Abstract: The problem of obesity was only accepted by the World Health Organization as of major public health importance in 1997 when the criteria for the specification of the metabolic syndrome were also being sought. Then the risk factor analyses of the determinants of global ill health at the start of the millennium showed that an excessive body mass index (BMI) above the optimum of 21 was one of the top 10 contributors. No analyses could be related to abdominal obesity because of the absence of systematic representative surveys of waist circumferences but the ill health attributable to excess weight included the risk factors specified in the metabolic syndrome and showed that the co-morbidities in Asia were far greater than those predicted from simply an excess weight. The recent proposed definition of the metabolic syndrome includes these different criteria specified on an ethnic basis but there is now a need to recognize that abdominal obesity is more common on the developing world and linked to childhood stunting and early deprivation. The importance of intrauterine and postnatal epigenetic and altered organ function needs to be recognized. Thus the co-morbidities associated with weight gain and the development of the metabolic syndrome dominate in the developing world where the majority of the population is proving more susceptible to the effects of weight gain than Caucasians now living in affluent societies. This therefore presents a major challenge in both research and public policy terms.