Objectives To evaluate the validity of food behavior items, using a biological measure (serum carotenoids) as the criterion for validity of fruit and vegetable intake, and the results from multiple 24-hour recalls to test convergent validity with nutrient intake.
The FFQ is a commonly used dietary assessment tool in epidemiologic studies because it is feasible to use in large studies and accurately rank-orders individuals across the spectra of foods and nutrients; however, the validity of estimates varies across nutrients and populations.
Regarding the validity of the estimates of nutrients consumed for the food-frequency information assessed in this study, both antioxidant [ 26] and phytoestrogen (Horn-Ross, P. et al., Am J Epidemiol, in review, 2005) nutrients estimates closely approximate reference values in previous studies.
The Anti Cancer Council of Victoria FFQ: relative validity of nutrient intakes compared with weighed food records in young to middle-aged women in a study of iron supplementation.
In the absence of detailed data on nutrient absorption levels, the validity of the questionnaire response on fish-dinner frequency cannot be determined.
The validity of biochemical indicators is vulnerable to the problems of nutrient homeostatic mechanisms, bioavailability, time integration, medical condition, genetic backgrounds, and types of analytic procedures [ 11].
The validity of ranking the energy-adjusted intakes of many nutrients has been studied previously in an adult Japanese population (19).
The validity of the questionnaire has been examined for estimating dietary fibre intake, but not for other nutrients (Gear et al, 1979).
The validity of the mathematical model is verified by a computational fluid dynamics (CFD) analysis on the flow and nutrient transport of the DOW plume.
