The recent increases in child overweight and obesity are largely attributed to social and environmental forces which are not under the individual control of children and which, in turn, influence eating and physical activity behaviors (9). Children are exposed to obesogenic environments and the school is one of the many environments in which children may be exposed to 'obesogens' (10). Important social changes have affected family eating patterns and the consumption of fast foods, pre-prepared meals, and soft drinks. Likewise, the amount of physical activity that children engage in has been reduced by an increase use of cars, an increase in the amount of time spent watching television (with multiple TV channels around the clock) and playing sedentary games, and a decrease in the opportunities for physical activity on the way to school, at school, or during leisure time.

According to WHO (2000) 20% of children in U.K., U.S.A. and Australia are currently overweight (11). Similarly, a recent global analysis showed a rising trend in childhood overweight in 16 out of 38 developing countries with more than one national survey(12). In India also an 'urban, rural divide' scenario has emerged related to nutrition. In children, the difference between the rich and the poor is fairly evident in recently conducted urban studies. Ramachandran, et al. studied children from six schools in Chennai, two each from high, middle and lower income groups(13). The prevalence of overweight (including obese) adolescents ranged from 22% in better off schools to 4.5% in lower income group schools. In a Delhi school with tuition fees more than Rs. 2,500 per month, the prevalence of overweight was 31%, of which 7.5% were frankly obese(14). In Pune the figures for overweight children are 24% in a well off school and 6% in a 'corporation' school. Another area of concern for the epidemiologist has been rapid weight gain. Longitudinal data indicate that sustained and accelerated childhood weight and BMI gain (crossing into higher categories) is associated with adult morbidity including diabetes, hypertension and coronary artery disease. Interestingly many children and adolescents with Insulin resistance are not overweight by International standards though getting bulkier relative to themselves (15). It signifies that an individual child need to be monitored with regular weight and or serial BMI measurements. Realizing that Indians are at risk of metabolic diseases at lower level of weight, the International Obesity Task Force (IOTF) has proposed the standards for adult obesity in Asia and India as BMI >23 as overweight and BMI >25 as obesity (16).