Fighting obesity

Obesity is no longer just an American problem. The UK House of Commons Health Committee issued its report on obesity on 27 May 2004 predicting that obesity would soon overtake smoking as the leading health problem in the United Kingdom.¹ Throughout Europe, obesity has increased 10-50% within the past decade and by as much as 75% in parts of the developing world.² Worldwide over a billion adults and children are overweight,³ and some experts have predicted that the current generation of children are likely to have shorter life expectancies than their parents because of obesity.¹

Experts agree that the causes of the obesity epidemic are environmental, related to living in surroundings that allow easy access to food and little need for exercise. To date most approaches to obesity have focused on changing the behaviour of individuals—on diet and exercise—and cumulatively these have had little or no impact on the increasing prevalence of obesity. The report by the health committee is the first to describe a comprehensive and integrated strategy that emphasises the environmental contributors to the obesity problem. Unlike policies in the United States, which promote individual rather than state responsibility for the obesity problem, the strategy in the United Kingdom specifically states that the solution does not lie with the individual or doctor's office. The United Kingdom report recommends measures including the simpler labelling of food with red, yellow, and green symbols (categorising healthfulness) and banning vending machines and school sponsorships by companies associated with unhealthy foods, and better access to programmes to treat obesity. The report was critical of the British government, essentially describing current initiatives to tackle obesity as much talk but little action.

Both this report by the health committee and the World Health Organization's recent global strategy on diet, physical activity, and health have implicated the marketing of junk foods as an important cause of obesity, but they propose different solutions. WHO called for immediate bans on the advertising of unhealthy foods to children and restrictions on sugar content. The recommendations were criticised for not being evidence based allowing officials of the food industry to stall the plan.

A remarkable feature of the health committee's report is its call for the voluntary participation of the food industry in anti-obesity initiatives. The plan represents a willingness of the government to take corporate executives at their word, at least temporarily, to believe they are interested in the health of consumers. Members of the health committee state rightly that an approach using incentives instead of legislated restrictions may produce results faster and yield more creative solutions.

The report's recommendations are necessary and sensible but are not based on evidence of effectiveness.⁴ Few strategies for obesity have been proved to work. The only interventions that are well supported by research are surgery for the morbidly obese; drugs; and multicomponent weight loss programmes consisting of diet, exercise, and behaviour therapy.⁵ These studies have been done in clinical settings with adults and, with the exception of surgery, have resulted in only modest weight loss in the long term.⁵ More limited research on the prevention and treatment of obesity in children suggests that school based programmes may be effective.^6-8 Almost no data exist on the effectiveness of public health initiatives.

The lack of evidence does not condone inaction or delay. On the contrary, we must create the evidence. Adopted policies need to be tested scientifically, in well designed controlled studies, in order to evaluate and document the usefulness of each tactic. The many recommendations made by the health committee are idealistic and expensive. Funding limitations will require us to choose among proposals. Thus finding the most successful and cost effective policies will be crucial. As suggested in the report, when each initiative is implemented, a parallel process of evaluating its impact must be put into place.

Much research on obesity is hampered by our inability to measure food intake and energy expenditure accurately.⁶ Even more than in clinical studies, health policy research in obesity depends on reliable assessments of caloric intake and physical activity to assess the effects of interventions among large groups of people.

Inevitably the interest of the government and the public to support health will collide with the food industry's desire for profit if not immediately then soon. When such conflicts arise, the winning argument will be the one that can prove with hard evidence that their strategy works to combat obesity and promote health.