Obesity and the metabolic syndrome in developing countries: focus on South Asians.

With improvement in the economic situation, an increasing prevalence of obesity and the metabolic syndrome is seen in developing countries in South Asia. Particularly vulnerable population groups include women and children, and intra-country and inter-country migrants. The main causes are increasing urbanization, nutrition transition, reduced physical activity, and genetic predisposition. Some evidence suggests that widely prevalent perinatal undernutrition and childhood 'catch-up' obesity may play a role in adult-onset metabolic syndrome and type 2 diabetes. Data show that atherogenic dyslipidemia, glucose intolerance, thrombotic tendency, subclinical inflammation, and endothelial dysfunction are higher in South Asians than white Caucasians. Many of these manifestations are more severe even at an early age in South Asians than white Caucasians. Metabolic and cardiovascular risks in South Asians are also heightened by their higher body fat, truncal subcutaneous fat, intra-abdominal fat, and ectopic fat deposition (liver fat, muscle fat, etc.). Further, cardiovascular risk cluster manifests at a lower level of adiposity and abdominal obesity. The cutoffs of body mass index and waist circumference for defining obesity and abdominal obesity, respectively, have been lowered for Asians, and same has been endorsed for South Asians in the UK. The economic cost of obesity and related diseases in developing countries, having meager health budget, is enormous. Increasing awareness of these noncommunicable diseases and how to prevent them should be focus of population-wide prevention strategies in South Asian developing countries. Community intervention programs focusing on increased physical activity and healthier food options for schoolchildren are urgently required. Data from such a major intervention program conducted by us on adolescent urban schoolchildren in north India (project MARG) have shown encouraging results and could serve as a model for initiating such programs in other South Asian developing countries.