Dietary fat intake from fish and dairyproducts in adolescents assessed by the webbased dietary assessment method Riksmaten Flex : a pilot validation

Background: Milk and dairy products are common compounds of the Swedish diet. Fish, in particular oily fish, is recommended for health effects. Accurate dietary information on individuals diet is of great importance when studying the associations between diet and health. The National Food Agency in Sweden has developed a new web-based method, Riksmaten Flex (RF), for assessing food intake in adolescents. Objective: To investigate how well the web-based method Riksmaten Flex (RF) captures intake of fish and dairy products compared to 24-hour recalls. Serum concentrations of fatty acids, biomarkers for fish and dairy products, were used to investigate the reported intake of fish and dairy products from each respective method. Method: Participants in the age of 11-12, 14-15 and 17-18 years old were recruited from different schools in Sweden. The adolescents completed two days of dietary recordings in RF and two 24-hour recalls. Blood samples were taken and analyzed. Results: More girls than boys completed the study and the reported median energy intake was higher in RF compared to 24-hour recalls (p=0,005). Intake of dairy products correlated with the reported RF and 24-hour recalls. Intake of dairy products correlated significantly with pentadecanoic acid (15:0) in serum cholesterol esters and phospholipids and with heptadecaoic acid (17:0) in serum phospholipids. There was no significant correlation between fatty acids and the reported fish intake from 24-hour recalls but however for fish intake from RF and eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and total n-3 fatty acids. Conclusion: It is concluded that weak correlations were found between the reported intake in RF, 24-hour recalls and biomarkers for fatty acids in blood. Significance of the correlations cannot be concluded due to the lack of a sample size calculation. Small number of participants, few days of registration and a large drop-out rate are some of the limitations