(CBS Sports) – Both lack of exercise and consuming too many calories can certainly contribute to gaining extra pounds, but a new study suggests that the former may be the main culprit in the obesity epidemic in the U.S. And women younger than 40 appear to be particularly vulnerable to the risks of a sedentary lifestyle.
The study, published July 7 in the American Journal of Medicine, found that in the last 20 years, the number of women in the U.S. who reported no physical activity in their free time increased from about 19 percent in 1994 to nearly 52 percent in 2010. In men, the number rose from about 11 percent in 1994 to 44 percent in 2010. Meanwhile, the average BMI (body mass index) increased by 0.37 percent per year in both men and women, rising most dramatically in women ages 18to 39. During the same time period, overall caloric intake did not change.
“Our findings do not support the popular notion that the increase of obesity in the United States can be attributed primarily to sustained increase over time in the average daily caloric intake of Americans,” study author Dr. Uri Ladabaum, an associate professor of medicine at Stanford University School of Medicine, wrote in the study.