Global progress towards tackling obesity has been "unacceptably slow", with only one in four countries implementing a policy on healthy eating up to 2010, suggests a major new six-part Series on Obesity.
The research looks at how countries around the world are dealing with an increasing obesity epidemic, focusing on a range of issues from quality of diet to how children could be encouraged to eat healthier food.
It has been estimated that 600 million people worldwide are obese, with 2.1 billion now overweight. Being overweight has been believed to cause the deaths of 2.8 million people every year.
In low- and middle-income countries, stunting still affects over a fifth of children under 5 years of age, but obesity has been rapidly rising, creating a double nutritional burden that can affect the same population and the same individual, for example poorly-nourished infants who do not develop their full height but do gain more than their full weight.
This highlights the importance of ensuring a supply of food that encourages healthy growth, and that is not jeopardized by the aggressive marketing of cheap, less nutritious products by multinational food companies.
Experts are now calling for a worldwide action plan including restrictions on how food aimed at children is marketed.
They also want regulation of food nutritional quality and availability in schools, better labeling with nutritional values and taxes on drinks that are high in sugar.
The study is published in The Lancet.