The dramatic changes in the lifestyle of many Asian communities, and the resultant changes in the food and nutrition issues facing the communities in the region have been documented by various investigators. Health authorities and researchers have given greater attention to the problem of overweight and obesity. Available data are lacking, but various estimates have indicated that the emerging problem of overweight amongst children cannot be ignored. Estimates of overweight by the World Health Organization (WHO) amongst preschool children in Asia in 1995 was around 2.9%. Data extracted from selected studies in individual Asian countries show much higher prevalences, ranging from 5% to 9% amongst several urban cities in Asia. In several other developing countries in the region, the prevalence is probably very low, with prevalences of less than 1%. There is thus considerable variation in this prevalence amongst the various countries. The problem of increasing overweight and obesity amongst adults in Asia has been highlighted for more than a decade. The database on the extent of the problem is far from being comprehensive, but various studies have pointed out the severity of the problem. Various reports in the 1990s have pointed out prevalences of overweight of over 20% and obesity of over 5% amongst urban population groups of the more developed countries in the region. It is also to be noted that there are also reports indicating that the most affluent societies in the region, such as Seoul and Tokyo, did not have the highest prevalence of overweight. There are also data on increasing prevalence of overweight among rural areas in the last 10 years. The situation for children is similar: there is considerable variation in the severity of the problem. In the Philippines National Surveys, for example, slightly lower prevalences have been reported. Countries in the region will continue to progress, accompanied by continued changes in lifestyle of communities. It is therefore of utmost importance to continue to monitor the nutritional status of communities. The lack of nationally representative data which is regularly updated is a major concern. The lack of data for certain age groups such as the adolescents and the elderly need to be addressed. One of the main obstacles in the formulation and effective implementation of intervention programs in developing countries is the lack of comprehensive data on the extent of the problems in many cases and the causes of such problems specific to the communities concerned. In addition to the lack of good data, other concerns too need to be addressed. These include methodological issues such as the need for harmonization of methods in assessment of nutritional status for the various groups, the appropriateness of criteria for cut-offs, growth reference to be used, and association of overweight and obesity with comorbidities.