Wednesday May 26 2010
Remaining active is important for many aspects of people's health
A lack of exercise is “worse for health than being obese”, The Daily Telegraph has reported. It quotes an expert as saying that lack of fitness is the root cause of more illness than excess body fat.
The Telegraph’s story is based on one of a pair of opinion pieces by medical experts with opposing views about how to improve public health and reduce the risk of major health problems, such as diabetes and stroke. One article argues that health policy should focus purely on increasing people’s physical activity rather than worrying about weight loss. The other article maintains that treatment to prevent and reduce obesity is crucial, and that radical changes to diet and lifestyle are needed.
The Telegraph’s story emphasises the view that physical activity needs to be encouraged, but the newspaper only gives a cursory mention to the other viewpoint that reducing obesity should be given priority. Together, these arguments illustrate the dilemma behind forming public health policy, but they do not diminish the fact that staying active and eating healthily are both important health goals for individuals to pursue.
Where did the story come from?
The news comes from a pair of opinion-based pieces debating the priorities for public health policies:
- The first is by Dr Richard Weiler, a specialist registrar in sport and exercise medicine at Charing Cross Hospital, London, and colleagues. He argues that health policy should focus on fitness rather than fatness.
- The second is by Associate Professor Timothy Gill, principal research fellow at the Boden Institute of Obesity, Nutrition and Exercise, University of Sydney, and colleagues. He argues that health policy should focus on fatness rather than fitness.
The opinion pieces were both published in the same issue of the peer-reviewed British Medical Journal.
What kind of research was this?
The two papers were a ‘head to head’ feature, in which two experts in the field put forward their opposing opinions about a topical issue. In this case, the issue was whether health policy should focus purely on reducing physical inactivity or target the prevention and treatment of obesity.
Both sets of experts discussed their professional opinions and experiences, supporting these views by referencing relevant medical literature.
What evidence was presented?
In the first paper, Dr Weiler argues that improving physical activity is associated with improvements in health, even if no weight is lost. A lack of physical activity presents “one of the greatest health threats facing developed nations today”, he believes, particularly given that 95% of the UK population does not achieve recommended amounts.
To support his view, he cites several large cohort studies, which found that physical inactivity, rather than obesity, is the cause of many major life-threatening disorders, including cardiovascular disease, diabetes, dementia, stroke, mental health problems and cancer. He draws particular attention to one synthesis of systematic reviews, which has found that physically active people have a reduced risk of many of these disorders.
Dr Weiler goes on to cite evidence that cardiovascular fitness, which is developed and maintained by regular physical activity, is a better predictor of mortality than obesity. He also cites a Scottish Health Survey, which found that even when body mass index is taken into account, all types of physical activity are linked to reduced mortality.
He also argues that drugs and bariatric surgery for obesity, which are now becoming more commonly used, have serious risks and do not have the same health benefits as physical activity. Dr Weiler also cites a report suggesting that since the 1980s we have become less active because of our environment. Policy makers, he argues, should look at changing our built environment, patterns of land use and transport infrastructure in order to encourage greater physical activity.
In the second paper, Professor Gill argues that although the promotion of physical activity is important, ignoring the problem of obesity and poor diet is unlikely to bring overall improvements in health. To that end, he argues that physical inactivity is just one marker of a society’s overall “obesogenic lifestyle”. He cites a report from the World Health Organization in 2003, which he says examined a wide range of evidence and identified poor-quality nutrition as a major contributor to obesity and other health problems, such as tooth decay, high blood pressure and various cancers.
He also cites evidence that the health risks of obesity are associated with more severe chronic disease and early death. He believes that physical activity alone, while able to reverse some of these negative health consequences, is not enough to counteract all of them.
Professor Gill says that people who are obese need access to high-quality treatment and well-trained professionals, but that obesity services and management are often under-resourced. He says that although previous programmes on obesity have had limited success, there is now evidence, including systematic reviews, that small group- and community-based lifestyle programmes can be effective.
Professor Gill also further emphasises the need for improved urban planning – for example, more cycle lanes, improved public transport and increased access to green space. But he also advocates changes in local food production and food pricing strategies as a way of encouraging healthier eating.
What conclusions did the authors make?
Dr Weiler concludes that for health policy to focus on weight loss is “largely misleading” and that undesirable health risks can be greatly reduced by increasing physical activity, which leads to improved fitness, even in the absence of weight loss.
Professor Gill says that a focus on reducing obesity through a broad range of actions, including diet and behavioural issues, is likely to be more effective than focusing solely on reducing physical inactivity.
Interestingly, both specialists agree that there is a need for wider programmes to improve the environment and encourage changes in behaviour.
The issue of physical inactivity and obesity are both major public health problems, which policymakers and professionals must work hard to address. This pair of “head to head” articles is a valuable contribution to the debate over how best to tackle the overlapping problems of obesity and inactivity. Both authors write convincingly about the subject, and both cite good evidence to support their opinions as to how the problems should be addressed. This debate highlights the difficulty in agreeing on the best approach to public health problems, particularly when there is good evidence for different policies.
Both authors agree that reducing the risk factors for major illnesses, such as cardiovascular disease, cancer and diabetes is crucial to public health, although they disagree about whether the emphasis should be on physical activity alone or whether it should include the prevention and treatment of obesity. They both agree that the wider environment needs to change in order to encourage individual behavioural change.
It is also important to note that this debate is about the merits of different health policies and how best to allocate finite health resources. The articles are not intended to offer advice on individual behaviour or to decide whether a person’s inactivity poses a greater or lesser risk than their obesity. Indeed, there is no reason why individuals cannot tackle both problems by adopting a healthy diet, maintaining a healthy weight and getting 30 minutes of moderate-intensity physical activity every day.