The purpose of this research is to investigate how obesity and eating behavior are related to the concentration of serum insulin and lipids and blood pressure of middle-aged men The sample for this study utilizes 240 middle-aged men between th4 age of 40 and 60 living in the city of Kumi. Through a process of anthropometry and categorization by relative body weight, the sample is devide into two groups, the obese group (51 men) and the normal group (129 men). The results of the study were as follows : 1111111. The men from the obese group with the exception of height, subs-capular/triceps skinfold girth ratio(STR) had a higher level of body mass index (BMI), waist and hip circumference, waist/hip girth ratio(WHR), subscapular and triceps skinfold thickness than the normal group (P=0.0001). 2. In comparing the serum insulin and lipids between the obese and normal group, the obese group had a higher level of insulin and triglyceride (P=0.016, P=0.050) but a lower concentration of HDL-cholesterol and HDL-cholesterol/total cholesterol (P=0.034, P=0.004). Also, the obese group had a higher level of systolic and diastolic blood pressure (P=0.001, P=0.029). When looking at the relationship between the serum insulin and lipids and anthropometric measurements, the relationship between waist/hip girth ratio(THR), the concentration of fasting serum insulin and lipids were stronger than the obesity index, body mass index(BMI). 3. Men who exercised regularly had a lower total cholesterol and systolic blood pressure 9P=0.049, P=0.041), and a higher level of HDL-cholesterol/total cholesterol (P=0.004). There was no observable relationship between the food habit score, the preference for fiber foods, and the concentration of serum lipids. Also, the concentration of serum lipids had no apparent effect on the preference for salty, sweet, and greasy foods.