Despite mounting public health warnings about obesity, researchers at the University of Michigan know for a fact that young women in their '20s consistently exercise less than their male counterparts in the same age bracket.
According to the study, young black women showed significant declines in exercise between 1984 and 2006.
The study is one of the first to analyze long-term patterns in weight-related activities, and to assess how these patterns vary by gender, race and ethnicity, and socioeconomic status.
According to Philippa Clarke, lead author of the study and a researcher at the U-M Institute for Social Research (ISR), the study reveals that the disparities in health behaviours are consistent with disparities in the prevalence of obesity, particular among women.
The study is based on data obtained every two years from 17,314 men and women who were aged 19 to 26 between 1984 and 2006. The participants were part of a follow-up panel drawn from the Monitoring the Future Study, conducted by ISR.
For the study, the researchers looked at trends over a 23-year-period in six different health behaviours. They measured how often participants reported eating breakfast, and eating at least some green vegetables and fruit; how often they exercised vigorously (jogging, swimming, or calisthenics); how often they got at least seven hours of sleep, and how much television they watched on an average weekday.
"Agreement is growing that the source of the obesity epidemic lies in an environment that produces an energy gap, where energy intake exceeds energy expenditure even by as little as 100 excess calories per day," said Clarke and co-authors Patrick O'Malley, Lloyd Johnston, John Schulenberg and Paula Lantz, all researchers at ISR.
The study is to be published in the October issue of the American Journal of Public Health.