PURPOSE: To determine the frequency of past and present obesity among patients with NIDDM and to identify the differences of body fat, blood pressure and C-peptide/glucose ratio according to obese diabetic patients (BMI> or =25 kg/m2) and nonobese (BMI<25 kg/m2). Also the final factor is to observe the anthrometric change patterns in the study. METHOD: The weight at 20 years-old, previous maximal body weight, and acute weight loss were queried. Current height, body weight, BMI, waist & hip circumferences, waist-hip ratio, skinfold thicknesses, blood pressure, fasting blood glucose, and fasting C-peptide were measured in one hundred sixty-seven NIDDM patients. The differences of the parameters ccording to obese and nonobese, and three anthropometric change patterns were analyzed. RESULT: Results were as follows: 1. 66.5 % of the NIDDM patients had a history of past obesity as assessed by their maximum weight, while only 33.2% of them were currently obese (p's < 0.001). 2. The waist & hip circumferences, skinfold thicknesses, systolic, diastolic & mean arterial blood pressure in obese patients were greater than those of nonobese patients (all p's < 0.001). 3. The waist and the hip circumferences, and skinfold thicknesses (subscapula & triceps) were highest among the obese-obese group. WHR and abdominal skinfold thickness in the obese-obese and obese-nonobese groups were higher than those in the nonobese-nonobese group. Systolic & diastolic and mean arterial blood pressures in the obese-obese group were higher than those of obese-nonobese and nonobese-nonobese groups (all p's < 0.005).4. The abdominal and subscapular skinfold thicknesses in female diabetic patients were greater than those of male patients (all p's <0.0001). CONCLUSION: Although most Korean NIDDM patients were previously obese, many of them were not obese during the course of the study. Greater central and upper body adiposicity and higher blood pressure was shown in obese diabetic patients. Also, greater central and upper body adiposicity was demonstrated in female diabetic patients.