The first paper in The Lancet Obesity Series describes the global initiators of the obesity epidemic according to a study by Professor Boyd Swinburn and Dr Gary Sacks from the WHO Collaborating Centre for Obesity at Deakin University in Melbourne, Australia.

The increase of obesity (defined by a body-mass index (BMI) greater than 30kg/m2) is worldwide, however rates vary widely between countries; whereas in Japan and China only 1 in 20 adult women is obese, in the Netherlands 1 in 10 women are grossly overweight compared to 1 in 4 in the UK and Australia, 1 in 3 in the USA, and a staggering 7 in 10 women in Tonga.

The steady rise in the apparent food consumption per capita in high-income countries in the 70’s and 80’s seems to be associated with the simultaneous start of the obesity epidemic. During the first half of the 20th century there was a matching decrease in apparent food consumption per capita that prevented a rise in obesity, despite people carrying out less physical work and starting to use more cars compared with the earlier 20th century.

Obesity is now encompassing all low- and middle-income countries obstructing their development, with many countries facing a double-burden of obesity-related chronic disease and under-nutrition in others.

It affects both sexes and all ages in high-income countries but is more common in poorer people compared to lower-income nations, where obesity seems to be more widespread in middle-aged adults, especially women from wealthy urban environments.

The mission for effective obesity strategies carries on, even though some countries successfully managed to keep tobacco consumption, high blood pressure and heart disease under control.

According to the authors, there is “no country, that can act as a public health exemplar for reduction of obesity and type 2 diabetes.”

1.5 billion adults worldwide are overweight and a further 0.5 billion are obese; 170 million children are classed as either overweight or obese. In many countries, obesity claims between 2% and 6 % of health-care costs and has surpassed tobacco as the largest preventable cause of disease in regions such as the USA and the state of Western Australia. Encouraging reports emerging from countries like Australia, Sweden, France and elsewhere state that obesity rates in children are levelling off or falling.

The researchers point out that, considering the magnitude of the problem, surprisingly most countries seem to possess unsatisfactory systems for monitoring population weight and nutrition.

The main causes of the obesity epidemic are increased supply of cheap, tasty, energy-dense food, improved food distribution and marketing coupled with strong economic forces driving consumption and growth.

Built environmental factors also affect the driving forces for obesity by modifying the effects. In the Netherlands for example, obesity rates are rising slower than in the USA because of the country’s highly active transport culture (cycling) compared to the USA, where most people use their cars extensively.

Environmental factors that affect gene expression (epigenetic factors) are a key area of current research that may explain the high variability in obesity rates between individuals.

Even though it is apparent that individual choices are key drivers for someone’s tendency to become overweight, the author highlights that people have to consider the complexity of their environment and its choices, although many of these decisions are subconscious and the individual is unaware of them.

According to the authors, the most effective interventions for reversing the obesogenic drivers will mainly be though government policy, for example by shifting agricultural polices to incorporate health outcomes, banning unhealthy food marketing to children, healthy public sector food service policies etc.

The food industry could also assist by introducing policies to move product formulation towards healthier compositions and self-regulation of marketing to children for example.

Compared with health education and promotion programs, environmental policy-led solutions have several strengths as they tend to be sustainable, affecting the whole population including those difficult to reach, become universal by affecting default behaviors and can reverse some of the environmental drivers. However, the bureaucratic problematic to implement policy and regulatory interventions is generally much more complicated than that for program- and education-based interventions. One of the reasons for this is continued lobbying against possible future policies by the powerful food industry, as well as people’s own reluctance to sacrifice certain comforts they have grown accustomed to, for example car access, cheap parking, and purchasing tasty but unhealthy foods to name but a few.

The authors also argue that, despite many benefits to current government policies that promote economic growth and free trade, these policies contribute to the global crises of over-consumption, including obesity and climate change. They maintain their opinion for the need of a new framework that promotes prosperity in a broadly defined way, including economic, social, health, and environmental aspects.

Although conversion of national obesity action plans have been generally poor until now, the authors note some positive points for the future, including the UK’s cross government strategy for obesity, marketing restrictions, and improving school food; and also the US White House Task Force on Childhood Obesity, championed by US First Lady Michelle Obama.

With regard to the UN Member States meeting in September for the first ever UN High-Level summit on non-communicable diseases (NCDs), the authors add that, “the inexorable global rise of obesity will be the toughest challenge that they face.”

Written by Petra Rattue