U. MICHIGAN (US)—Young women in their 20s consistently exercise less than men, according to a new study that is the first to examine patterns of weight-loss activities across gender, race, ethnicity, and socioeconomic status.
The University of Michigan study also indicates that black and Hispanic women in particular exercised less, slept less, and were less likely to eat breakfast, and consumed fewer fruits and vegetables than white women.
The findings will be published in the October issue of the American Journal of Public Health.
Philippa Clarke, lead author of the study and a researcher at Michigan’s Institute for Social Research, says the disparities in health behaviors 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.
Researchers looked at trends over the 23-year-period in six different health behaviors, measuring how often participants reported eating breakfast and consuming 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,” the study authors report.
The frequency of eating fruits and vegetables remained steady in young women and declined significantly in young men, who also reported eating breakfast less often than women.
The study also found that young women consistently exercised less than young men, adding support to the theory that differences in energy expenditure play a role in gender disparities in obesity.
While being a “couch potato” has been called an important factor in weight gain, the amount of time both women and men spent watching television remained relatively stable. Both men and women reported steady decline in the frequency of getting at least seven hours of sleep each night.
When the researchers compared behaviors of different racial and ethnic groups, they found some major differences across the board.
For example, although white women showed a steady increase in the frequency of eating breakfast, the trajectory for non-Hispanic black women declined until 1996 and only began to increase in 2000, and fruit and vegetable consumption was lower among black and Hispanics of both genders in any given year.
Among men, those from lower socioeconomic backgrounds reported dramatic declines in sleep, after adjusting for race and ethnicity. Minority racial and ethnic groups, and women from lower socioeconomic groups, also reported watching television more often than whites and women from more affluent backgrounds.
The analysis was funded by the Robert Wood Johnson Foundation, as part of the Youth, Education, and Society Project, based at the Institute of Social Research.
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