Global progress toward tackling obesity has been “unacceptably slow,” with only one in four countries implementing a policy on healthy eating up to 2010, according to a major six-part Series on obesity, published in The Lancet.

In less than a generation, rates of child obesity have risen dramatically worldwide. For example, in the U.S., children weigh on average 5 kg more than they did 30 years ago, and one in three children is now overweight or obese. Although child obesity rates have started to level off in some cities and countries, no country to date has experienced declining rates of obesity across its population.

New estimates produced for the Series suggest that U.S. children are consuming an average of 200 kcal per day more than they were in the 1970s, and that this is $400-worth of food per child per year, or $20 billion a year for the U.S. food industry. “Fat children are an investment in future sales,” said Series co-author Dr. Tim Lobstein, from the World Obesity Federation.

In low- and middle-income countries, stunting still affects over a fifth of children under 5 years of age, but obesity is 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, the Series authors said.

“Undernutrition and overnutrition actually have many common drivers and solutions, so we now need to see an integrated nutrition policy that tackles both these issues together,” added Dr. Lobstein.

The food industry has a special interest in targeting children. Repeated exposure to highly processed foods and sweetened drinks during infancy builds taste preferences, brand loyalty and high profits. This year the global market for processed infant foods is expected to be worth a staggering $19 billion, up from $13.7 billion in 2007. Yet, few countries have taken regulatory steps to protect children from the negative health effects of obesity or implemented widely-recommended healthy food policies. Most have relied solely on voluntary moves by the food industry, with no evidence of their effectiveness.

“Our understanding of obesity must be completely reframed if we are to halt and reverse the global obesity epidemic. On one hand, we need to acknowledge that individuals bear some responsibility for their health, and on the other hand recognize that today’s food environments exploit people’s biological (e.g., innate preference for sweetened foods), psychological (e.g., marketing techniques), and social and economic (e.g., convenience and cost) vulnerabilities, making it easier for them to eat unhealthy foods,” explained Dr. Christina Roberto, from the Harvard T.H. Chan School of Public Health, USA.

“It’s time to realize that this vicious cycle of supply and demand for unhealthy foods can be broken with ‘smart food policies’ by governments alongside joint efforts from industry and civil society to create healthier food systems.”

The Series authors call for food policies that change the nature of the food and consumer environment including the availability, price, and nutrition standards of food products, and the marketing practices that influence food choices and preferences.

However, the responsibility for reducing the prevalence of obesity goes far beyond governments, said the Series authors. They make a number of hard-hitting recommendations for public health professionals and society, including the proposal that civil action is key to combating obesity. The authors point out that it was pressure from the public that saw smoking banned in public indoor places in the U.K., and access to healthcare granted to all people living with HIV/AIDs in South Africa.

Finally, the authors said, health professionals are poorly prepared to treat obesity. More must be done to improve healthcare training, particularly to address biases about patients with obesity, and to improve care-delivery strategies, specifically for children with obesity for whom there are currently few treatment options.