Overweight and obesity have become urgent global health issues in recent decades. Globally, the number of overweight children under the age of 5 years has increased from 32 million in 2000 to 41 million in 2014, corresponding to an increase in prevalence from 5.0% to 6.1%. It is estimated that, at the current pace, by 2020 some 9% of all children under 5 years will be overweight. Furthermore, an increase in adult obesity prevalence has been observed in all countries, and globally the prevalence of obesity among adults has doubled from 1980 to 2014, from 5% to 11% for men and from 8% to 15% for women. Overweight and obesity were estimated to account for 3.4 million deaths annually and 93.6 million disability-adjusted life years (DALYs) 1 in 2010. The burden of overweight and obesity is inequitably distributed and affects some population groups and geographical areas more than others, based on their social characteristics, which are also inequitably distributed. Vulnerability to overweight and obesity might depend on, for instance, urban or rural residence, socioeconomic status, ethnicity or the geographical area where people live and their nutritional status in the first 1000 days of life. This report intends to assist policy-makers in the World Health Organization (WHO) Western Pacific Region by contributing to a better understanding of the unequal distribution of overweight and obesity in the Region, and by providing policy options to address the social determinants of overweight and obesity. Identifying vulnerable population groups or areas can help policymakers, programme managers and other actors to improve programme targeting and increase the effectiveness and improve the health and well-being of the most vulnerable.