What should we do about overweight and obesity? The goals of treatment should not necessarily be to normalise weight, but to optimise health |
MJA 1999; 171: 599-600 | ||
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Introduction -
Why are we getting obese? -
Why have we not been effective in treating obesity? -
What should we do about obesity? -
What has been ignored is our environment
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| Introduction |
Obesity and overweight have always been with us, but they are now the
norm rather than the exception. Almost two-thirds of Australian men
and about half of Australian women are overweight (body mass index
[BMI] 25-29.9) or obese (BMI  30).1 Obesity in Australian
children appears to have doubled in recent years.1 Increasing
obesity is a worldwide phenomenon,2 and with it comes an increase
in obesity-related metabolic disease, such as type 2 diabetes,
dyslipidaemia, hypertension and ischaemic heart disease. In
Australia the health costs of obesity and its associated diseases
have been estimated to be some $830 million.3 This figure ignores the
intangible costs due to premature death, the effects of obesity on
quality of life and the amount spent on weight loss programs (more than
$500 million).
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Why are we getting obese? | |||
| In this issue of the Journal, several articles allude to contributing causes: the genetic basis of obesity, (over)abundance of food, and our technological society with its emphasis on labour-saving devices, efficiency and time saving. We are less active in our everyday lives; it is not just that we are not exercising, but that the incidental activity of everyday life has been reduced or eliminated by technological advances. We don't walk as much, or as far, and we don't expend as much energy operating machinery or manual tools. Consequently, it has proved very difficult for many people to control their weight in the second half of the 20th century. | |||
Why have we not been effective in treating obesity? | |||
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There are a number of reasons for this. Obesity, its aetiology and
effects, the biology of adipose tissue (which is not just an inert
storage organ) and goals of treatment have been poorly understood.
Nutrition has not been considered an important part of the medical
curriculum. No long term effective medical treatments have been
available. Finally, as Dupen et al show, only 6% of
the articles in medical publications discuss physical
activity,4 so it is little wonder that
this effective medical and public health approach is ignored in
favour of other programs or pharmacological therapy. Governments,
our own included, are now promoting greater physical activity
because of the impact of sedentary lifestyle on health.5,6
Despite the lack of real assistance from the medical profession, the obese have been stigmatised.7 Obese patients have become disheartened after their attempts at weight loss. They have turned to other treatments and therapists, mostly without success. The results of therapy with some of the more recent, and less outlandish, therapies are reviewed by Egger et al 8 in this issue of the Journal. The vast majority of these treatments, some costly, are ineffective. Patients are still looking for the magic which will enable them to lose weight without effort and then to keep it off. | |||
What should we do about obesity? | |||
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Two major options are discussed in articles in this issue of the
Journal. Burry argues that weight loss and control
must remain an individual responsibility,9 whereas Proietto argues that in some individuals morbid obesity is
inevitable because of their genes, inherent appetite drives and
metabolic setpoints, and that they will inevitably need
pharmacological help to control weight.10
These are not really exclusive categories; both approaches are correct in part and do have a place. Some individuals with higher BMIs (possibly > 35) will have genetic causes of their obesity; some of those who are overweight should be able to control their weight by taking responsibility for their lifestyle; but there are also those who need both lifestyle alteration and adjunctive therapy. Medical practitioners must judge what combination of therapy and behavioural change would benefit each patient. A supportive, knowledgeable medical environment in which individuals can be helped to understand what is necessary in the way of food intake and daily activity is vital. When lifestyle changes are not enough, or in the presence of metabolic disease, an appropriate medical treatment should be added.2 The goals of such treatment should not necessarily be to normalise body weight, but to optimise health. A reduction of 6-10 kg can significantly decrease the cardiovascular health risks of overweight or obese people.11 There are new drugs which capitalise on the increasing knowledge of the physiology and pathophysiology of body weight and which help achieve and maintain this degree of weight loss. Two available outside Australia are orlistat, a pancreatic lipase inhibitor which reduces fat absorption by 30%,12 and sibutramine, which has both noradrenergic and serotonergic effects acting on appetite and thermogenesis.13 Some of the other drugs in development that may alter energy expenditure or central appetite control pathways include leptin derivatives, thermogenic agents and neuropeptide Y antagonists. | |||
What has been ignored is our environment | |||
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We accept that we can change the environment when (for example)
building developments, second airports, smoking and recycling are
concerned, but we abrogate responsibility for many healthy
lifestyle issues, including the prevention of obesity. The recent
increase in obesity can be attributed to environmental change, as our
genes haven't changed. Therefore, we need to change our environment
to prevent obesity.
Health education alone hasn't been enough to impede the increase in obesity. We can make it easier and safer for Australians to be more active. We can ensure that all Australians get access to cheap, fresh, healthy foods. We can ensure our children have the opportunity to be fit and healthy. The type of environmental change necessary is not the "micro-environmental" change by individuals or in homes, but rather "macro-environmental" changes which involve governments, policies, planning, business and health professionals.14 Such changes involve urban planning, transport, roads, and food production and distribution. Workplaces and schools must be involved. We need to plan for a healthy environment that encourages and makes activity possible and which delivers cheap, healthy food to all. It is important to make a distinction in types of activity. While some may choose to become physically active (eg, jog, or play sport) what we wish to encourage and increase is "incidental activity". This means more activity in our daily lives, coupled with opportunity to do even more physical activity by individual choice. Examples might be providing bike tracks, or measures to increase the amount of walking required by commuters (by moving car parks, increasing the use of public transport, or replacing lifts and escalators with ramps and stairs). We may need to look critically at some labour-saving devices and promote the health benefits of manually powered devices. The aim is not to make everyone thin, but to prevent some becoming overweight or obese. A mean weight loss of 1 kg in the Australian population would have a major impact on health. We actually have a plan to attempt this.3 It requires intersectoral cooperation between government departments (not just health departments), non-government organisations, local government, health professionals and the community. Rather than insisting that weight control is an individual responsibility, medical practitioners can take the lead in altering the environment and educating and involving those who can. Ian D Caterson
©MJA 1999
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