Height and body weight in elderly adults: A 21-year population study on secular trends and related factors in 70-year-olds

Background. Body size in elderly adults is partly due to aging and partly to secular trends. This study describes secular trends in three anthropometric measures (i.e., height, body weight [BW], and body mass index [BMI]) of 70-year-olds over a period of 21 years and their relation to social and lifestyle factors. Methods. A total of 3128 70-year-olds from four birth cohorts born between 1901 and 1922 in Gothenburg, Sweden, were examined between 1971 and 1992 in the Geriatric Medicine Department, Göteborg University. Trends in anthropometric measures were examined by permutation test. Influence of the subjects' birth year, physical activity, smoking habits, and education on anthropometric measures were investigated by multiple linear regression. Results. Individuals in later-born cohorts were found to be 1 to 2 cm taller and 1.5 to 6.3 kg heavier than earlier-born cohorts. For BMI, a positive trend was significant only in 70-year-old male participants. "Year of birth" was a positive predictor for BW (p < .001) and BMI (p < .001) in male participants and for height (p < .05) and BW (p < .01) in female participants. Physical inactivity was a positive (p < .01) and "current smoking" a negative (p < .001) predictor for BMI in both sexes. "More than basic education" was a positive predictor for height (p < .001) in both sexes and a negative predictor for body weight (p < .01) and BMI (p < .001) in female participants only. Conclusions. Trends of increasing height, BW, and BMI were found among the Swedish elderly participants. This may be partly due to differences in smoking habits, physical activity, education, food habits, childhood nutrition, and living conditions between the cohorts.