The purpose of this study was to examine the effect of a health education program for reducing body weight via E-mail, which was presented by a company for their employees as one of the methods of health promotion. We recruited subjects via the intranet, and fifteen people who had no metabolic disease and whose body mass index (BMI) was over 25 participated in the program. Before the program commencement, a questionnaire concerning eating habits was administered, and we decided on the targets for improving the eating habits of each individual. Using of a self-monitoring method, the subjects recorded their body weight and whether they achieved their own targets every day. The subjects sent their record every two weeks, and a dietician responded to them with dietary advice. Eight weeks after starting the program, we asked again about eating habits.   The percentage of subjects who submitted all records during the program was 86.7%, and the average weight reduction was 2.4±1.5 (Mean±S.D.) kg. After the program, eating habits improved, especially “Reviewing their own eating habits”,“Reducing the use of mayonnaise or oil dressing”, Referring to the nutritional indication when they choose their meal”, “Do not eat too much at supper”, and “Not eating within two hours before bedtime”. There was a significant positive relationship between the points of improving eating behavior and reducing body weight (p<0.01). In this study, we clarified that the health education program via E-mail had a positive effect on improving eating habits and led to body weight reduction.