HEALTH / Second opinion

PEOPLE in Britain, and most other countries, are getting fatter. The proportion of the British population defined as obese has almost doubled since 1981 and is now around one in eight adults: among those over the age of 50 it is close to one in five.

The definition of obesity is a technical one: the internationally accepted measure, the Quetelet index, is obtained by dividing the weight in kilograms by the square of the height in metres; if the figure is over

30, the individual is judged to be obese. This is roughly the same as someone being 20 per cent above the standard weight for their height.

Being seriously overweight is damaging to health: the undisputed effects include an increased risk of heart disease, high blood pressure, diabetes, arthritis, and several common cancers. The overweight also suffer socially and economically. Yet in a recent issue of the British Medical Journal a case was advanced that doctors should not be trying to treat obesity.

The argument set out by Professor Susan Wooley and Dr David Garner, two research workers in the United States, is a practical one. More than 90 per cent of overweight people who lose weight regain it within a few years. Repeated cycles of losing and regaining weight are bad for health: research studies have shown that people whose weight fluctuates in this way die sooner than those who are consistently overweight.

Furthermore, treating people who are overweight implies that they have something wrong with them, and when the treatment fails the unsuccessful dieter may feel an unhealthy failure. This loss of self-esteem is, say the American authors, illogical and unfair: the treatment, rather than the patient, is at fault. 'We should stop offering ineffective treatments aimed at weight loss. Researchers who think they have invented a better mousetrap should test it in controlled research before setting out their bait for the whole population. Only by admitting that our treatments do not work - and showing that we mean it by refraining from offering them - can we begin to undo a century of recruiting fat people for failure.'

Obese patients should continue to be counselled to eat a balanced, healthy diet and to take exercise; they should be treated for disorders such as binge eating. They should be helped to deal with the social and emotional implications of remaining fat, and to improve their body image - but they should be protected from being blamed for their condition.

This argument is rejected by orthodox nutritionists. Professor John Garrow of London's St Bartholomew's Hospital agrees that the treatment given to obese patients is often ineffective, but says this does not justify abandoning all attempts to treat it. Professor Garrow recommends a combined approach. First, the Health Education Authority should publicise the level at which being overweight becomes a medical rather than a cosmetic problem - at a Quetelet index somewhere between 25 and 30. Second, he says the treatment for overweight people should be based on self-financing but non-profitmaking slimming groups led by registered dieticians. The objective should be to help people lose 0.5-1kg (1 - 2lb) per week through a combination of eating less and taking more exercise.

Too much that is written and broadcast about

obesity is misleading and mischievous, Professor Garrow argues. Claims are made that obesity is not really a health hazard, that dieting is doomed to failure because of subtle changes within the body - or that weight can easily be lost without dieting by means of some magic pill or potion. The more persuasively

arguments are advanced that obesity cannot be treated or should not be treated, Garrow says, the more difficult it becomes to tackle.