Abstract
Objective To evaluate the effectiveness of a weight-control intervention for overweight subjects at high risk of cardiovascular disease (CVD) at a worksite conducted by medical students as a public health practical training program.
Methods A total of 45 men and women who were obese (BMI>=24.0 kg/m2) and found to be hypertensive (SBP>=140 mmHg or DBP>=90 mmHg) or suffering from hypercholesterolemia (total serum cholesterol >=220 mg/dl) in an annual health check up in November 2001 were invited to participate in a weight-control intervention program. Eight individuals agreed (intervention group) and other sixteen control subjects whose sex and age (+/− 3 years) were matched to the intervention subjects were selected. The duration of the program was three months (from July to October 2002) and a 2 kg weight reduction in that period was set as the goal. The baseline survey consisted of a dietary questionnaire and a health quiz. Subjects had two counseling sessions and received four personal letters in the three months. A semi-quantitative food frequent questionnaire, a photograph method (Diet Agent Service, Matsushita Electric Works, Ltd.) and three day food records were conducted for dietary surveys. Changes in bodyweight, BMI, blood pressure, and serum total cholesterol concentration from November 2001 to November 2002 were compared between the intervention and control groups. Food group intakes and nutrient intakes were compared between weight reduction achievers and non-achievers.
Results Mean bodyweight changes from November 2001 to November 2002 were −2.3 kg (SD 3.3 kg) for the intervention group and +0.3 kg (SD 1.5 kg) for the control group, the difference being significant (p=0.013). For the intervention group mean bodyweight change from July to October 2002 was −1.5 kg (SD 2.4 kg). For total serum cholesterol, the mean changes were −32.1 mg/dl vs. +0.5 mg/dl (p=0.005), for SBP −9.5 mmHg vs. +4.7 mmHg (p=0.083) and for DBP −2.8 mmHg vs. +1.4 mmHg (p=0.438). These were thought to be consequences of weight-control intervention. From dietary surveys, weight reduction achievers increased fish intake and decreased fats, snacks and sweets. Those who answered the health quiz more correctly demonstrated more reduction of bodyweight.
Conclusions Effectiveness of a weight-control intervention for reduction of CVD risk factors was found in the present public health practical training program for medical students. Dietary advice based on various dietary surveys was indicated to be effective in the weight-control program. A population strategy to distribute health information appeared necessary for effective health education programs for high-risk subjects.
