Update in the management of obesity.

Significant increase of obesity prevalence in almost all countries in the world recently has had obesity as a global health problem, and WHO in 1998 defined it as "the global epidemic". Simply, obesity is defined as an excessive fat accumulation in fat tissue due to imbalance of energy intake and expenditure. Body mass index is a simple method for defining the degree of overweight and obesity, however, waist circumference is the preferred measure of abdominal obesity because it has greater relationship with the risk of metabolic and cardiovascular diseases. Body fatness reflects the interactions of development, environment and genetic factors. The role of genetic factors has already existed, nevertheless, environment factors are likely more important in developing obesity. Increased mortality among the obese is evident for several life-threatening diseases including type 2 diabetes, cardiovascular disease, gallbladder disease, and hormone-sensitive and gastrointestinal cancers. Risks are also higher for some non-fatal conditions such as back pain, arthritis, infertility and, in many westernized countries, poor psychosocial functioning. Obesity is not only threatening health, also impacts on high economic and social cost. Effective prevention of obesity should be focused to high risk individuals or groups. Individuals who have some existing weight-related problems and those with a high risk of developing obesity co-morbidity such as cardiovascular disease and type 2 diabetes should be a key priority in this prevention strategy. Although weight loss in obese persons of any age can improve obesity-related medical complications, physical function, and quality of life, the primary purpose for weigh-loss therapy may differ across age group. The current therapeutic tools available for weight management are: (1) lifestyle intervention involving diet, physical activity, and behavior modification; (2) pharmacotherapy; and (3) surgery. Moderate weight loss (5-10% of initial weight) by any programs is a realistic target in management of obesity associated with improvement of risk factors of metabolic and cardiovascular diseases.