Citizens of the world have been given a gloomy and worrying health warning – half of us will be classed as obese or overweight by 2035. The World Obesity Federation (WOF) has warned that in just over a decade, more than four billion people will be too heavy for their own well-being. There are currently over a billion obese people in the world. The fastest rising rates are among children and adolescents. The WHO defines obesity as "abnormal or excessive fat accumulation that presents a risk to health". A body mass index (BMI) over 25 is considered overweight, and over 30 is obese. In June 2013, the American Medical Association classified obesity as a disease. Many health organizations have described it as a pandemic.

The WOF warned immediate action must be taken to avoid "serious repercussions" in the future. It said the rise was "particularly worrying". It added that, "governments and policymakers around the world need to do all they can to avoid passing health, social, and economic costs on to the younger generation". The federation called for the root causes to be addressed. These include an increased consumption of highly processed foods, greater levels of sedentary behaviour, and a lack of healthcare services to assist in weight management. The WOF recommended restricting the marketing of food that has high fat, salt or sugar content, and providing healthy food in schools.