The effects of excess body weight on morbidity and mortality have been known since the time of Hippocrates, who said that that sudden death is more common in those who are naturally fat than in the lean (1,2). However, a Department of Health Study found that in the UK in the period 1980-91 adult obesity had doubled from 6 to 13% in men, and from 8 to 17% in women.(2)

The condition has a complex multifactorial aetiology including excess calorie intake, decreased physical exercise, psychological factors, socio-economic forces and metabolic and endocrine abnormalities. It has been suggested that socioeconomic factors such as social class and level of education are equal to or even greater determinants of obesity than inherited abnormalities of metabolism.(2)

In order to improve the health and well-being of those whose health is compromised by obesity, sustainable lifestyle changes are required. Short term changes in dietary intake and exercise levels may lead to short term improvement but the person remains vulnerable to a return to their former eating and exercise patterns 

and all the benefits achieved are likely to be lost again. Furthermore, a person's health risks may actually be increased by a process of weight cycling (weight loss, weight gain, weight loss, weight gain etc). It is not helpful simply to provide a person with a diet sheet and this may be actually unhelpful. The person needs to be helped to change their behaviour in a sustainable way.

Obesity is a condition that may not respond to conventional methods of treatment: its management may require an approach that is tailored to an individuals need. The ability of a treatment to maintain long-term weight reduction is as important as its ability to cause the initial weight loss.(3)

Morbidity and Health Care Costs Associated with Obesity

It is important to recognise that with very few exceptions, obesity per se is not a medical problem. However obesity has been implicated as a significant predisposing risk factor in a variety of disabling and life-threatening conditionsf2)

In the UK the Office of Health Economics has estimated the cost of obesity itself at more than £30m per year, and the cost of associated diseases at about £165m per year. A large increase in costs associated with obesity can be expected if prevalence trends continue (2).

Being overweight increases the risk of developing many common diseases including non-insulin dependent diabetes mellitus, hypertension, coronary heart disease, gallstones and various cancers of the gastrointestinal and urogenital tracts. It can also cause or exacerbate osteoarthritis, breathlessness, heartburn, sleep apnoea, venous thromboembolism and psychological distress, particularly anxiety and depression. It makes anaesthesia and surgery more hazardous and in pregnancy increases risks associated with childbirth. Being overweight can also complicate day-to-day social functioning such as negotiating seats on public transport or purchasing clothes (2,4,5) However, there is little published data on the long-term effects of weight loss on hard endpoints such as myocardial infarction, strokes or diabetes.(2)

This document will not deal with the prevention of obesity or managing obesity in childhood although it is recognised that these are major issues. This guideline aims to provide practical advice on the day to day management of obesity in adults in general practice.

Objectives of treatment

The objectives of treatment have been defined (3) and include: