Physical inactivity is one of major risk factors of obesity-related disease. Scientific data are, however, essential to encourage residents to increase physical activity.
Methods: The Sapporo lifestyle study is a community-based, prospective, randomized controlled trial to evaluate improvement of lipid risk profile by exercise and dietary intervention for 12 months. 316 asymptomatic residents were recruited by mail to participate in the study with informed consent. Eligible residents were allocated into 3 groups, consisting of 105 in the control (A), 106 in the exercise intervention (B) and 105 in the exercise and nutritional modification (C) groups. Brisk walking for 150 min a week was introduced to the B and C groups, and dietary modification was encouraged for the C group. Body composition, lipid profile, physical fitness, and nutritional status (by diet history questionnaire made in Japan NIH) were estimated for all participants at the beginning and end of the study, and they were monitored on daily physical activity by pedometer during the study.
Results: Computerized randomization by minimization method was successful, resulting in no significant differences of major risk factors. A total of 249 residents (A: 87, B: 78, C: 84) were followed up for 12 months (follow-up rate 79%). The B and C groups had significantly increased brisk walking than that of the A group. Lipid profile was improved in all groups. Above all, HDL-C levels increased by 0.31, 2.47 and 3.62 mg/dl in A, B and C groups (p < .05). Although intakes of total energy and cholesterol per 1,000 kcal a day were reduced in all groups, n-3 PUFA per 1,000 kcal significantly increased in only the C group (p < .05).
Conclusions: Brisk walking resulted in a marked increase of HDL-C level, which accounts for a good prognosis in a population with high PA.