Differences between Food Group Reports of Low-Energy Reporters and Non-Low-Energy Reporters on a Food Frequency Questionnaire

Background: Low-energy reporters (LERs) and non-LERs differ with respect to several characteristics, including self-reported intake of foods. Limited data exist regarding food intake difference between LERs and non-LERs identified using doubly labeled water (DLW). Objective: In the Observing Protein and Energy Nutrition Study (September 1999-March 2000), differences were examined between food group reports of LERs and non-LERs on a food frequency questionnaire (FFQ) (n=440). Design: LERs were identified using DLW. Responses of LERs (n=220) and non-LERs (n=220) for 43 food groups on the FFQ were examined in three ways: whether they reported consuming a food group (yes/no), how frequently they reported consuming it (times per day), and the reported portion size (small, medium, or large). Analyses were adjusted for total energy expenditure from DLW. Results: LERs, compared to non-LERs, were less likely to report consumption for one food group among women (soft drinks/regular). Among men, there was no difference between LERs and non-LERs with respect to reporting consumption of food groups. Reported mean daily frequency of consumption was lower among LERs compared with non-LERs for 23 food groups among women and 24 food groups among men (18 food groups were similar in men and women). In addition, reported mean portion sizes were smaller for LERs compared with non-LERs for six food groups among women and five food groups among men (three food groups were similar in men and women). Results varied minimally by sex and body mass index. Conclusions: LERs, compared with non-LERs, were more likely to differ regarding their reported frequency of consumption of food groups than their reported consumption (yes/no) or portion size of food groups. Results did not vary greatly by sex or body mass index. It still remains unclear whether improvement in questionnaire design or additional tools or methods would lead to a decrease in differential reporting due to LER status on an FFQ.