Regular exercise may prevent middle-age weight gain

A new study has revealed that young adults, particularly women, who maintained high levels of moderate and vigorous activity over a period of 20 years experienced smaller gains in weight and waist circumference during the transition from young adulthood to middle age, compared to individuals with lower activity levels.

Arlene L. Hankinson, of the Feinberg School of Medicine, Northwestern University, Chicago, and colleagues conducted a study to evaluate the relationship between maintaining higher activity levels and changes in body mass index (BMI) and waist circumference over 20 years in young adults.

The study is a prospective study with 20 years of follow-up, 1985-1986 to 2005-2006.

Habitual activity was defined as maintaining high, moderate, and low activity levels based on sex-specific groupings (by thirds) of activity scores at the beginning of the study.

The study included 3,554 men and women, ages 18 to 30 years at the beginning of the study, from Chicago; Birmingham, Ala.; Minneapolis; and Oakland, Calif.

The researchers found that over the study period, maintaining high levels of activity was associated with smaller gains in BMI and waist circumference compared with low activity levels after adjustment for race, baseline BMI, age, education, cigarette smoking status, alcohol use and energy intake.

Over 20 years, men maintaining high activity gained 2.6 fewer kilograms and women maintaining higher activity gained 6.1 fewer kilograms and men maintaining high activity gained 3.1 fewer centimeters in waist circumference and women maintaining higher activity gained 3.8 fewer centimetres.

The authors add that weight gains in participants with moderate or inconsistent activity levels generally were not different from the low-activity group.

“Importantly, women seemed to benefit the most from maintaining higher activity; the magnitude of weight change was more than twice as large among women compared with men. Similarly, participants who maintained the Health and Human Services-recommended 150 minutes of moderate activity per week gained significantly less weight compared with participants who did not,” the authors said.

The study has been published in the December 15 issue of JAMA.