3. Obesity in Adults

Obesity in Adults

This PatientPlus article is written for healthcare professionals so the language may be more technical than the condition leaflets. You may find the abbreviations list helpful.

Obesity is a growing problem in most developed countries and is responsible for a significant degree of morbidity and mortality in the Western world. There are several facets to the problem of obesity:

  • The prevention of obesity
  • The correction of obesity
  • The population-based approach
  • The individual approach

Prevention is better than cure and easier. The population-based approach is very important but the doctor in his surgery will have to cope with the individual and so this will be the thrust of this article.

You may wish to read the separate related article Obesity in Children for more information about this problem in children and young people.

The National Institute for Health and Clinical Excellence (NICE) recommends the use of both the Body Mass Index (BMI) and waist circumference to assess overweight and obese individuals, as different health risks have been defined for different combinations of these two measures.[1]

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The BMI

In adults, the diagnosis of obesity is most commonly made using BMI levels. BMI is calculated as weight in kilograms (kg) divided by height in metres squared (m2). As a general rule, an ideal BMI is 20 to 25. The following terms are used:[2] 

  • A BMI of 25-29.9 kg/m2 is overweight.
  • A BMI of 30-34.9 kg/m2 is obese (Grade I).
  • A BMI of 35-39.9 kg/m2 is obese (Grade II).
  • A BMI of ≥40 kg/m2 is obese (Grade III) or morbidly obese, meaning that weight is a real and imminent threat to health.

There are a few exceptions that are worthy of note:

  • A person who is very muscular will have a great weight in muscles and bone to support the muscles and so may have a high BMI without an excess of fat.
  • In the elderly, the lowest morbidity is in the group with a BMI of 25-30 rather than 20-25.[3]

Waist-hip ratio

An alternative measure of obesity is the waist-to-hip ratio (WHR).[4] It indicates abdominal fat and is a more accurate predictor for cardiovascular risk than BMI in different ethnic populations, as well as being more valuable in those over 75 years old.[5][6] The upper limit for acceptable is 0.90 in men and 0.85 in women.

According to 2010 figures, about 26.1% of adults in England (aged 16 or over) were obese and 62.8% were overweight or obese.[7] The figures showed that prevalence of obesity doubled over the preceding 25 years. This increasing trend was seen globally but was more marked in England than in many other countries.The UK currently has the highest prevalence in Europe.[8] Using BMI and waist circumference to assess risk of health problems, 22% of men and 14% of women were considered to be at high risk.[9]

An evaluation of the economic costs of chronic disease for the years 2006-2007 showed that overweight and obesity cost the NHS £5.1 billion compared to £3.3 billion for smoking.[10] For the year 2002, the total financial impact of obesity on employment was calculated at approximately 10 billion pounds.[11]

Several factors have now been shown to predict the development of obesity in individuals, such as a family history of obesity, lifestyle, diet and socio-economic factors.[1]

Genetic factors

The medical profession is traditionally sceptical about claims that obesity 'runs in the family'. However, the mapping of the human genome, combined with evidence from single-gene mutation cases and animal cross-breeding experiments, have identified a significant link between genetic factors and obesity. It is emerging that obesity is the result of a complex pathophysiological pathway involving many factors that control adipose tissue metabolism.[12] Cytokines, free fatty acids and insulin all play a part and genetic defects are likely to have a significant effect on the fine balance of this process.[13]

  • A patient may present directly asking for help.
  • Confrontation of the problem may arise opportunistically when the patient presents for something else.
  • It may be a related problem for the patient with diabetes, coronary heart disease, osteoarthritis or snoring.

The following groups are particularly in need of help and advice:

Obesity treatment or advice should be offered to:

  • Patients with a BMI >30.
  • Patients with a BMI >28 and comorbidities such as chronic obstructive pulmonary disease (COPD), ischaemic heart disease and diabetes.
  • Patients who are overweight and have diabetes, other severe risk factors or serious disease.
  • Patients who appropriately self-refer.
  • Parents of families with more than one obese member. This group may need special consideration and more intensive support.
  • Prevention advice should be offered to high-risk individuals - eg, those with a family history of obesity, smokers, people with learning disabilities, low-income groups.
Table adapted from National Obesity Forum Guidelines.[14]

History

  • Physical or psychological problems associated with obesity.
  • Ask: "Why do you want to lose weight?" The response may give an indication of motivation.
  • Past medical history, including history of dieting.
  • Social history, including diet, exercise, occupation, smoking.
  • Family history, including history of obesity, diabetes, heart disease.

Drugs that aggravate weight gain

  • Oral hypoglycaemic agents, especially sulfonylureas and thiazolidinediones ('glitazones') - so use metformin first-line.
  • Antidepressants including tricyclics, mirtazapine, monoamine-oxidase inhibitors.
  • Anticonvulsants, particularly sodium valproate, gabapentin, vigabatrin.
  • Antipsychotics, especially the atypical antipsychotics amisulpride, aripiprazole, clozapine, olanzapine, quetiapine and risperidone. 
  • Corticosteroids.
  • Oral contraceptives, hormone replacement therapy.
  • Beta-blockers.
  • Pizotifen.

Conditions that may affect weight[2]

  • Hypothyroidism.
  • Cushing's syndrome.
  • Growth hormone deficiency.
  • Polycystic ovarian syndrome.
  • Hypothalamic damage.
  • Genetic syndromes associated with hypogonadism.

Examination

  • Weight, height and BMI.
  • Blood pressure measurement - using an appropriately sized cuff.
  • Waist circumference should be no more than 88 cm in women and 102 cm in men.
  • Bioelectrical impedance analysis gives a more accurate assessment of body fat and lean tissue mass. This is usually unnecessary and the other measures can all be made with simple equipment found in any surgery.

Investigations

Consider:[1]

  • Urinalysis - for glucose and protein.
  • Microalbuminuria screen - the value of this test is not limited to those with diabetes.[15]
  • U&Es and LFTs.
  • Fasting blood glucose, unless already known to have diabetes.
  • Fasting lipid profile.

In addition, a few other investigations may be required, as indicated by history and examination.

  • Hormone profile including sex hormones and cortisol. Hormonal causes of obesity are rare and cortisol may be slightly elevated simply by obesity.
  • TSH - hypothyroidism is a rare cause of obesity and does not cause gross obesity.
  • Other investigations, as suggested by comorbidities - eg, ECG, CXR.

Risks of obesity

A meta-analysis found that all grades of obesity were associated with significantly higher all-cause mortality.[16]

The National Audit Office (NAO) report included a calculation of relative risks of other diseases resulting from obesity. The risks are just averages and risks increase with increasing obesity.

Relative increased risk of diseases in obesity
Disease Relative risk for women Relative risk for men
Type 2 diabetes 12.7 5.2
Hypertension 4.2 2.6
Myocardial infarction 3.2 1.5
Cancer of the colon 2.7 3.0
Angina pectoris 1.8 1.8
Gallbladder disease 1.8 1.8
Ovarian cancer 1.7 N/A
Osteoarthritis 1.4 1.9
Stroke 1.3 1.3

Obesity is an important risk factor in the development of chronic respiratory disorders such as COPD, asthma, obstructive sleep apnoea and obesity hypoventilation syndrome.[17]

If the person develops a surgical condition, diagnosis is more difficult and almost every postoperative complication is more frequent, including deep vein thrombosis, chest infection and wound dehiscence. Not only is osteoarthritis more common but treatments such as total hip replacement are more likely to be problematical in obesity.

Obesity increases the risk of breast cancer[18] and carcinoma of the endometrium.[19] Polycystic ovarian disease is usually a disease of the obese. Obesity impairs fertility, especially in the female. One study suggests that type 2 diabetes may be associated with an increase in visceral fat mass (ie abdominal fat) as opposed to general adiposity.[20]

Benefits of weight loss

If an obese person loses 10% of body weight, it is said to confer the following benefits:

  • In those with hypertension there is a fall of 10 mm Hg in both systolic and diastolic pressure.
  • In those newly diagnosed with diabetes, an abnormal fasting blood glucose falls in 50%.
  • In impaired glucose tolerance:
    • There is >30% fall in fasting or two hours insulin levels.
    • >30% rise in insulin sensitivity.
    • 40-60% reduction in the rate of progress to overt diabetes.
  • Lipid profiles improve with:
    • 10% fall in total cholesterol.
    • 15% fall in LDC.
    • 8% rise in HDC.
  • Mortality improves with:
    • >20% fall in all-cause mortality.
    • >30% fall in mortality related to diabetes.
    • >40% reduction in mortality related to obesity.
By the end of the assessment, you should have an idea of:[21]
  • The degree of the problem.
  • Any underlying physical contributing factors (medical problems, medication).
  • Comorbidities.
  • Risk of developing complications.
  • Lifestyle in terms of exercise and diet.
  • Person's feelings about being overweight
  • Person's willingness and motivation to try to lose weight

There is no quick fix. The World Health Organization sees obesity as a chronic disease. Management is not simply helping to shed some unwanted weight but a long-term approach to change attitude, habits and values for the rest of that person's life.

General points

  • The majority of obese patients can be managed successfully by the primary healthcare team with only a very few requiring referral for specialist help.[22]
  • Many practices offer weight management clinics but this is not the only source of help. Some people may prefer to attend WeightWatchers® or similar groups. One study found that commercial weight loss clinics were more effective than services provided by specially trained staff in primary care.[23]
  • The following should be included in a plan of action:[1]
    • Identify the causes that have made the person obese. There are probably several contributory factors.
    • Reiterate why the patient wants to lose weight to emphasise potential benefits and incentives and perhaps to ascertain the degree of motivation.
    • Examine what can be done to facilitate weight loss (eg, an exercise programme).
    • Set realistic targets for rate of loss of weight and desired end point. For a person who has a BMI above 35, the aim of a BMI of less than 25 is probably unrealistic.

Overview of management of different categories of obesity[2]

  • Overweight
    • Low waist circumference (<80 cm in women, <90 cm in men) - general advice on weight and lifestyle.
    • High waist circumference - structured advice regarding diet and exercise.
    • Comorbidities - structured advice on diet and activity; consider drug treatment after evaluating the effect of lifestyle changes.
  • Obese (I)
    • No comorbidities - structured advice regarding diet and exercise.
    • Comorbidities - structured advice on diet and activity; consider drug treatment after evaluating the effect of lifestyle changes.
  • Obese (II)
    • No comorbidities - structured advice on diet and activity; consider drug treatment after evaluating the effect of lifestyle changes.
    • Comorbidities - structured advice on diet and activity; consider drug treatment after evaluating the effect of lifestyle changes. Consider referring for surgery (follow local protocol).
  • Obese (III)
    • Structured advice on diet and activity. If available, this may need to be via a specialised weight management programme.
    • Consider starting drug treatment after evaluation of lifestyle changes.
    • Consider referring for surgery (follow local protocol).

Diet and exercise

Aim for both dietary modification and the initiation of exercise. Losing weight without exercise is very difficult. This is one reason for early intervention, before exercise is severely limited by morbid obesity, coronary heart disease, severe COPD, severe osteoarthritis or other such diseases that prevent physical exertion. The initial aim should be towards a daily 500 Kcal deficit of energy requirements through change in dietary habits and exercise.[24]

Diet

  • Diet and cognition - the first problem may be to convince the patient that he or she is eating too much. It is important to explain to the patient that the equation about calories in and calories out has no exception. It may be helpful to ask the patient to keep a food diary, including all snacks and drinks taken.
  • Dietary advice - there are many different approaches to dieting; be flexible to find the one that suits the individual. Useful tips are provided by the Norfolk and Norwich University Hospital.[25] Recent studies suggest that the intake of dietary sugars is a determinant of body weight. Modifying intakes seems to be mediated via changes in energy intakes,[26]

There may be occasions where there is benefit in referral to a dietician. However, if more than a tiny fraction of obese people within the catchment area is referred, it would swamp the service. The practice may have diet sheets to hand out.

Exercise

  • Value of exercise - this is more than just the calories expended in the session. It tends to increase basal metabolic rate and, after vigorous exercise, metabolism is stimulated for the next 36 hours. It also helps people to feel good about themselves.
  • Realistic expectations - people who are obese may have done no exercise for many years. It is important to discuss the options to find something appropriate and sustainable. It must also be something that the individual will enjoy; otherwise, he or she will not persevere. An overambitious programme is doomed to failure. An inadequate programme will confer no benefit. See separate article  Physical Training.
  • Expert advice - guidelines suggest that patients should be encouraged to exercise for a total of 150 minutes a week. One way to approach this is to do 30 minutes of moderate-intensity activity in bouts of 10 minutes on at least five days a week. Another method is to do 75 minutes of vigorous-intensity activity spread throughout the week or a combination of moderate and vigorous activity.[27]

Drug management

General points

  • Drugs have a limited role in the management of obesity. Their use is governed by strict criteria which should be met before medication is prescribed. These criteria are laid down by NICE and the licensing requirements of the drug manufacturers.[1]
  • Anti-obesity drugs should only be considered after diet, behavioural changes and exercise have been tried and evaluated. If the patient's weight has reached a plateau despite these measures, drug treatment may be considered.
  • Drug treatment may be used to maintain weight loss, rather than continue to lose weight.
  • Currently, the only drug available for the management of obesity is orlistat.
  • Vitamin and mineral supplements should be considered, particularly for vulnerable groups like the elderly and growing adolescents.
  • Those with type 2 diabetes may lose weight at a slower rate and appropriate allowance should be made.
  • Regular review of adverse effects and to reinforce lifestyle advice is important.
  • People being withdrawn from drugs should be offered support because it is at this time that their self-confidence and belief in their ability to make changes may be low.

Orlistat[28]

  • Action - orlistat is a lipase inhibitor which acts by reducing the absorption of dietary fat. About 30% of the fat that would otherwise be absorbed passes straight through to the large bowel.[1]
  • Effectiveness[1] - orlistat significantly increases weight loss compared to placebo but its effectiveness is limited by its side-effects.[8] Clinical trials suggest a moderate weight loss compared to placebo - about 2-5 kg over a year. There is also a small but significant reduction in total cholesterol, the ratio of total cholesterol to high-density lipids and systolic and diastolic blood pressure. Most patients gain weight after stopping treatment but trials suggest it takes three years to gain weight lost in one year on the drug.
  • Indications[1] - individuals aged between 18 and 75 with a BMI of 28 kg/m2 or more in the presence of significant comorbidities (eg, type 2 diabetes, high blood pressure, hyperlipidaemia) OR a BMI of 30 kg/m2 or more with no associated comorbidities. These individuals should be on a mildly hypocaloric, low-fat diet.
  • Prescription:
    • Availability[29] - this is now available over-the-counter (OTC) to individuals with the above criteria. The recommended OTC dose is 60 mg three times a day and treatment under pharmacist care should not exceed six months. Pharmacists should check the patient's BMI on each occasion a request is made. There has been some resistance among medical professionals with regards to the benefits at this lower dose, the potential lack of ongoing professional support and monitoring and the possibility of demotivation in the absence of rapid results. There have also been concerns that this initiative will detract from the message about eating less and exercising more.Time will tell whether these fears are justified.
    • Cautions - absorption of fat-soluble vitamins may be impaired. If on long-term therapy, monitor A, D, E and beta-carotene levels and prescribe supplementation if appropriate. Additional contraception may be needed in women experiencing marked gastrointestinal side-effects (eg, diarrhoea). Underlying kidney disease may result in hyperoxaluria and oxalate nephropathy.
    • Contra-indications - chronic malabsorption syndrome, cholestasis, pregnancy and breast-feeding.
    • Interactions[30] - ciclosporin (reduced bioavailability), acarbose (lack of pharmacokinetic data), amiodarone (reduced plasma concentrations), coumarins (enhanced anticoagulant effect), anti-epileptic drugs (decreased absorption). The lipophilic drugs fluoxetine and simvastatin do not seem to be affected by orlistat.[31]
    • Common problems - abdominal discomfort/distension, liquid oily stools, faecal urgency and increased frequency, flatulence - more so if a diet contains 2,000 Kcal/day and is high in fat. Other common problems include headaches, upper respiratory tract infections and hypoglycaemia. Less frequently, rectal pain, menstrual irregularities, anxiety, and fatigue occur.[28] Concerns were raised in post-marketing surveillance of liver damage. However, a meta-analysis reported that this is likely to occur rarely.[32]
  • Initiation - prescribe one tablet (120 mg) before, during or after each main meal (a dose may be missed if the meal contains no fat). No more than three tablets in a day.
  • Monitoring[2] - check weight at three months and at six months. If unbalanced diet, also monitor fat-soluble vitamin levels. Specifically enquire about side-effects (especially gastrointestinal) and look for drug interactions.
  • Ending treatment - treatment should only be continued beyond three months if a further 5% of body weight has been lost since start of treatment (this target may be made more lenient for those with type 2 diabetes). The use of drug treatment for longer than 12 months (usually for weight maintenance) should be made after discussing potential benefits and limitations with the patient.

Sibutramine (withdrawn)

  • Action - this is a centrally-acting serotonin and noradrenaline reuptake inhibitor which has the effect of promoting satiety and increasing energy expenditure.[33] Its use has been suspended in the UK amid fears that it increases the risk of heart attacks and strokes.[34] Some researchers maintain that sibutramine could still be a useful option in patients who do not have pre-existing cardiovascular disease.[35]

Rimonabant[36]

  • Rimonabant was a selective cannabinoid 1 (CB1) receptor antagonist which has now had its marketing suspended. The European Medicines Agency completed a review of rimonabant (Acomplia®, a treatment for obesity) after concerns about its psychiatric safety - the benefits of rimonabant do not outweigh the risks of psychiatric reactions in clinical use. An ongoing trial is examining a role for rimonabant in the treatment of binge eating disorder.[37]

Surgery

See separate article Bariatric Surgery.

Alternative or complementary therapies

A number of such therapies has been put forward as remedies to the problem and may be very attractive to prospective customers. However, the evidence base for these treatments is really not there. The exception has been with acupuncture. A review of the literature supported the use of acupuncture but concluded that more research was needed.[38]

Psychological aspects

Consider cognitive and behavioural therapies to assist in behaviour modification, ie help the patient to identify the wrong attitudes and actions in their lives, to understand why they are wrong and need to be rectified, to identify correct responses and to implement them. It has been suggested that the most successful approach is likely to come from  therapy targeted towards specific eating disorders presenting in individual obese patients.[39] One study, however, questioned the effectiveness of psychological treatments in the long term.[40]

As with any chronic disease, follow-up must be arranged. This implies interest in the patient's progress. A fortnight to a month would be appropriate at first, with intervals getting longer with time; however, treat it as a chronic disease.

The practice may have a nurse-run weight control clinic. The achievement of a target weight is not the end of the process. Obesity is a chronic disease and needs to be managed throughout the person's life, as relapse is common. 'Yo-yo dieting' with weight going up and down is undesirable and unhealthy.

Consider secondary care referral if:

  • There are underlying causes which need investigating.
  • There are complex comorbidities.
  • If conventional treatment has failed in primary care.
  • If specialist interventions may be needed (eg, a very low-calorie diet).

For those who are obese, any loss of weight is beneficial and, within reason, the more the better; most of the complications of obesity can be reduced by weight loss.[2] However, the outlook is generally poor. Many people who have consulted a doctor about weight achieve little in terms of weight loss, or the loss is only temporary. Nevertheless, the stakes are such that every encouragement should be given to those who wish to try.

A 2007 Department of Health report predicted that It is feared that by 2050, up to 90% of adults will be overweight or obese. More recent modelling suggests that, without action, 41-48% of men and 35-43% of women could be obese by 2030. In the UK, obesity costs the NHS an estimated £4.2 billion but this is set to double by 2050 if current trends continue.

The problem of obesity needs to be addressed through a broad range of measures covering different aspects contributing to it. Thus, public health strategies are linked with matters such as town planning, convenience store planning, school food and exercise programmes and good information campaigns. The National Obesity Observatory has been set up in an effort to collate the research information and to provide a single point of contact for wide-ranging authoritative information on data and evidence relating to obesity, overweight, underweight and their causes, in order to support policy makers. See their website under 'Further reading & references', below.

On a positive note, gut hormone analogues and drug combinations are being researched and are showing promising results.[41]

Studies report that metformin it is an effective weight-reducing drug in non-diabetic overweight and obese patients.[42]

This article has focused on the management of obese individuals but the future lies in the management of an obese society and, more particularly, in curbing and perhaps reversing the growing trend. A report released by the Royal College of Physicians concluded that the NHS does not currently have the resources to deal with the obesity epidemic and that further investment is required.[43]

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Further reading & references

  1. Obesity, NICE Clinical Guideline (2006)
  2. Obesity; NICE CKS, October 2012
  3. Kvamme JM, Holmen J, Wilsgaard T, et al; Body mass index and mortality in elderly men and women: the Tromso and HUNT studies. J Epidemiol Community Health. 2012 Jul;66(7):611-7. doi: 10.1136/jech.2010.123232. Epub 2011 Feb 14.
  4. Cameron AJ, Magliano DJ, Soderberg S; A systematic review of the impact of including both waist and hip circumference in risk models for cardiovascular diseases, diabetes and mortality. Obes Rev. 2013 Jan;14(1):86-94. doi: 10.1111/j.1467-789X.2012.01051.x. Epub 2012 Oct 17.
  5. Ashwell M, Gunn P, Gibson S; Waist-to-height ratio is a better screening tool than waist circumference and BMI for adult cardiometabolic risk factors: systematic review and meta-analysis. Obes Rev. 2012 Mar;13(3):275-86. doi: 10.1111/j.1467-789X.2011.00952.x. Epub 2011 Nov 23.
  6. Price GM, Uauy R, Breeze E, et al; Weight, shape, and mortality risk in older persons: elevated waist-hip ratio, not high body mass index, is associated with a greater risk of death. Am J Clin Nutr. 2006 Aug;84(2):449-60.
  7. Facts and figures on obesity, Dept of Health, April 2012
  8. Carter R, Mouralidarane A, Ray S, et al; Recent advancements in drug treatment of obesity. Clin Med. 2012 Oct;12(5):456-60.
  9. Trends in obesity prevalence; National Obesity Observatory, 2010
  10. Scarborough P, Bhatnagar P, Wickramasinghe KK, et al; The economic burden of ill health due to diet, physical inactivity, smoking, alcohol and obesity in the UK: an update to 2006-07 NHS costs. J Public Health (Oxf). 2011 Dec;33(4):527-35. doi: 10.1093/pubmed/fdr033. Epub 2011 May 11.
  11. The economic burden of obesity; National Obesity Observatory, 2010
  12. Xia Q, Grant SF; The genetics of human obesity. Ann N Y Acad Sci. 2013 Jan 29. doi: 10.1111/nyas.12020.
  13. Nam H, Ferguson BS, Stephens JM, et al; Impact of obesity on IL-12 family gene expression in insulin responsive tissues. Biochim Biophys Acta. 2013 Jan;1832(1):11-9. doi: 10.1016/j.bbadis.2012.08.011. Epub 2012 Aug 23.
  14. Guidelines on Management of Adult Obesity and Overweight in Primary Care; National Obesity Forum, 2006
  15. Lambers Heerspink HJ, Brinkman JW, Bakker SJ, et al; Update on microalbuminuria as a biomarker in renal and cardiovascular disease. Curr Opin Nephrol Hypertens. 2006 Nov;15(6):631-6.
  16. Flegal KM, Kit BK, Orpana H, et al; Association of all-cause mortality with overweight and obesity using standard body mass index categories: a systematic review and meta-analysis. JAMA. 2013 Jan 2;309(1):71-82. doi: 10.1001/jama.2012.113905.
  17. Zammit C, Liddicoat H, Moonsie I, et al; Obesity and respiratory diseases. Int J Gen Med. 2010 Oct 20;3:335-43. doi: 10.2147/IJGM.S11926.
  18. Petracci E, Decarli A, Schairer C, et al; Risk factor modification and projections of absolute breast cancer risk. J Natl Cancer Inst. 2011 Jul 6;103(13):1037-48. doi: 10.1093/jnci/djr172. Epub 2011 Jun 24.
  19. Carlson MJ, Thiel KW, Yang S, et al; Catch it before it kills: progesterone, obesity, and the prevention of endometrial cancer. Discov Med. 2012 Sep;14(76):215-22.
  20. Neeland IJ, Turer AT, Ayers CR, et al; Dysfunctional adiposity and the risk of prediabetes and type 2 diabetes in obese adults. JAMA. 2012 Sep 19;308(11):1150-9.
  21. Obesity; Dept of Health, February 2013
  22. Edmunds J et al; Motivating behaviour change and weight loss in overweight and obese patients in a primary care setting, HLI, 2009
  23. Jolly K, Lewis A, Beach J, et al; Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity: lighten Up randomised controlled trial. BMJ. 2011 Nov 3;343:d6500. doi: 10.1136/bmj.d6500.
  24. Management of obesity, Scottish Intercollegiate Guidelines Network - SIGN (February 2010)
  25. Dietary Tips to Help You with Your Weight Loss, Norfolk and Norwich University Hospitals NHS Foundation Trust
  26. Te Morenga L, Mallard S, Mann J; Dietary sugars and body weight: systematic review and meta-analyses of randomised controlled trials and cohort studies. BMJ. 2012 Jan 15;346:e7492. doi: 10.1136/bmj.e7492.
  27. Obesity and Physical Activity, Association for the Study of Obesity, 2012
  28. Summary of Product Characteristics (SPC) - Xenical® 120 mg hard capsules (orlistat), Roche Products Limited, electronic Medicines Compendium. Last updated April 2012
  29. Practice Guidance: OTC Orlistat; Royal Pharmaceutical Society of Great Britain, 2009.
  30. Filippatos TD, Derdemezis CS, Gazi IF, et al; Orlistat-associated adverse effects and drug interactions: a critical review. Drug Saf. 2008;31(1):53-65.
  31. Zhi J, Moore R, Kanitra L, et al; Effects of orlistat, a lipase inhibitor, on the pharmacokinetics of three highly lipophilic drugs (amiodarone, fluoxetine, and simvastatin) in healthy volunteers. J Clin Pharmacol. 2003 Apr;43(4):428-35.
  32. Morris M, Lane P, Lee K, et al; An integrated analysis of liver safety data from orlistat clinical trials. Obes Facts. 2012;5(4):485-94. doi: 10.1159/000341589. Epub 2012 Jul 23.
  33. Witkamp RF; Current and future drug targets in weight management. Pharm Res. 2011 Aug;28(8):1792-818. doi: 10.1007/s11095-010-0341-1. Epub 2010 Dec 23.
  34. Sibutramine: Suspension of marketing authorisation as risks outweigh benefits; Medicines and Healthcare products Regulatory Agency (MHRA), Jan 2010
  35. Paumgartten FJ; Unfeasibility of a risk mitigation strategy for sibutramine. Rev Bras Psiquiatr. 2012 Mar;34(1):118.
  36. Europe wide suspension of Marketing Authorisation for Acomplia® (rimonabant); Medicines and Healthcare products Regulatory Agency (MHRA), Oct 2008
  37. Pataky Z, Gasteyger C, Ziegler O, et al; Efficacy of rimonabant in obese patients with binge eating disorder. Exp Clin Endocrinol Diabetes. 2013 Jan;121(1):20-6. doi: 10.1055/s-0032-1329957. Epub 2012 Nov 12.
  38. Belivani M, Dimitroula C, Katsiki N, et al; Acupuncture in the treatment of obesity: a narrative review of the literature. Acupunct Med. 2012 Nov 15.
  39. Carter FA, Jansen A; Improving psychological treatment for obesity. Which eating behaviours should we target? Appetite. 2012 Jun;58(3):1063-9. doi: 10.1016/j.appet.2012.01.016. Epub 2012 Jan 25.
  40. Cooper Z, Doll HA, Hawker DM, et al; Testing a new cognitive behavioural treatment for obesity: A randomized controlled trial with three-year follow-up. Behav Res Ther. 2010 Aug;48(8):706-13. doi: 10.1016/j.brat.2010.03.008.
  41. Hainer V, Hainerova IA; Do we need anti-obesity drugs? Diabetes Metab Res Rev. 2012 Dec;28 Suppl 2:8-20. doi: 10.1002/dmrr.2349.
  42. Seifarth C, Schehler B, Schneider HJ; Effectiveness of metformin on weight loss in non-diabetic individuals with obesity. Exp Clin Endocrinol Diabetes. 2013 Jan;121(1):27-31. doi: 10.1055/s-0032-1327734. Epub 2012 Nov 12.
  43. Action on obesity; Royal College of Physicians, 2013
Original Author: Dr Olivia Scott Current Version: Peer Reviewer: Prof Cathy Jackson
Last Checked: 01/03/2013 Document ID: 3006  Version: 26 © EMIS

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.