Comparison of a web-based food record tool and a food-frequency questionnaire and objective validation using the doubly labelled water technique in a Swedish middle-aged population

Two web-based dietary assessment tools have been developed for use in large-scale studies: the Riksmaten method ( 4-d food record) and MiniMeal-Q ( food-frequency method). The aim of the present study was to examine the ability of these methods to capture energy intake against objectively measured total energy expenditure ( TEE) with the doubly labelled water technique ( TEEDLW), and to compare reported energy and macronutrient intake. This study was conducted within the pilot study of the Swedish CArdioPulmonary bioImage Study ( SCAPIS), which included 1111 randomly selected men and women aged 50-64 years from the Gothenburg general population. Of these, 200 were enrolled in the SCAPIS diet substudy. TEEDLW was measured in a subsample ( n 40). Compared with TEEDLW, both methods underestimated energy intake: -2.5 ( SD 2.9) MJ with the Riksmaten method; -2.3 ( SD 3.6) MJ with MiniMeal-Q. Mean reporting accuracy was 80 and 82 %, respectively. The correlation between reported energy intake and TEEDLW was r 0.4 for the Riksmaten method ( P < 0.05) and r 0.28 ( non-significant) for MiniMeal-Q. Women reported similar average intake of energy and macronutrients in both methods whereas men reported higher intakes with the Riksmaten method. Energy-adjusted correlations ranged from 0.14 ( polyunsaturated fat) to 0.77 ( alcohol). Bland-Altman plots showed acceptable agreement for energy and energy-adjusted protein and carbohydrate intake, whereas the agreement for fat intake was poorer. According to energy intake data, both methods displayed similar precision on energy intake reporting. However, MiniMeal-Q was less successful in ranking individuals than the Riksmaten method. The development of methods to achieve limited under-reporting is a major challenge for future research.