Recreational physical activity and ten-year weight change in a US national cohort.
Clinical research has established that increases in physical activity cause weight loss among the obese, but less is known about the influence of physical activity on longer-term weight change in the general population. Data from the NHANES-I Epidemiologic Follow-up Study (1971-1975 to 1982-1984) were used to examine the relationship between self-reported recreational physical activity level (low, medium, high) and measured weight change after ten years among 3515 men and 5810 women aged 25-74 years. Cross-sectional analyses at both the baseline and follow-up surveys revealed that recreational physical activity was inversely related to body weight. Low recreational physical activity reported at the follow-up survey was strongly related to major weight gain (> 13 kg) that had occurred during the preceding ten years. The estimated relative risk of major weight gain for those in the low activity level at the follow-up survey compared to those in the high activity level was 3.1 (95% Cl = 1.6-6.0) in men and 3.8 (2.3-6.5) in women. In addition, the relative risk for persons whose activity level was low at both the baseline and follow-up surveys was 2.3 (0.9-5.8) in men and 7.1 (2.2-23.3) in women. However, no relationship was found between baseline physical activity level and subsequent weight gain among either men or women. The lack of a relationship may be due to mis-specification of physical activity because of changes in activity over time. These findings suggest that low physical activity may be both a cause and a consequence of weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Health and Human Services, National Center for Chronic Disease Prevention and Health Promotion, Atlanta, GA 30333.
D F
DF
Williamson
J
J
Madans
R F
RF
Anda
J C
JC
Kleinman
H S
HS
Kahn
T
T
Byers
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D001835:Body Weight; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D015430:Weight Gain