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REFERENCES Carey V J, Walters E E, Colditz G A et al. Body Fat Distribution and Risk of Non-insulin-dependent Diabetes Mellitus in Women: The Nurses’ Health Study. Am J Epidemiol 1997; 145: 614–19. Colditz G A, Willett W C, Rotnitzky A et al. Weight Gain as a Risk Factor for Clinical Diabetes Mellitus in Women. Ann Intern Med 1995; 122: 481–6. Davies R J, Stradling J R. The Relationship between Neck Circumference, Radiographic Pharyngeal Anatomy, and the Obstructive Sleep Apnoea Syndrome. Eur Respir J 1990; 3: 509–14. de la Maza M P, Estevez A, Bunout D et al. Ventricular Mass in Hypertensive and Normotensive Obese Subjects. Int J Obes Relat Metab Disord 1994; 18: 193–7. He J, Ogden L G, Bazzano L A et al. Risk Factors for Congestive Heart Failure in US Men and Women: NHANES I Epidemiologic Follow-up Study. Arch Intern Med 2001; 161: 996–1002. Manson J E, Willet W C, Stampfer M J. The Nurses’ Health Study: Body Weight and Mortality among Women. N Engl J Med 1997; 333: 677–85. Peeters A, Barendregt J J, Willekens F et al. Obesity in Adulthood and its Consequences for Life Expectancy: A Life-table Analysis. Ann Intern Med 2003; 138: 24–32. Young S Y, Gunzenhauser J D, Malone K E et al. Body Mass Index and Asthma in the Military Population of the Northwestern United States. Arch Intern Med 2001; 161: 1605–11.

Management of Obesity and Overweight M E J Lean

The emergence of obesity as a distinct disease presents new issues for health services, and often personal conflicts for doctors relating to the aims and potential demands of treatment. The justification for treating obesity is founded on its enormous cost to health services (including drugs for conditions resulting from weight gain) coupled with evidence of the benefits of weight loss. There is less well-documented evidence for benefits of weight loss than for the association between obesity and secondary diseases, partly as a consequence of the limited number of studies that have induced and maintained weight loss long enough to provide such data, and partly because uncritical dismissal of interventions that did not ‘cure’ obesity by achieving normal body weight. More recently, it has been recognized that modest weight loss leads to major long-term health gains, and the emphasis has shifted towards weight maintenance.

FURTHER READING Inoue S, Zimmet P. The Asia–Pacific Perspective: Redefining Obesity and its Treatment. Sydney: Health Communications Australia. www.diabetes.com.au/downloads/obesity_report.pdf (The epidemiology and health consequences of obesity in Asia.) National Institutes Of Health National Heart, Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. NIH Publication No. 98-4083 September 1998. Bethesda: National Institutes of Health, 1998. www.nhlbi.nih.gov/guidelines/obesity/ob_gdlns.pdf (This large, evidence-based report on obesity provides a wealth of information on all aspects of the disease.) Nature Insight 2000; 404. (An entire issue devoted to obesity, including medical aspects, genetics and treatment.) UK National Audit Office. Tackling Obesity in England. HC 220 Session 2000–2001: 15 February 2001. London: HMSO, 2001. www.nao.gov.uk/publications/nao_reports/00-01/0001220.pdf (Details the costs of obesity to the NHS and makes recommendations on initiatives across government to address the problem.)

Aims and criteria of success in weight management Most individuals gain weight gradually during adult life, reaching a plateau at about 60 years of age. The rate of weight gain varies; the average is 15–20 kg between age 20 and 60 years. In those who become obese, a gain of 1–2 kg/year is average and 5–10 kg/year is common. Only a few individuals maintain a body mass index (BMI) of less than 25 kg/m2 throughout their adult M E J Lean is Professor of Human Nutrition at the University of Glasgow, UK, and Honorary Consultant Physician at Glasgow Royal Infirmary.

What’s new ? • Adult obesity (BMI > 30 kg/m2) has exceeded the WHO definition of an epidemic (> 15% worldwide) • Correcting physical inactivity is increasingly seen as the vital first step in effective weight management • Weight loss of 5–10 kg sustained for 4 years by modest dietary change, moderate physical activity and orlistat reduces the incidence of diabetes by 30–60% • Long-term (2-year) trials of sibutramine and orlistat show sustained weight loss of about 12–13 kg, with improvements in all risk factors • Major weight loss after gastric surgery for obesity tends to be followed by regain after 2–3 years, but with sustained health benefits including prevention of diabetes

Practice points • Obesity reduces life expectancy by about 7 years in 40-year-old men and women • Obesity is an important risk factor for cardiovascular diseases including CHD, heart failure and stroke • Weight gain, obesity and a large waist circumference are potent predictors of later development of type 2 diabetes • Respiratory complications of obesity are common; sleep apnoea is predicted by neck circumference > 42 cm

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Indicators of success in weight management 35

BMI (kg/m2)

Improved diet and lifestyle to reduce risk factors 30

Intervention

f adult

urse o tural co

weight

gain

Reduced rate of weight gain

Na

No weight gain Modest weight loss followed by variable regain Weight normalization

25

20

Years of management with intermittent monitoring 1

life. The normal range, with the lowest risks of many problems, is 18.5–25 kg/m2. Although this might be ideal, it is an unattainable goal for most obese patients. Figure 1 shows possible criteria for success in weight management, taking as an example an intervention when the individual reaches a BMI of 25 kg/m2. Any reduction in the trajectory of adult weight gain may be considered a success. Remembering the powerful interaction between other risk factors and obesity, the first level of success should be a change in lifestyle to reduce other risk factors, even if weight gain is not modified. The success of any weight management programme must be evaluated over a relatively long period of time. Obesity-prone individuals often experience large fluctuations in body weight for social, personal and other reasons. Weight loss is usually short term and cannot be considered the sole criterion of success. It is inappropriate to initiate any treatment outside the context of a programme aimed at results in 12 months or more. On average, overweight and obese patients can lose weight for 3–4 months, but beyond this period it is unreasonable to seek further loss. Instead, it is more logical to concentrate on maintaining the lower weight or restricting weight gain in the future. Prevention of weight gain should always be the primary aim of management, because it represents a cure of obesity (defined as the disease process of excess fat accumulation with multiple organ-specific pathological consequences). Initial weight loss can be induced by a wide range of interventions, including simple dietetic advice and follow-up (Figure 2). In contrast, evidence for

the efficacy of treatment in maintaining a lower weight is limited. Surgical intervention (e.g. gastric bypass) is effective in about 90% of patients, and the small number of anti-obesity drug trials that have been prolonged beyond 1 year have been effective in most patients. Among behavioural, dietary and lifestyle interventions,

Weight management in primary care Public awareness campaign Waist > 94 cm in men, > 88 cm in women

Practice audit

Opportunistic

Recruitment Smoking

Lipids Symptom and risk factor management

Alcohol

Diabetes

Blood pressure BMI

> 30 kg/m2

25–30 kg/m2

< 25 kg/m2

Expected initial weight loss and likelihood of long-term maintenance Mean loss (kg)1 • ‘Do-it-yourself’ • Conventional dietitian plus behavioural input plus drugs • Surgery

0–10 4–5 5–10 6–12 20–30

Likelihood of 1–2-year maintenance (%) 10 40 60 80 60–80

Weight loss programme

Counsel

Audit

1

Mean loss usually includes non-responders

3

2

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dealt with independently as a priority. Weight loss and maintenance are of major value in reducing these risks, with or without additional risk factors, but obesity acts synergistically to increase the risk of coronary heart disease. • Greater physical activity and better diet (e.g. five fruit/vegetable portions per day) improve health even without weight loss. • Alcohol contains 7 calories/g (fat contains 9 calories/g, and carbohydrate 3.75 calories/g), does not stimulate or increase substrate oxidation, and tends to increase appetite. Heavy drinkers can be identified by elevated γ-glutamyltransferase (though this is also elevated in overweight individuals with fatty liver, a feature of central fat accumulation particularly associated with impaired glucose tolerance). It is usually not worth embarking on other measures of active weight management while patients continue to drink excessively. • Thyroid-stimulating hormone should be measured to exclude hypothyroidism, which may be difficult to diagnose clinically. Hypothyroidism does not usually cause massive weight gain, but impedes weight loss and should be corrected at an early stage. • Prescribed and self-prescribed drugs should be evaluated. Various drugs can increase appetite and promote obesity, and obese patients often spend large amounts of money on proprietary treatments. The approach to weight management depends on the starting BMI (or waist circumference) and the wishes of the patient. Patients with BMI more than 30 kg/m2 (or waist > 102 cm in men, > 88 cm in women) are likely to have multiple symptoms, particularly when aged over 40 years, and to develop risks of secondary diseases. They should be helped to lose as much weight as possible in a 3-month period. Diet and lifestyle methods can be used; the most rapid results are achieved with very low-calorie diets under supervision. Achievable weight loss in this time should be about 10–15 kg, which is a reasonable aim. Many patients lose less, but a loss of 5–10 kg has medical benefits (Figure 5) and should be considered a success. Even those who lose less than 5 kg cannot be deemed failures, provided their weight has not continued to increase along its expected trajectory. After 3 months, it is important to offer the patient a structured management programme for weight maintenance, which is the long-term aim. Patients with BMI 25–30 kg/m2 (or waist 94–102 cm in men, 80–88 cm in women) may be offered a 3-month weight loss programme or a 3-month weight maintenance programme as the first stage. The long-term aim is prevention of weight gain, and it is important for patients to learn how to achieve this. The need for weight loss is less strong in this group and depends on the presence of associated risk factors and the wishes of the patient.

a review of the literature suggests that prolonged and regular professional contact is most important and physical activity has a role, but other approaches are variable. Different approaches may suit different individuals. Several options are available, perhaps presented to the patient as a menu, and the skills of the therapist are of paramount importance. A comprehensive national guideline for the integration of prevention and active weight management was produced in 1996 by the Scottish Intercollegiate Guidelines Network (SIGN, Figure 3), based on published evidence. The grading system for scientific evidence (similar to that used for systematic reviews and the Cochrane Library) relies heavily on placebo-controlled trials, but this approach is not possible when the trial treatment is lifestyle modification and when individuals often instigate their own, personal approach to ‘treatment’ (patients tend to vary their prescribed treatment when the aim is one as familiar as weight loss). For these reasons, even the best research may fail to appear in systematic reviews.

Health promotion The prevalence of obesity (identified by the epidemiological cut-off of BMI > 30 kg/m2) is now more than 15% – the WHO criterion of an epidemic. It is beyond the scope of health-care services to control this problem solely on a one-to-one clinical basis. The burden of disease would be greatly reduced by small reductions in rates of weight gain achieved by health promotion and other preventive measures. Health promotion can alert the population to the need to take action in the form of personal lifestyle changes or self-referral. A public awareness campaign based on waist circumference (a better and more understandable predictor of total body fat than BMI, Figure 4) could be used to encourage self-referral of those with weight problems before they develop secondary diseases. Practice audit and opportunist screening are other approaches.

Clinical management The first stage in weight management should be an assessment of overall health and compounding risk factors. • Symptoms related to overweight (tiredness, sweating, shortness of breath, poor sleep, back pain, arthritis, angina, stress incontinence, menstrual disturbances) should be documented. Some coincidental conditions (e.g. hypothyroidism, breast cancer) can be masked by obesity. • Cardiovascular risk factors (smoking, hypertension, hyperlipidaemia, diabetes, impaired glucose tolerance) should be

Use of BMI and waist circumference in weight management and health promotion Healthy normal range

• BMI (kg/m2) • Waist (cm) Men Women

18.5–25

Health risks increasing Make personal changes to control weight 25–30

High risk Seek professional help and management > 30

< 94 < 80

94–102 80–88

> 102 > 88

4

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Potential benefits of modest (10 kg) weight loss

Physical activity is an efficient process and expends remarkably little energy; used alone, it results in little weight loss. To achieve weight loss, patients should limit energy intake, while maintaining physical activity to preserve muscle mass. Diet composition – standard fixed diets are less effective than individually prescribed eating programmes based on energy requirements. An energy-deficit diet of about 600 calories/day below the predicted metabolic rate (Figure 6) achieves weight loss of 0.5–1 kg/week. Patients are more likely to adhere to this more generous diet than a fixed 1200 kcal/day or 1500 kcal/day. Appetite is most likely to be satisfied by a diet relatively high in carbohydrate and low in fat. This composition is also the most likely to lead to long-term weight maintenance and is therefore preferred. Weight loss can be achieved with a wide range of diet compositions. The ketogenic, low-carbohydrate diets used in the past are no longer recommended; they achieve weight loss (no better than that with high-carbohydrate diets), but once weight has stabilized they tend to increase cholesterol and impair glucose tolerance. Weight regain is often rapid. Very lowcalorie diets (< 1000 kcal/day) should not be used without an effective means of preventing weight regain. The dietary profile for healthy weight loss should be compatible with that for health in the general population. Conventional recommendations (e.g. five portions of fruit or vegetables per day) apply. Slimming diets based on low-fat approaches lead to improved blood lipids compared with low-carbohydrate diets giving the same degree of weight loss. Eating behaviour – some ‘mystique’ has come to surround ‘behavoural therapy’, but many well-publicized formal models (e.g. cognitive behavioural therapy, motivational counselling) have not been shown to have any advantage over common-sense

Mortality • Decrease of > 20% total mortality • Decrease of > 30% diabetes-related deaths • Decrease of > 40% obesity-related cancer deaths Newly diagnosed type 2 diabetes mellitus • Decrease of 50% fasting glucose Blood pressure • Decrease of 10 mm Hg systolic • Decrease of 20 mm Hg diastolic Lipids • Decrease of 10% total cholesterol • Decrease of 15% low-density lipoprotein • Decrease of 30% triglycerides • Increase of 8% high-density lipoprotein Source: Scottish Intercollegiate Guidelines Network

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Patients with BMI less than 25 kg/m2 (or waist < 94 cm in men, < 80 cm in women) need a programme of healthy eating advice. Some may require counselling for eating disorders.

Weight management programmes Components of a 3-month weight loss programme: ultimately, weight loss can be achieved only when calorie intake is less than calorie output. Increasing calorie output is difficult in the obese, because physical activity is already elevated by the carrying of extra weight, and the risk of damage to joints and the back is greater.

Estimation of basal metabolic rate (BMR) and daily energy expenditure from body weight (W) and activity level, and its use in prescribing energy-deficit diets Age (years) Men • 10–18 • 18–30 • 30–60 • > 60

BMR (kcal/day)

Activity level

24-hour energy expenditure (kcal/day)

17.5 x W + 651 15.3 x W + 679 11.6 x W + 879 13.5 x W + 487

Men • Inactive • Light • Moderate • Heavy

BMR x 1.30 BMR x 1.55 BMR x 1.78 BMR x 2.10

Women • 10–18 • 18–30 • 30–60 • > 60

12.2 x W + 746 14.7 x W + 496 8.7 x W + 829 10.5 x W + 596

Women • Inactive • Light • Moderate • Heavy

BMR x 1.30 BMR x 1.56 BMR x 1.64 BMR x 1.82

Example 75 kg housewife aged 50 years BMR = 8.7 x 75 + 829 = 1482 kcal/day Daily energy expenditure = 1482 x 1.56 = 2311 kcal/day To achieve weight loss, subtract 500–600 kcal/day – in this example, 1800 kcal/day should be prescribed Standard deviations of differences between actual BMRs and estimates are about 150 kcal/day in men and 120 kcal/day in women. The activity factor assumes that 20 minutes/day of ‘cardioprotective’ exercise at 60% maximal work output is also prescribed. 6

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approaches. Obese patients need advice on how to eat, where to eat, when to eat and possibly with whom to eat. The eating habits of the overweight are often disorganized and they appear not to eat regular, normal meals. Simple advice introducing discipline into eating habits is valuable; for example: • eat three meals per day • do not consume snacks outside these meals • eat only when sitting down • eat only off a plate • never eat with the fingers. It is sometimes helpful to negotiate behavioural changes with patients, seeking a commitment to adhere to a particular rule for a period of, for example, 4 weeks, and then evaluating continuation or adoption of new measures. Specific guidance is often required for eating out and entertaining. Physical activity – a first stage in weight management is often to identify and minimize periods of total inactivity (e.g. television watching). Activities involving human contact, particularly during evenings, promote movement and reduce the inclination to snack. The principal need during weight loss is to maintain muscle mass with relatively low levels of activity (e.g. walking rapidly for 30 minutes daily). The exact level must be negotiated with the patient and adhered to. As fitness increases, activity can be increased, and is important in long-term weight maintenance. In some regions, physical activity in, for example, aerobic classes can be prescribed. Patients can also be encouraged to make a financial commitment to improving their health. Self-esteem – many overweight patients have low confidence and self-esteem. Their weight interferes with personal, social and occupational activities. The unemployed tend to be overweight and weight increases when employment is lost. Self-esteem can be improved by giving praise for healthy changes in lifestyle. Employment outside the home improves confidence and steps towards this may include unpaid activities such as voluntary work, evening classes or social activities. Finding personal rewards and treats that are not food-based is essential. Delivering a structured programme for weight loss – management of obesity requires a multidisciplinary approach. Few specialized skills are available in hospital-based management and attendance is likely to be better in a primary care setting with trained teams. A ‘rolling programme’ of weekly or fortnightly sessions ensures that adequate reinforcement is provided at the end of 12 weeks. The need for a multicomponent programme delivered by a single therapist emphasizes the importance of specific training. In primary care, a practice nurse is often asked to take responsibility for weight management. It is essential that other members of the primary care team (importantly, the doctors) understand the principles, difficulties, aims and success criteria of weight management. Evidence indicates that results are better with group approaches than one-to-one. Specific training in running groups is required. However, it must be recognized that some patients find groups threatening, so a class approach, perhaps with the option of oneto-one consultations, may be preferred.

Drugs that cause weight gain Drug • Insulin, sulphonylureas, thiazolidinediones • β-adrenergic blockers • Corticosteroids • Cyproheptadine • Antipsychotics • Sodium valproate • Some steroid contraceptives • Tricyclic antidepressants • Lithium

Hypertension Various inflammatory diseases Allergy, hay fever Psychosis Epilepsy Contraception Depression Bipolar disorder

Alternative drugs or proactive weight management advice should be given to patients with weight problems

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health professionals, increased physical activity and a low-fat, higher-carbohydrate diet are known to improve long-term weight maintenance. Simply switching to a low-fat diet (compared with the usual high-fat Western diet) has been shown to reduce weight by 1–3 kg over 1 year. These results have often been considered disappointing, but in the context of an overweight population that tends otherwise to gain weight at 1–2 kg/year, this approach may prevent weight gain, with long-term benefits.

Drugs in obesity Several drugs provoke weight gain (Figure 7), for various reasons. When prescribing them, it is important to discuss this hazard, with advice to join a weight maintenance class. Alternative treatments are usually available. Many drugs cause weight loss through nausea or other sideeffects. A few have been used therapeutically, primarily to reduce food intake (amphetamines, fenfluramines, sibutramine) or increase energy loss (β3-stimulant thermogenic agents, tetrahydrolipstatin to inhibit fat digestion). Two well-studied drugs with different modes of action (tetrahydrolipstatin and sibutramine) have become available for weight management. They induce weight loss significantly greater than that achieved by diet alone (about 3–5 kg) by inducing an energy deficit of about 300–400 kcal/day, and by this mechanism can maintain a body weight reduction of 12–15 kg. No drug can produce major and sustained weight loss when used alone, so the management of overweight patients remains multifactorial. Some patients find it impossible to adhere to dietary and lifestyle modification, and in these individuals adjunctive drug therapy may be considered and continued if effective. The main aim is to prevent weight gain or regain. Drugs induce weight loss slowly and may be more appropriate in long-term maintenance following weight loss by other means (e.g. very low-calorie diet). Criteria for drug therapy vary. BMI more than 30 kg/m2 is a clear indication; at BMI 25–30 kg/m2, a high risk of medical complications may justify their use. Anti-obesity drugs are inappropriate in pregnancy and in children. The sideeffects of centrally acting agents may be greater in the elderly. Orlistat (tetrahydrolipstatin) is almost entirely unabsorbed into the body and exerts its effect by competitive inhibition

Weight maintenance: it is proposed that a 12-week cycle of classes or group sessions in weight management, with guidelines similar to those for weight loss, be established. At present, there is no evaluated model of good practice, but regular contact with

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of intestinal lipase. To be absorbed, dietary fat (triglycerides) must be hydrolysed by lipase. Orlistat is taken three times daily, before main meals, and leads to malabsorption of about 30% of consumed fat. Provided total fat consumption is less than about 90 g/day, this malabsorption produces no symptoms. If the patient remains on a high-fat diet, however, detectable steatorrhoea occurs. Gastrointestinal symptoms reported by patients taking orlistat are therefore effects, not side-effects, of the drug. Minor depletion of fat-soluble vitamins has been reported with prolonged use, but not to deficiency levels. The clinical benefits of orlistat result from malabsorption of about 30 g fat/day, reducing absorbable energy consumption by about 300 kcal/day. Orlistat should be used only in patients who can adhere to a low-fat diet (< 30% energy as fat). Above this, fat malabsorption becomes intolerable, resulting in either correction of the diet (and weight loss) or discontinuation of the drug (and no weight loss). In patients who achieve 5% weight loss at 12 weeks, orlistat can be continued long term and a mean weight loss and maintenance of 10–15% is expected from clinical trial evidence. All cardiovascular risk factors improve with the weight loss. Lipid levels decrease slightly more than expected because of fat malabsorption. The mean additional weight loss of 3 kg with orlistat is maintained for at least 4 years and reduces the incidence of new diabetes by more than 30%. Sibutramine is a serotonin and noradrenaline re-uptake inhibitor that is relatively ineffective as an antidepressant but has a pro-satiety effect. Patients feel full for longer after eating and on average consume about 300 kcal/day less than with placebo. The drug does not appear to cause loss of appetite (this is occasionally reported as a side-effect, but is related to nausea). It has a small thermogenic effect (equivalent to about 100 kcal/day) by limiting the decline in metabolic rate that normally occurs with weight loss. The most common side-effects (dry mouth, constipation) are features of reduced food intake and can be minimized by drinking more water and eating more dietary fibre in the form of fruit and vegetables. Sibutramine should be avoided in patients with arrhythmia or uncontrolled hypertension. The weight loss achieved with sibutramine is about 3–5 kg better than that with placebo over 3 months. In the long term, stabilization at 12–15 kg less than that before treatment is predicted. Sibutramine treatment leads to an overall improvement in cardiovascular risk factors, though its hypotensive effect is attenuated by its sympathomimetic effects. Duration of drug treatment for obesity – withdrawal of orlistat or sibutramine usually leads to regaining of weight towards that which would have been reached without treatment (i.e. 1–2 kg/year above the starting point). With orlistat, a long period of treatment might help patients learn to accept and choose a much lower fat intake, but evidence for this is scarce. Withdrawal of an effective anti-obesity drug leads to rapid increases in cardiovascular risk factors and a need for other drugs. There is clinical trial evidence for safety and efficacy for up to 4 years (unusual for any drug), but current licences suggest that effective treatment should be withdrawn after 2 years (unusual for any drug controlling a disease). It is to be hoped that this regulatory inconsistency will be resolved. Whether treatment is stopped and restarted as a new 2-year course, or simply continued off-licence, patients need continued medical supervision and monitoring of risk factors.

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Some patients fail to respond, and can usually be detected by failure to lose 2 kg after 4 weeks. The drug should be stopped, because long-term success is unlikely. There is no evidence that increasing the dose improves results.

Surgery Vertical banded gastroplication is a widely used surgical approach that limits food consumption by the creation of a 15–20 ml upper gastric pouch with a 10 mm diameter outlet. It may be considered in the very obese (BMI > 35 kg/m2), in whom medical risks are high, but only with the help of a multidisciplinary team for support and long-term medical and dietetic supervision. It has recently become clear that weight regain is common after 2 years. Gastric bypass with Roux-en-Y is more effective, with sustained weight loss of 50–60 kg. A liquid-based, low-calorie diet for 3 months before surgery reduces intra-abdominal fat and liver rigidity (from intrahepatic fat), making the operation easier. This is particularly important when laparoscopic methods are used, to minimize trauma and risks. After surgery, a liquid diet for 3 months may improve the outcome by allowing healing. Surgery should not be attempted in patients who are unable to follow this diet for a test period of 2–3 months. Mortality is about 1%, but gastroplication can be justified by reduced medical risks in the long term and by greatly improved quality of life. Full results are awaited from a large Swedish study comparing surgical and medical management. u FURTHER READING Lean M E J, Han T S, Seidell J C. Impairment of Health and Quality of Life in People with Large Waist Circumference. Lancet 1998; 351: 853–6. Manson J E, Colditz G A, Stampfer M J et al. A Prospective Study of Obesity and Risk of Coronary Heart Disease in Women. N Engl J Med 1998; 322: 882–9. Scottish Intercollegiate Guidelines Network. Obesity in Scotland: Integrating Prevention with Weight Management. Edinburgh: Scottish Intercollegiate Guidelines Network, 1996. WHO. Obesity: Preventing and Managing the Global Epidemic. Geneva: WHO, 1998.

Practice points • Obesity is a multifactorial disease demanding multidisciplinary management • Specialist training in nutrition and weight management is desirable for all members of the primary care team • Management can follow published guidelines, but benefits from audit • The first aim is to prevent weight gain/regain • Weight loss should be limited to 3–4 months (or 5–15 kg at 0.5–1 kg/week), which leads to major medical benefits • Exercise improves morale and helps weight maintenance • Any patient can lose weight if calorie intake is restricted

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