The US estimate is based on actual health examinations, while data from most other countries are from self-reporting health surveys. Comparable data from health interview surveys show a lower US figure, though still at 22% in 1999. Similarly, for Australia, the obesity rate based on health examinations conducted in 1999 was 21%, but 18% based on self-reported survey data in 2001.
Still, the outcomes point to a pressing problem. In Australia, obesity has more than doubled and in the United Kingdom the rate has tripled over the last 20 years, based consistently on health examination measures in the two countries. More than 20% of the adult population in Australia and the United Kingdom are now defined as obese, the same rate as in the United States ten years ago. By contrast, the obesity rates in Denmark, Sweden and Norway, as well as France, Italy, the Netherlands and Switzerland remain in the 10% area, according to self-reported data, though obesity rates in these countries have begun to rise.
Obesity is a known risk factor for several disorders, such as diabetes, hypertension, cardiovascular diseases, respiratory problems (asthma) and musculoskeletal diseases (arthritis). It has several causes, too, including excessive calorie consumption, lack of physical activity, genetic predisposition and disorders of the endocrine system of glands that produces the hormones necessary for normal bodily functions, like metabolism and growth.
Culture and environment also influence obesity, like dietary customs or the working environment. A recent study by Lawrence Frank, associate professor of urban planning at the University of British Columbia, even suggests urban sprawl as being a possible factor, as in the suburbs, people tend to drive more and walk less.
The economic and non-economic consequences of obesity are vast. In the United States, a recent study by Roland Sturm looked at the consequences of obesity on medical problems such as diabetes and asthma and related costs, and compared them with other risk factors, like smoking and alcohol consumption (see references). The study found that obesity has the same association with chronic health conditions as does 20 years of ageing, greatly exceeding the association of smoking or excessive drinking for those conditions studied.
It was estimated that obesity is associated with an even higher average health cost increase per year than costs related to smoking. So much so, in fact, that in the US a group of large employers, headed by Ford Motor, Honeywell, General Mills and PepsiCo, announced a campaign this June to encourage overweight workers to slim down as a way to improve both their personal health and the corporate bottom line. Dr Vince Kerr, director of health care management at Ford, says weight-related costs are adding US$12 billion per year to costs of employers across the United States.
One worrying feature for places like Australia and the UK, where obesity has risen since 1980, is that there is a time lag between the onset of obesity and related disorders, suggesting that health problems (and costs) are being stored for the future.
Diet changes and physical exercise can help tackle obesity, although this is easier said than done, particularly as behavioural and environmental barriers are at play. Apart from promoting a healthy lifestyle, preventing obesity in childhood is perhaps a more effective approach in the long term. Effective family-based and school-based programmes can help. So might the law, with several legal battles now being waged against manufacturers and distributors of foods that are accused of contributing to obesity. Other food companies are taking initiatives themselves, with food giant Kraft announcing at the start of July its plan to cut fat and sugar content in its foods.
Ebbeling, C. et al (2002), “Childhood obesity: Public-health crisis, common sense cure”, The Lancet, Vol. 360, Issue 9331, 10 August 2002.
Seelye, K. (2003), “Cities Made for Walking May Be Fat Burners”, The New York Times, 21 June 2003.
Sturm, R. (2002), “The Effects of Obesity, Smoking, and Drinking on Medical Problems and Costs”, Health Affairs, Volume 21, Number 2, March/April 2002.
WHO (1997), Obesity: Preventing and Managing the Global Epidemic, Geneva (see link below).
©OECD Observer No 238, July 2003