Dietary Methodology: Advancements in the Development of Short Instruments to Assess Dietary Fat

Abstract

Short instruments for assessing diet have practical utility if they meet acceptable standards of reliability and validity for the population groups with which they are used. The science of dietary assessment has advanced over the past 20 years, yet the complex nature of what people eat—coupled with our improved understanding of the factors that contribute to dietary intake and behaviors—continues to pose challenges in the development and utility of short dietary instruments, such as short forms, screeners, and other brief methods of assessing diet. This issue of the Journal includes three studies that use different short instruments to assess dietary fat intake (as a percentage of calories) and compare estimates with those derived from other dietary assessment methods. The first study, by Thompson and colleagues ( 1 Thompson F.E. Midthune D. Subar A.F. Kipnis V. Kahle L.L. Schatzkin A. Development and evaluation of a short instrument to estimate usual dietary intake of percentage energy from fat. J Am Diet Assoc. 2007; 107: 760-767 Google Scholar ), compares a 13-item fat screener with a 120-item food frequency questionnaire (FFQ) and usual (or “true”) fat intake estimated by using two 24-hour recalls in 404 adult men and women enrolled in the National Institutes of Health-AARP Diet and Health Study. The second and third studies focus on assessing fat intake among African Americans. Teal and colleagues ( 2 Teal C.R. Baham D.L. Gor B.J. Jones L.A. Is the MEDFICTS rapid dietary fat screener valid for pre-menopausal African-American women?. J Am Diet Assoc. 2007; 107: 773-781 Google Scholar ) compare an existing instrument, MEDFICTS—or meats, eggs, dairy, fried foods, fat in baked goods, convenience foods, fat added at the table, and snacks—with the Arizona Food Frequency Questionnaire (Arizona FFQ), a modified Block FFQ in 184 premenopausal African-American women. Satia and Galanko ( 3 Satia J.A. Galanko J.A. Comparison of three methods of measuring dietary fat consumption by African-American adults. J Am Diet Assoc. 2007; 107: 782-791 Google Scholar ) compare three methods—a household food inventory, a fat-related diet habits questionnaire, and a fat screener—in 658 African-American men and women living in North Carolina. R. R. Briefel is a Senior Fellow at Mathematica Policy Research, Inc, Washington, DC.