Experience of dietary assessment and validation from three Swedish studies in the elderly

Background/Objectives: The elderly are a growing part of the population. The objectives have been to describe the dietary assessment methods undertaken, and to evaluate the different validation methods and their performance in free-living elderly populations. Subjects/Methods: Participants were from three studies, the Johanneberg, H70 and Nordic Research on Ageing ( NORA) studies undertaken in Sweden. The mean age across these studies ranged from 70 to 80 years, and cohort size ranged from n = 173 to a total of 1360 in the four cohorts of the H70 geriatric population study. A food frequency questionnaire (FFQ) was used in Johanneberg and a diet history (DH) in H70 and NORA. Validation was undertaken using a 4-day food record (FR), four 24-h urinary nitrogen (UN) collections and energy intake/basal metabolic rate (EI/BMR) cutoffs in Johanneberg, EI/BMR cutoffs, total energy expenditure (TEE) estimated by heart rate monitoring, activity diary and doubly labelled water in H70, and EI/BMR cutoffs in NORA. Results: The FFQ provided higher intakes of EI and nutrients vs FR, confirmed by UN for protein. Compared with EI/BMR cutoffs, overestimation of EI was moderate. DH showed that slight underestimation vs heart rate was in accordance with activity diary, but compared with doubly labelled water, DH underestimated EI by 12%. In NORA, EI/BMR was high compared with EI/BMR cutoffs. Validation methods detected under-and over-reporting. EI and nutrient intake were in accordance with recommendations. Conclusions: Elderly up to their 80s can perform well in dietary studies. However, people over the age of 80 years may tend to report food habits from earlier in life.