Lack of exercise may be one of the main causes of obesity in the recent modernized society. With the rapid increase of obese population worldwide, the economic costs of overweight have become a great burden in many countries. The costs of obesity may be divided into the direct costs to the health system and the indirect or social costs to the individuals and the community (for example, sick days and individuals' expenditure on weight loss). The direct costs depend on the main part of the diseases caused by obesity and the cost of these diseases. Some diseases thathave been included in the calculation are Type 2 diabetes, heart disease, hypertension, endometrial cancer, arthritis and colorectal cancer. One of the problems in this assessment is the relative risk of the diseases in different communities and ethnic groups. Several methods have been used to calculate these costs and produceda wide range of results from different countries. One of the latest estimates ofcosts of obesity is from the United States and was 10.2% of the total health care cost. Little data is yet available in Asian countries ; however, the Korean Obesity Society reported a total cost of obesity estimated at about 0.11% of GDP or about 2.13% of the total health care cost. It is now necessary to develop a strategy for life style modifications at the nationwide level.