More information about your study design would be needed to determine the correct measure, but here are some starting points:

The 6-item short scale from USDA's Food Security Survey Module: http://www.ers.usda.gov/topics/food-nutrition-assistance/food-security-in-the-us/measurement.aspx (click on the survey tools link on the page).

direct link to pdf: http://www.ers.usda.gov/datafiles/Food_Security_in_the_United_States/Food_Security_Survey_Modules/short2012.pdf

You can turn this into a 5-question scale by modifying the answer options with two of the questions (there is a skip pattern).

In this module, there also is a "screener" option that allows for skipping the last 2-3 questions depending on the answers to the first 3 questions.

Pros and cons of various survey modules are also available through the USDA's "measurement" page and will be helpful for you to pick the right one for your study.

If food sufficiency will be an adequate measure for your study, you can find the food sufficiency screeners on the same USDA link above.

If the study will be done in a hospital setting, you may also want to check out this 2-question version published by E Hager, John Cook, Mariana Chilton and others:

http://pediatrics.aappublications.org/content/126/1/e26.short

Thanks Nurgul so much for pointing me in the right direction! I now have a more specific question. I'm planning to use the adult set of questions longitudinally to monitor food insecurity over time using the "last 30 days" referent period. I'm hoping to pilot them in person at a community setting and/or via a phone survey. Do you know how well these items perform in terms of looking at changes over time? Or is there evidence of testing effects resulting from repeated surveys?  Do you have any thoughts or additional references you can point me to in terms of finding some answers to these questions.

We have used the same module at the Interdisciplinary Center for Food Security for our longitudinal study of Missouri food pantry users and it has thus far responded well to changes in the demographic composition, income, shocks (i.e. the recession), etc. We are currently working on a paper that looks at a component of this, but I have yet to run across any longitudinal studies that use this specific measure. I would check the environmental nutrition literature--they use this measure extensively.  Hope this helps!