Activity levels and body mass index of children in the United States, Sweden, and Australia

Purpose: Assess the physical activity and body mass index (BMI) levels of children in the United States, Sweden, and Australia. Methods: A total of 1954 children, 6-12 yr old (711 American, 563 Australian, and 680 Swedish) wore sealed pedometers for four consecutive days. Height and weight measures were obtained. Results: Descriptive data for step counts and BMI by sex, age, and country were calculated to determine activity levels and BMI. Three-way multivariate ANOVA for step counts and BMI between countries at each age and sex found that, in general, the Swedish children were significantly more active than the Australian and American children, and the American children were significantly heavier than the Australian and Swedish children. For boys, the mean step counts ranged from 15,673 to 18,346 for Sweden, 13,864 to 15,023 for Australia, and 12,554 to 13,872 for America. For girls, the mean step Counts ranged from 12,041 to 14,825 for Sweden, 11,221 to 12,322 for Australia, and 10,661 to 11,383 for America. The activity curve is somewhat level during the preadolescent years. The rate of increase in BMI with age is much greater in the American children than in the Swedish or Australian children. The percent of American, Swedish, and Australian boys classified as overweight/obese was 33.5, 16.6, and 15.8, respectively. The percent of American, Swedish, and Australian girls classified as overweight/obese was 35.6, 16.8, and 14.4, respectively. Correlation analysis found few significant negative relationships between step counts and BMI. Conclusions: American children tend to be the least active and heaviest with the greatest rate of increase in BMI. The Swedish children are the most active group followed by Australia. Swedish and Australian children maintain lower BMI throughout their prepubescent years than do the American children who have a greater percentage who are classified as overweight.