The WHO has declared overweight and obesity as one of the top 10 risk conditions in the world and one of the top 5 in industrialized countries.1 Studies on twins, adopted children, family aggregation and ethnic groups confirm the contribution of genes to the development of obesity.2–4 Obesity-predisposing genes encode the molecular components of the physiological systems regulating energy balance, i.e. energy intake and expenditure, and consequently body composition (including fat stores).5 Studies of ethnic groups and in developing countries support the thrifty genotype hypothesis whereby genes, selected through the million-year-long era of hunter–gatherers to afford a specific environmental pattern (including several hours of physical activity per day, continuously alternating of periods of feast with famine, etc.), are nowadays believed to predispose to obesity and diabetes.6 Actually this purported predisposing genetic pattern, developed to save energy, has produced an increasing prevalence of Overweight and Obesity in the agricultural (last 8–10,000 years) or recent industrialized (last 200 years) societies. The obesity epidemics actually exploded, as clearly appears in the US society, particularly in developing ages and in non caucasian populations, from the “80s onward, in less than one generation and not during the whole last century!”7,8 This is clearly confirmed by the massive epidemics of obesity and diabetes in aboriginal societies, very recently faced with westernized life styles.6 New, aggressive environmental and cultural factors have certainly played a role. As a matter of fact, food industry is currently able to manipulate the so called “food pyramid” by encouraging the consumption of low fat foods however enriched in simple sugars able to produce insulin-resistance and elevated post-prandial metabolic efficiency just as the harshly “banned” saturated fats do.9,10 This has led a tremendous confusion among the “consumers” and unspecialized physicians who have become “attracted” by irrational alternatives.11,12 Extreme but unrecognized sedentarism, in everyday work and leisure activities, and in the time spent to reach the working place, as well as the increase in elderly population have also reached their historical peak and do not tend to plateau. The whole process appears to be irreversible and spread all over the world! Nevertheless, overweight and obesity epidemics seem concomitant with another aspect of the very recent globalization process, the worldwide homogenization of the genetic and environmental, as well as socio-economic and cultural determinants.13 In other words, can the irreversible loss of the ethnic (biological and cultural) variety “per se”, mostly due to progressive and massive urbanization and humanization of the territory, negatively affect our health? We would like to comment on this, drawing some insight from Claude Levy Strauss's anthropological–cultural view starting from some of his basic concepts. Levy Strauss assumed that ethnic groups tended to distinguish each other simply because men, at the beginning, were few and aggregated in small groups: they therefore differentiated each other culturally (but also genetically—possibly through the occurrence of specific polymorphisms—by an environmental adaptation to improve individual, and group, health and survival). He calls that by the end of the XIX century more than 3500 different human societies were living all over the world: now most of them are definitely extinguished (with the consequent loss of their genetic and environmental identity and variety…and contribution to health!). Ethnic differences, Levy Strauss recalls, are creative and produce progress and evolution: thus health as natural consequence of the improved adaptation to the different environments.14