot of PICOT Question in an Advanced Cinahl database search



Subject Searching

Subject searching is a more precise way to search, particularly when your search term can have more than one meaning. Every item in a database is assigned specific subject headings using a controlled vocabulary, which can vary by database. Most medical databases use MeSH (Medical Subject Headings), which is continually updated by the National Library of Medicine. MeSH uses a hierarchical system that allows for easy broadening or narrowing of topics. CINAHL uses subject headings unique to the database that use the same structure. 

MESH Subject Headings- ​

MeSH is the National Library of Medicine's controlled vocabulary thesaurus. It consists of sets of terms naming descriptors in a hierarchical  structure that permits searching at various levels of specificity.

MeSH descriptors are arranged in both an alphabetic and a hierarchical structure. At the most general level of the hierarchical structure are very broad headings such as "Anatomy" or "Mental Disorders." More specific headings are found at more narrow levels of the thirteen-level hierarchy, such as "Ankle" and "Conduct Disorder." There are over 28,000 descriptors in MeSH with over 90,000 entry terms that assist in finding the most appropriate MeSH Heading, for example, "Vitamin C" is an entry term to "Ascorbic Acid." In addition to these headings, there are more than 240,000 Supplementary Concept Records (SCRs) within a separate file. Generally SCR records contain specific examples of chemicals, diseases, and drug protocols. They are updated more frequently than descriptors. Each SCR is assigned to a related descriptor via the Heading Map (HM) field. The HM is used to rapidly identify the most specific descriptor class and include it in the citation.

CINAHL Subject Headings-

The CINAHL subject headings are based on the MeSH headings, with additional specific nursing and allied health headings added as appropriate. Each year, the headings are updated and revised relative to terminology needed in these fields. In addition, new terms from MeSH may be added as well.



Watch: Use MeSH to Build a Better PubMed Query


Credits: National Center for Biotechnology Information (NCBI)


Your instructor will often request that you track your search terms.  Many databases offer a "Search History" option.  

You can also save your searches within CINAHL and PubMed. In CINAHL, you have the option to create a My EBSCOhost folder; In PubMed you can save your searches within a NCBI account.  Other  databases offer similar options.