Childhood obesity is a nationwide epidemic. It is recognized that being overweight or obese during childhood has a substantial effect on physical and psychological health. The instrument of obesity advancement is not fully recognized and it is considered a problem with various causes. Ecological factors, lifestyle preferences, and cultural upbringing play a critical role in the increasing pervasiveness of obesity globally. In general, overweight and obesity are expected to be the product of increased caloric and fat intake. On the other hand, there is evidence that disproportionate consumption of sugar in soft drinks, increases in portion sizes, and continued declines in physical activity have played a key role in increasing levels of obesity all over the world. (Dehghan, Akhtar-Danesh and Merchant, 2005). Although the definition of obesity and overweight has changed over time, it can be defined as excess body fat (BF). There is no consensus on a threshold for excess fat linked to overweight or obesity in children and adolescents. The Center for Disease Control and Prevention has defined overweight as being at or above the 95th percentile of BMI for age and "at risk of overweight" between the 85th and 95th percentile of BMI for age ( Dehghan et al., 2005). Nearly all researchers agree that prevention could be the important plan to control the current obesity epidemic. So far, most methods have focused on changing people's behavior around diet and exercise. However, it appears that these approaches have had a modest impact on the growing obesity epidemic. While about fifty percent of adults are overweight and ob...... middle of paper ......ces.yahoo.com/childhood-obesity-caused-poverty-320094.html Ogden, CL, Lamb , MM, Carroll , MD and Flegal, KM, (2010). Obesity and socioeconomic status among children and adolescents: United States, 2005-2008. U.S. Department of Health and Human Services. Retrieved from http://www.cdc.gov/nchs/data/databriefs/db51.pdf Ogden, CL, Carroll, MD, Kit, BK and Flegal, KM, (2012). Obesity prevalence and body mass index trends among US children and adolescents, 1999-2010. Journal of the American Medical Association, 307(5):483-490. doi:10.1001/jama.2012.40Wang, Y. and Zhang, Q., (2006). Are American children and adolescents from low socioeconomic backgrounds at increased risk of obesity? Changes in the association between overweight and family income between 1971 and 2002. American Journal of Clinical Nutrition, 84:707–16.