This study was performed to document the weight loss diet practice and dietary habit related to weight control in child-bearing Korean women. The subjects were 1,434 women aged 17-39 years. The subjects were classified into 3 groups based on BMI: low weight(LW) BMI < 18.5; normal weight(NW), 18.5 BMI 22.9; and overweight(OW), 23.0 BMI. Anthropometric, general characteristics, weight control practice, and the quality of diet were assessed by a questionnaire. LW group had higher rate of smoking and drinking. They also complained more subjective symptom of anemia and used less nutritional supplementation. Weight loss diet had been practiced by about 40% of subjects and the percent was increased with increasing BMI. The reason of weight loss diet were significantly different by BMI groups(p<0.05); LW to keep body in shape, OW for health. Low BMI group had experienced more side effects after weight loss diet(p<0.05). LW group usually used inappropriate method to control weight such as skipping meals and some of OW group reported using drug to lose weight. All subjects have been skipped their meals of 3.9 times per week, especially 4.3 times in LW group. By mini dietary assessment, most of the subjects did not have regular meals. LW group tended to eat what they like and OW group preferred fried food. This study showed that child-bearing aged women make a ceaseless effort apart from their weight, and LW group have a matter of grave concern because of their dietary habit and weight control practice. Additional research should be necessary to assess the relation of health and weight loss diet in young women.