In 1988 a European multicenter study, named SENECA, was initiated. Nine of the original
19 participating towns in 12 European countries decided to continue the longitudinal
study by conducting a second survey in 1993. The aim of the longitudinal part of the
SENECA study was to provide measurements of diet, lifestyle, health and performance
as such at two points in time and to analyze the direction of changes and possible
interrelationships between the factors studied. For the present paper the experience
with the SENECA study has been used to illustrate the problems related to nutritional
longitudinal studies in different stages of dietary research. In the examples we have
focused on results relating changes in body weight to energy intake and changes in
total cholesterol to intakes of fat and fatty acids of participants from four SENECA
sites. To examine dietary habits a modified dietary history was chosen consisting
of two parts: an estimated record and a checklist of foods. The results demonstrate
that the special design of the study and adaptation of methods made it possible to
deal with several problems encountered in nutritional longitudinal studies in elderly
people. Nevertheless the changes in diet are most likely underestimated. Consequently
in the interpretation of data and further analysis we have to consider this problem
as well as other remaining problems.
Key words
Dietary history - 3-day record - elderly - validity - longitudinal design - cross-cultural
