Most of college women are interested in their appearances, and those whose body weights are normal or even underweight try to lose weight. Many methods for weight control diets practiced by college women are unsound and irrational so that some side-effects should be watched out. The present study was aimed to investigate methods of diets, food habits, behaviors, and side effects of weight control and to suggest sound weight loss schemes for college women. The subjects were 353 college women living in Taegu and Kyung Buk area, comprising 178 women who have tried weight control diets and 175 women who have not tried diets. The items included in questionnaires were food habits, food behavoirs, food frequency, physical activity status, 24-hour daily activity record, height, weight, etc., and the survey was conducted in September 1997. There was no difference in body mass index between college women who have tried diets(20.1$pm$2.26) and women who have not tried diets(19.3$pm$1.58), and 24.2% of those who have tried diets had body mass index under 19. The leading reason for diets was to make better fitting for costumes(67%). While women who have tried diets also tried to exercise more, they tended to overeat than women who have not tried diets. Mean of food habit scores(9.33 vs 9.32) which corresponded to "poor" habit and food frequencies were not different with or without experiences of diets. This indicated that diets were not related to actual changes of food habits and food intakes. Diet methods used frequently by college women were relying on special diet foods(25.4%), fasting(24.9%) and exercise(22.6%). Trying both exercise and diet was practiced by only 5.1% of the subjects who have tried diets. The duration time of diets was mostly in the range of 1 week to 1 month, and the longer diet period was, the more weight loss was. The frequent side effects due to diets were anemia(41.8%) and enervation(23.7%). Activity coefficients were lower in those who have tried diets(1.38$pm$0.13) than those who have not tried diets(1.41$pm$0.19). Women who have tried diets spent more time on reading newspapers and magazines and on watching TV. This study indicates that college women who have tried diets practiced irrational diets for weight reduction and experienced undesirable side-effects. Therefore scientific and systematic weight reduction programs accompanying balanced diets and proper exercise with behavior changes should be developed.