It s been well established that physical activity can help ward off or ameliorate various ailments, ranging from arthritis to heart disease, and may even help prolong life. But the extent to which such benefits are associated with obesity, or how much exercise is needed hasn t been clearly defined.
To help identify which factors were involved in prolonging lives and their association with obesity, Dr. Ulf Ekelund and colleagues from 23 centers in 10 European countries evaluated data from a large prospective cohort study. This study of European men and women (the EPIC study) followed over 117,000 men and women for over 12 years.
Initially, the participants had their height, weight and waist circumferences (WC) measured, and their BMIs were calculated. The researchers categorized their physical activity levels in the past year from either personal interviews or from questionnaires, and divided participants into 4 groups inactive, moderately inactive, moderately active, and active. Then they evaluated the associations between BMI, WC and the risk of death. BMI is an index of overall adiposity, while WC indicates the degree of abdominal fatness.
The researchers found that the greatest reduction (16-30 percent) in the risk of death was seen in the comparisons between the moderately active and inactive groups, across the levels of BMI and WC. This indicates that even in obese, sedentary people, just a small increase in activity level can be beneficial.
Indeed, they calculated that brisk walking for about 20 minutes per day by inactive individuals could reduce the risk death significantly.
The authors noted that of the approximately 9 million deaths in Europeans in 2008, based on the current study, 337,000 may have been linked to obesity, but twice that number may have been attributed to physical inactivity.
ACSH s Dr. Ruth Kava commented These data are indeed intriguing I don t think that previous studies have indicated such a relatively large benefit from such a small amount of exercise. Hopefully, inactive individuals whether obese or not will pay attention to these results and alter their lifestyles accordingly.