Obesity series exposes 'unacceptably slow' progress in tackling soaring global obesity rates over last decade

In less than a generation, rates of child obesity have risen dramatically worldwide. For example, in the USA children weigh on average 5kg 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 US children are consuming an average of 200kcal per day more than they were in the 1970s, and that this is $400-worth of food per child per year, or $20bn a year for the US food industry. "Fat children are an investment in future sales," says 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 jeopardised by the aggressive marketing of cheap, less nutritious products by multinational food companies, say the Series authors.

"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," adds 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 recognise that today's food environments exploit people's biological (eg, innate preference for sweetened foods), psychological (eg, marketing techniques), and social and economic (eg, convenience and cost) vulnerabilities, making it easier for them to eat unhealthy foods," explains Dr Christina Roberto, from the Harvard T.H. Chan School of Public Health, USA.

"It's time to realise 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. Examples include: tighter supervision and international regulation of the food supply; an international code of food marketing to protect children's health; regulating food nutritional quality in schools along with programmes to encourage healthy food preferences; taxes on unhealthy products such as sweetened drinks and subsidies on healthier foods for low-income families such as vouchers for fruit and vegetable boxes; and mandatory food labelling as an incentive for industry to produce more nutritional products.

However, the responsibility for reducing the prevalence of obesity goes far beyond governments, say 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 UK, and access to health care granted to all people living with HIV/AIDs in South Africa.

Finally, say the authors, health professionals are poorly prepared to treat obesity. More must be done to improve health-care 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.

According to Series lead Professor Boyd Swinburn from the University of Auckland, New Zealand, "The key to meeting WHO's target to achieve no further increase in obesity rates by 2025 will be strengthening accountability systems to support government leadership, constraining the role of the food industry in the formation of public policy, and encouraging civil society to create a demand for healthy food environments."

The Series is published ahead of presentation at the Healthy Eating Research 9^th Annual Grantee Meeting in Baltimore, USA, on Thursday 19 February. The Series can be found online at: http://www.thelancet.com/series/obesity-2015