Overweight and obesity are the fifth leading cause of death globally. Poverty and socioeconomic status (SES) determine child weight. The global burden of underweight associated with absolute poverty is reducing and the issue of overweight dramatically growing. Prevalence of overweight and obesity in developed countries is higher than in developing countries, although, in absolute values there are more overweight and obese children in developing countries. Predominantly, higher SES in developing countries and lower SES in developed countries lead to increased risk of overweight and obesity. These trends are complex and not always unidirectional and linear, there are many intertwining influencing factors. Neighbourhood SES and individual demographics determine weight status. Parental income and education determine weight status as well as stress, negative life events and ethnicity. Place of residence effects weight status also; urban poor in developing countries and rural poor in developed countries have higher risk of overweight than their counterparts, the rural poor in developing countries and urban poor in developed countries. Generally, how SES effects weight depends on the equity and socioeconomic development of the country. In developing countries, the rich lavish their children with the novel westernised diet and may be naïve of the dangers of the newly adapted sedentary lifestyle. The developing country poor are catching up with the lifestyle behaviours of the rich as they urbanise and lose the capacity to farm their own healthy and natural food and remain the physically active lifestyle of traditional rural life. The developed country poor struggle to afford healthy diets and expensive sport hobbies and are uneducated in the requirements of a healthy lifestyle. It is only those of high SES in developed countries who have the awareness and means to keep their children physically active with a nutritional and balanced diet and so reduce their risk of overweight. Unsurprisingly, as developing countries progress, their trends in weight status see a transition towards the trends of developed countries. Action in the form of promoting healthy eating and physical activity are required to reduce such inequalities in health, education and lifestyle to decrease the global burden of overweight and obesity.