Dietary assessment in food environment research: a systematic review

Context: The existing evidence on food environments and diet is inconsistent, potentially because of heterogeneity in measures used to assess diet. The objective of this review, conducted in 2012-2013, was to examine measures of dietary intake utilized in food environment research.

Evidence acquisition: Included studies were published from January 2007 through June 2012 and assessed relationships between at least one food environment exposure and at least one dietary outcome. Fifty-one articles were identified using PubMed, SCOPUS, Web of Knowledge, and PsycINFO; references listed in the papers reviewed and relevant review articles; and the National Cancer Institute's Measures of the Food Environment website. The frequency of the use of dietary intake measures and assessment of specific dietary outcomes were examined, as were patterns of results among studies using different dietary measures.

Evidence synthesis: The majority of studies used brief instruments, such as screeners or one or two questions, to assess intake. Food frequency questionnaires were used in about a quarter of studies, one in ten used 24-hour recalls, and fewer than one in 20 used diaries. Little consideration of dietary measurement error was evident. Associations between the food environment and diet were more consistently in the expected direction in studies using less error-prone measures.

Conclusions: There is a tendency toward the use of brief dietary assessment instruments with low cost and burden rather than more detailed instruments that capture intake with less bias. Use of error-prone dietary measures may lead to spurious findings and reduced power to detect associations.