The notion that obesity is mostly a matter of personal responsibility that’s best addressed through individual initiative takes a major blow this evening with the online publication of report on the international obesity crisis in the British medical journal The Lancet.

The four-part series by a number of international public health experts argues that the global obesity crisis will continue to grow worse and add substantial burdens to health-care systems and economies unless governments, international agencies and other major institutions take action to monitor, prevent and control the problem.

The series, which had support from the federal government and foundations, is published in advance of the first High-Level Meeting of the United Nations General Assembly focused on non-communicable disease prevention and control, which will take place in New York City Sept. 19 and 20.

Obesity is the result of people responding normally to the obesogenic environments they find themselves in. Support for individuals to counteract obesogenic environments will continue to be important, but the priority should be for policies to reverse the obesogenic nature of these environments.

If such actions not be taken, and if the current trends continue, half of all adults in the U.S. will be obese by 2030, the report says. (Currently 32 percent are obese, with BMIs of 30 or higher.) That will cause increases in the number of people who have -- and will require expensive treatment for -- such chronic conditions as cardiovascular disease, type 2 diabetes and cancer, the report says.

One of the four papers focuses on the need to rethink the common weight-loss wisdom that reducing calorie intake by 2 MJ [about 500 calories] per day “will result in slow and steady weight loss of about 0.5 kg [about a pound] per week.” That “ubiquitous” and “erroneous” rule doesn’t take into account the way the body adapts to weight loss. In particular, as anyone who has actually lost weight can attest, the less you weigh, the fewer calories you can consume if you wish to lose more weight or maintain weight loss.

The report proposes instead a new “approximate rule of thumb for an average overweight adult: every change of energy intake of 100 kJ [about 24 calories] per day will lead to an eventual bodyweight change of about 1 kg [just over 2 pounds]... with half of the weight change being achieved in about 1 year and 95 percent of the weight change in about 3 years.” Getting that straight will help in a lot of ways, including allowing for better planning and modeling of programs to address obesity.

Governments have largely abdicated the responsibility for addressing obesity to individuals, the private sector, and non-governmental [organizations], yet the obesity epidemic will not be reversed without government leadership, regulation, and investment in programmes, monitoring, and research.