Objective: To examine prospective changes in food habits and nutrient intak
es in a representative New Zealand sample of community dwelling adults aged
70 y and over.
Design: Longitudinal study with food intake data collected in 1988/89 and a
gain in 1995/96. In an attempt to distinguish age, time and cohort effects,
data were analysed longitudinally, cross-sectionally and time-sequentially
Subjects: The sample for study consisted of all non-institutionalised peopl
e aged 70 years and over registered with the Mosgiel Health Centre in 1988.
In 1988/89, 678 adults completed a dietary survey (85% of those eligible)
and 248 adults participated again in 1995/96 (66% of those eligible).
Results: Energy intakes declined longitudinally in men only; however, this
decline appeared not to be an aging effect as energy intake was not found t
o decrease with age cross-sectionally. Percentage of energy from protein in
creased by 0.7% in women (95% confidence interval 0.2-1.2) in both the long
itudinal and time-sequential analysis, suggesting a time effect. The percen
tage of energy from saturated fat decreased 0.7% (95% confidence interval -
1.4 to - 0.1) and percentage of energy from polyunsaturated fat increased
8.4% (95% confidence interval 0.0-0.7) in women, and appears to be a time e
ffect. However, the increase in saturated fat and decrease in polyunsaturat
ed fat with advancing age seen cross-sectionally suggests a cohort effect a
lso occurring. In 1995/96, more people were using margarine as a spread and
vegetable oils to cook meat. Milk and milk product consumption increased (
not significantly), and meat intake decreased significantly by 5 and 4 serv
ings per month in men and women, respectively. There was an increase in the
proportion of people who ate breakfast cereal at feast once a week, and mo
re women ate brown or wholemeal bread in 1995/96.
Conclusion: Over the 6 y follow-up period studied, there was no indication
of an age effect on nutrient intakes in adults aged 70 y and older; however
, the changes occurring over time demonstrate that older adults, particular
ly women, are making changes towards healthier food choices.
Sponsorship: Health Research Council of New Zealand and the University of O
tago Medical School.