General Documentation

A semi-quantitative food frequency questionnaire (FFQ) has been developed at Harvard University and is available for research purposes. It is the result of over forty years of continued development, evaluation, refinement, and re-evaluation. It was originally created to be used as a paper self-administered, mailed questionnaire. At every step we have attempted to examine the reproducibility and validity of the questionnaire by comparing its estimates with those of diet records or multiple 24-hour recalls and with relevant biochemical indicators of nutrient intakes.  Such studies have been conducted among adults of all ages and both sexes, and among a variety of socioeconomic groups; many of these validation studies have been published. The results of the validation studies have indicated that the method is remarkably robust; similarly valid results have been obtained from virtually all the groups that we have studied. Obviously, the process of continued refinement of the questionnaire can not stop, in part because the nature of the food supply and the distribution of dietary intakes is in constant change.

While the semi-quantitative FFQ was developed for our own research purposes, we are happy to share it with other investigators. This extended use has obvious advantages in better defining the useful scope and limits of the methodology, and, sometimes, providing direct information on the degree of validity in different populations and with various methods of administration.

Although we are not organized as a service group, we have tried to accommodate the wide variety of requests from different investigators as efficiently as possible and within the limited constraints of research budgets. For routine questionnaire processing, this operates quite smoothly at present. Most importantly, we have strived to maintain the same level of data quality for external users, as we want for our own research. It is our hope to be able to provide a REDCAP questionnaire soon for investigators preferring to use an online questionnaire in their study. Details will be forthcoming.

We have developed this website for those interested in obtaining copies of the food frequency questionnaires. Due to the volume of investigators interested in receiving the questionnaires, we ask you to please review the information on this website to answer general questions. PLEASE NOTE: ANY SALE OR COMMERCIAL USE OF THE QUESTIONNAIRE REQUIRES WRITTEN PERMISSION OF OUR INSTITUTION.


Frequently Asked Questions

Completing the FFQs

Mailing and payment

WinZip files and access

Calculating servings

Self-coders and/or editors

Validation articles and nutrient database reference