Adult obesity and diet
Executive Editor, InnovAiT
Email: chantal.simon{at}oxfordjournals.org
 |
Abstract |
|---|
 TOP Abstract The GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
We are what we eat. Although rather clichéd, the level of fat in the diet of a population does directly mirror the incidence of heart disease and there are many other dietary factors which have both direct and indirect links with disease. For example, excess ingestion of salt is associated with high blood pressure; low roughage diets are associated with bowel cancer; ingestion of infected beef causes Creutzfeldt–Jakob disease; eggs may carry salmonella and some food additives have been associated with hyperactivity.
Overeating is also a health risk. More than one in five adults in the UK are currently classified as obese, having a body mass index (BMI) of 30 or more (Fig. 1). Currently, 67% of men and 58% of women in the UK are classified as overweight or obese. Moreover, recent evidence shows that obesity is increasing. Ten years ago, only 58% of men were overweight and 49% of women. Obesity does carry health risks, and obesity is set to take over from smoking as the number one preventable cause of disease in the UK. This article aims to outline a healthy diet, discuss the health risks of obesity and ways to reduce obesity in primary care.
GP curriculum statement 5 is about healthy people. General practitioners are at the forefront and must understand the principles of disease prevention and promotion of health. For this reason, it is vital that they have the appropriate skills to be able to promote health and apply prevention strategies for their patients in their communities. The consultation offers opportunities to discuss with patient's healthy living and the risks of unhealthy living and negotiate lifestyle modifications that patients can make to live more healthily. The identification of obese patients and those in need of dietary advice for other reasons is a key part of this process. In particular, a GP should be able to:
Curriculum statement 15.2 (Digestive problems) also specifically requires GPs to recommend five portions of fruit and vegetables daily as a preventative measure for digestive problems such as constipation and bowel cancer.
|
|
|
Barriers to a healthy diet |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
Before recommending a healthy diet to patients, it is perhaps important to reflect on why patients do not have a healthy diet. Cultural aspects and ignorance are major factors. We tend to like the foods that we have grown up with and think that they are good for us. It is hard to break the habits of a lifetime and change our diet, especially when there can be confusion about what is healthy to eat. Posters in the waiting room outlining a healthy diet, or leaflets that can be picked up by patients, may help. Ensure that the dietary advice given through this route is consistent, clear and simple. Beware of cultural differences. Food diagrams and information tend to be pitched at the classic Western diet. It is important to provide modified information for patients from other cultural backgrounds and those with special dietary needs.
The cost and presentation of food in the shops is also an important factor. Fresh fruit and vegetables are expensive, as are lean meat and fish. Emphasize to patients that some elements of a healthy diet, such as potatoes, pasta and rice, are cheap. Packaging may be confusing and misleading. For example, many breakfast cereals claim health benefits, but contain high levels of sugar. The use of convenience food—both frozen and ready meals and snacks—has increased dramatically over the past decade. This is due to lifestyle factors, such as an increase in the proportion of working women and forceful marketing of such foods. Many convenience foods contain a great deal of fat and have a lot of added salt and sugar.
Finally media and peer pressure is important. There is a general perception that a healthy diet is not enjoyable. It is important to stress to patients that a healthy diet is often tastier and more enjoyable than an unhealthy one. Children are under a lot of pressure both from their friends and from the constant bombardment that they face through television and other media, to eat sweets, crisps and other snacks and convenience foods such as burgers. Furthermore, the media causes confusion about what is the right thing to eat. There are recurrent food scares in the press and a food considered healthy one week may be branded unhealthy a week later. This, in turn breeds fatalism and apathy—a feeling that whatever you eat, it will be bad for you.
|
The role of the GP and primary health care team |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
Although most influence on diet comes from national food policy, price of food, advertising, general education and cultural influences, the primary health care team has a vital role to play in influencing the diet of the practice population.
First, the primary health care team has a role in screening the practice population to identify obese patients and patients in need of dietary advice for other reasons, for example those with coeliac disease or diabetes mellitus. Screening for obesity is recognized in the Quality and Outcomes Framework. Eight points are available if the practice can produce a register of patients aged 16 and over with a BMI recorded in the previous 15 months of 30 kg/m2 or more (Obesity 1). For diabetic patients, there are a further three points available for recording BMI (Diabetes 2). A sliding scale of points are available once a minimum of 40% of patients with diabetes have a BMI recorded, and the maximum three points are available for practices that have recorded BMI in 90% or more of their diabetic patients in the past 15 months. However, the Quality and Outcomes Framework does not currently reward practices for taking action to reduce obesity.
Once a patient in need of dietary advice has been identified, it is important to assess that patient carefully. Include in your assessment details of the patient's current diet, the patient's motivation to change and the barriers to change that will be faced. Explore the patient's knowledge about diet.
Once you have baseline information, decide on your plan of action. If the patient is unwilling to change, then provide information about healthy diet and the health risks of poor diet. Review the patient's diet at subsequent encounters.
If the patient is willing to change, provide information and negotiate some goals with the patient. Choose just two or three food specific goals on each occasion. Try to set targets that appear realistic and achievable, tailor them to the patient's existing diet and tie them into the patient's usual schedule. Set a review date with the patient and follow the patient up regularly.
|
The ideal diet |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
Figure 2 summarizes the rough proportions of the various food groups that should make up each meal. Encourage patients to eat regularly. There is debate about whether a regime of three larger meals or six smaller meals is more beneficial. Having smaller meals more frequently may be better for people who get hungry between meals. However, for people who find it hard to stop eating, eating more frequently may present more opportunities to overeat. In all cases, discourage uncontrolled snacking of junk food between meals. Advise patients to ask themselves the following questions when they feel like eating between meals:
- Am I hungry? If unsure, wait 20 minutes and then ask the same question again.
- When was the last time I ate? If less than 3 hours ago, it may not be real hunger.
- Could a small snack tide me over until the next meal? Have ready-to-eat fruits or vegetables on hand for this.
|
Composition and portion size of each meal should be adjusted to maintain a healthy weight.
- Include a variety of foods
- Use starchy foods such as bread, rice, pasta and potatoes as the main energy sources
- Eat plenty of fruit and vegetables. It is estimated that 8% of men and 6% of women consume no fruit or vegetables at all. Only 14% of men and 27% of women eat the recommended daily amounts of fruit and vegetables. Aim for more than five portions of fruit and vegetables (excluding potatoes) per day and ideally seven to nine portions per day. Encourage patients to keep the delay between cutting fruit and vegetables, to eating them, to a minimum. Do not overcook vegetables. Steaming is preferable to boiling. These measures preserve vitamin content.
- Eat plenty of fibre—good sources are as follows: high-fibre breakfast cereals, pulses, beans, whole-meal bread, potatoes (with skins), pasta, rice, oats, fruit and vegetables
- Eat oily fish, such as mackerel, herring, pilchards, or salmon, at least once or twice a week to promote cardiovascular health
- Consider substituting meat with vegetable protein, for example pulses or soya. Choose lean meat, remove excess fat and poultry skin and pour off fat after cooking to reduce intake to saturated fats. Avoid fatty meat products such as sausages, salami, and meat pies.
- Boil, steam or bake foods in preference to frying. When cooking with fat, advise patients to use unsaturated oil (for example, olive or sunflower oil) and to use cornflour rather than butter and flour to make sauces.
- Avoid high-fat dairy products, such as full-cream milk, butter or full-fat cheese. Use skimmed milks and low-fat yoghurts, spreads and cheese (such as Edam or cottage cheese).
- On average, adults eat about 9.5 g of salt a day. Ideally they should consume a maximum of 6 g a day. Three quarters of the salt in our diet comes from processed foods. Before buying processed foods, check the salt content on the label. High salt foods contain more than 1.5 g salt (0.6 g of sodium) per 100 g (and low salt foods contain 0.3 g salt (0.1 g of sodium) or less per 100 g. Avoid crisps and salted nuts. Ways to avoid adding salt to foods are listed in box 2.
- Avoid adding sugar to foods and cut back on foods containing high quantities of sugar (Box 2).
- Drink at least 4–6 pints (2–3 l) of fluid each day and preferably not tea, coffee or alcohol as these act as diuretics and can have other adverse effects on health. Drinking a large glass of water with meals and instead of snacks can reduce the urge to overeat.
- Avoid excessive alcohol intake—aim to consume less than 21 units per week for men and less than 14 units per week for women.
What is a portion of vegetables or fruit? One portion of vegetables or fruit is roughly equivalent to
What is a unit of alcohol? One unit of alcohol is 10 ml (1 cl) by volume, or 8 g by weight, of pure alcohol. One unit of alcohol is roughly equal to
There are 1.5 units of alcohol in
|
Adding flavour to cooking without using salt
Crown Copyright. Source: Foods Standards Agency Website: www.salt.gov.uk. Reducing sugar intake
|
|
Measurement and classification of obesity |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
The most common measure of obesity is BMI. BMI is calculated by dividing the weight of the patient in kilograms by the square of the height of the patient in metres (Fig. 3):
- Patients with BMI of 18.5–24.9 kg/m2 are classified as having normal weight
- Patients with BMI of 25–29.9 kg/m2 are classified as being overweight
- Patients with BMI of 30-39.9 kg/m2 are classified as being obese
- Patients with BMI of 40 kg/m2 or more are classified as morbidly obese.
|
|
|
|
Causes of and risk factors for obesity |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
There are many causes of obesity. About a third of those who are obese have a genetic predisposition. Inheritance is polygenic. These individuals are more prone to becoming obese again if they successfully diet.
Obesity results if the number of calories taken in exceeds the calories expended by the individual. Poor diet due to cultural factors and lack of education is the most common reason for excess calorie intake. Lack of physical activity, for example due to physical disability, is the most common cause of reduced calorie expenditure. Either can result in obesity. Prevention of obesity, therefore, begins in childhood by instilling healthy patterns of exercise and diet.
Women are prone to become obese after childbirth, especially if they do not breast feed, mainly due to failure to lose the weight gained in pregnancy. Rarely obesity has an underlying endocrine cause. Only investigate if there are other symptoms or signs of endocrine disease. Consider hypothyroidism, polycystic ovary syndrome and Cushing's syndrome. Rarely, obesity is the result of an ongoing binge eating disorder.
It is accepted that smoking cessation tends to cause weight gain with average weight gains of about 3 kg for men and 4 kg for women being commonly cited. Drug treatment may also cause obesity. Patients taking oral steroids (and rarely high dose inhaled steroids) may become Cushingoid. Patients on antipsychotics such as olanzapine may gain weight, and the sulphonylureas used to treat type 2 diabetes are associated with weight gain. Diabetic patients also often gain weight when they switch to insulin.
Patients often complain of weight gain when starting the combined oral contraceptive pill, the progesterone only pill or hormone replacement therapy. However, there is little evidence to support this. Weight gain with depo contraceptive injections is more widely accepted and it is estimated that women gain an average of 4.5 kg over 5 year's use, although up to 10% of women lose weight when using Depo contraception.
|
Health risks of obesity |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
Physical health risks
Obesity is a health risk for many physical health conditions (Table 2). Overall a BMI of 30 kg/m2 or more confers a three times increased death rate on an individual (Fig. 4).
|
|
Perhaps the most dramatic association is that between obesity and type 2 diabetes. It is predicted that there will be three million diabetics living in the UK by 2010. The prevalence of diabetes has increased by 65% in men and 25% in women since 1991. On some projections, by 2025 diabetes and its complications could account for a quarter of the health budget. The prevalence of diabetes is closely correlated to the prevalence of obesity with a 9- to 12-year time lag. Compared to women with a BMI of 22, women with a BMI of 28 have an 18-fold increased risk of diabetes, while those with a BMI of 35 have a staggering 92-fold risk of diabetes. Due to the increase in childhood obesity, type 2 diabetes is increasingly being seen in paediatric clinics.
It is thought that obesity triggers a state of insulin resistance resulting in both increased blood sugars and hyperinsulinaemia. Hyperinsulinaemia drives a host of metabolic disturbances. This is known as the metabolic syndrome and includes hypertension, hypercholesterolaemia, hypertriglyceridaemia, hypercoagulation, hyperviscosity and hyperuricaemia. Each in itself is a risk factor for cardiovascular disease, but together they are cumulative. Overweight and obesity are regarded as among the main modifiable risks associated with cardio- and cerebrovascular disease. The British Heart Foundation estimates that around 5% of coronary heart disease deaths in men and 6% in women are due to obesity and a higher proportion if the large number of overweight adults is also considered.
Obesity is also associated with cancer. About 20 different cancers have been associated with obesity, of which the most common are breast, endometrial, oesophageal and colonic cancers. Around 14% of cancer deaths in men and 20% in women are attributed to obesity making obesity the most important avoidable cause of death after smoking. Furthermore, death rates once a patient has cancer are higher in obese patients. In those morbidly obese, the chance of dying from a cancer once it has been diagnosed is 52% higher for men, and 60% higher for women, than that of a patient of normal weight.
Psychological health risks
The psychological consequences of obesity can range from lowered self-esteem to clinical depression. Rates of anxiety and depression are three to four times higher among obese individuals. Obese women are around 37% more likely to commit suicide than women of normal weight. Excess weight is also likely to lead to prejudice in school and the workplace, lower self-esteem and reduced job opportunities. For example, one study has demonstrated that teachers underestimate the IQ of overweight children.
|
Management of obese patients |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
When the body's intake is greater than output over a period of time, obesity results. Management of obesity aims to reverse this trend on a long-term basis. Encourage all patients to eat a healthy diet. Adjust the calorie intake within that diet to achieve weight loss. Follow up patients regularly to maintain motivation and monitor progress.
Low calorie diets
Obese people lose weight by reducing energy intake. A realistic goal is weight loss of 1–2 lbs (0.5–1 kg) per week, aiming for a target BMI of 25 kg/m2. Rates of weight loss in excess of 1 kg/week involve loss of lean tissue rather than fat. A weight loss of 1 kg/week is achievable using diets of 1000–1500 kcal/day for most adults. There is no health benefit of weight reduction below a BMI of 25 kg/m2. Weight loss in the first few weeks may be higher due to water and glycogen depletion and then slow down. Encourage patients to persist with their diets when this happens. If simple diet sheets are not effective, refer to a dietician.
Very low calorie diets
Diets of less than 800 kcal/day only have a limited place in management of obesity as this pattern of eating cannot be maintained and rebound weight gain is seen on stopping the diet. Only use to treat morbid obesity under strict supervision by a dietician.
Exercise
Regular aerobic exercise, preferably at least 20 minutes of moderate exercise per day, helps reduce weight and improve health. Tailor advice about exercise to the individual and local facilities.
Drug therapy
The drugs specifically licensed for the treatment of obesity in the UK are orlistat (120 mg tds with food), which acts by reducing fat absorption from the gastrointestinal tract and the centrally acting appetite suppressants sibutramine (10–15 mg od—monitor blood pressure and pulse rate closely) and rimonabant (20 mg mane). Consider prescribing drug therapy to aid weight loss if the patient has a BMI of 30 kg/m2 or more, or 28 kg/m2 or more in the presence of a comorbidity such as diabetes, hypercholesterolaemia or hypertension and has tried to lose weight unsuccessfully without drug support. There is little evidence to guide selection but it is logical to choose orlistat for those who have a high intake of fats and sibutramine or rimonabant for those who cannot control their eating. Combination therapy involving more than one antiobesity drug is contraindicated. NICE guidance on prescribing orlistat and sibutramine is summarized in Box 3. Guidance on prescription of rimonabant is expected later in 2008.
| Use of Orlistat Warn patients about common side effects: The major problems patients experience are gastrointestinal side effects—oily leakage from rectum, flatulence, faecal urgency, liquid or oily stools, faecal incontinence, abdominal distension and pain. Gastrointestinal side effects are minimized by reduced fat intake. NICE guidance: NICE has recommended (2001) that treatment with orlistat should be continued for more than 6 months only if at least 10% of the starting weight of the patient has been lost since the start of treatment. Use of sibutramine: Contraindications/cautions:
NICE guidance: NICE has recommended that sibutramine should be prescribed only for individuals who have attempted seriously to lose weight by diet, exercise and other behavioural modification. In addition, arrangements should exist for appropriate health care professionals to offer specific advice, support and counselling on diet, physical activity and behavioural strategies to those receiving sibutramine. Monitoring: Monitor BP and pulse rate
Discontinue if blood pressure is greater than 145/90 mmHg or if the systolic or diastolic pressure is raised by more than 10 mmHg above the baseline reading or if the pulse rate is raised by 10 beats/minute above the baseline reading at two consecutive visits Discontinue treatment if
In individuals with comorbid conditions, treatment should be continued only if weight loss is associated with other clinical benefits.
|
| Useful contacts and information for patients Food Standards Agency, Website: www.eatwell.gov.uk British Nutrition Foundation, Website: www.nutrition.org.uk Slimming world, Tel: 08700 754 666 (meetings enquiries) or 0870 330 7733 (customer services), Website: www.slimming-world.com Weightwatchers UK, Tel: 08457 123 0000 (meetings enquiries) or 0845 345 1500 (customer services), Website: www.weightwatchers.co.uk British Obesity Surgery Patients Association, Tel: 08456 02 04 46, Website: www.bospa.org.
|
Group therapy
Group activities, such as weightwatchers groups, seem to have a higher success rate in producing and maintaining weight loss.
Behavioural therapy
Behavioural therapy has been shown to be effective both for individuals and for groups, when combined with low calorie diets. In its simplest form it involves advice to avoid situations that tempt overeating.
Surgery
Only consider referral for surgery for obesity as a last resort, when behavioural and dietary modification have failed and BMI is greater than 40 kg/m2. Gastroplasty is the most common procedure. The five most common complications of surgery for obesity are dumping syndrome, which includes vomiting, reflux and diarrhorea (20%); anastomosis complications, such as leaks or strictures (12%); abdominal hernias (7%); infections (6%) and pneumonia (4%). The overall death rate in 180 days following surgery in specialist centres is 0.2%.
|
|
Maintenance of weight loss |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
Weight fluctuation (yo-yo dieting) may be harmful. Once a patient has lost weight, it is important to follow up the patient and monitor diet. Ongoing follow up with regular weighing and ongoing dietary advice, has been shown to help sustain weight loss.
Key points
|
|
References |
|---|
|
TOPAbstractThe GP curriculum, diet...Barriers to a healthy...The role of the...The ideal dietMeasurement and classification...Causes of and risk...Health risks of obesityManagement of obese patientsMaintenance of weight lossReferences |
|---|
-
An approach to weight management in children and adolescents (2-18 years) in primary care. (2003) nationalobesityforum.org.uk/images/stories/W_M_guidelines/Children_and_adolescents.pdf [date accessed 01.04.08].
Bahamondes L, Del Castillo S, Tabares G, Arce XE, Perrotti M, Petta C. Comparison of weight increase in users of depot medroxyprogesterone acetate and copper IUD up to 5 years. Contraception (2001) 64(4):223–5.[CrossRef][Web of Science][Medline]
British Nutrition Foundation. Website: www.nutrition.org.uk.
Counterweight project. Website: www.counterweight.org.
Encinosa WE, Bernard DM, Chen C-C, Steiner CA. Healthcare utilization and outcomes after bariatric surgery. Medical Care (2006) 44(8):706–712.[CrossRef][Web of Science][Medline]
Food Standards Agency. Website: www.eatwell.gov.uk.
Gallo MF, Lopez LM, Grimes DA, Schulz KF, Helmerhorst FM. Combination contraceptives: effects on weight. Cochrane Database of Systematic Reviews (2006) Issue 1. Art. No.: CD003987. DOI: 10.1002/14651858.CD003987.pub2.
Guidelines on the management of adult obesity and overweight in primary care. (2002) nationalobesityforum.org.uk/images/stories/W_M_guidelines/NOF_Adult_Guildelines_Feb_06.pdf [date accessed 01.04.08].
Manson JE, Willet WC, Stampfer MJ. "Bodyweight and mortality among women". New England Journal of Medicine (1995).
Managing obesity in primary care training resource. nationalobesityforum.org.uk/content/blogcategory/62/133/ [date accessed 01.04.08].
National Audit Office. Tackling obesity in England (2001) www.nao.org.uk/publications/nao_reports/00-01/0001220.pdf [date accessed 01.04.08].
National obesity forum. Website: www.nationalobesityforum.org.
Obesity care pathway and toolkit. nationalobesityforum.org.uk/content/blogcategory/18/170/ [date accessed 01.04.08].
NICE. Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children. (2006) www.nice.org.uk/guidance/index.jsp?action=folder&;o=30362 [date accessed 01.04.08].
Office for National Statistics. The National Diet & Nutrition Survey: adults aged 19 to 64 years. (2004) www.statistics.gov.uk/downloads/theme_health/NDNS5_V2.pdf [date accessed 01.04.08].
RCGP. Curriculum statement 5: Healthy people. www.rcgp-curriculum.org.uk/pdf/curr_5_Healthy_people.pdf [date accessed 01.04.08].
RCGP. Curriculum statement 15.2: Digestive problems. www.rcgp-curriculum.org.uk/pdf/curr_15_2_Digestive_problems.pdf [date accessed 01.04.08].
SIGN. Management of obesity in children and young people. (2003) www.sign.ac.uk/pdf/sign69.pdf [date accessed 01.04.08].
Simon C. Oxford General Practice Library: Gastrointestinal problems (2008) Oxford: Oxford University Press.
Wadden TA, Berkowitz RI, Womble LG, Sarwer DB, Phelan S, Cato RK, Hesson LA, Osei SY, Kaplan R, Stunkard AJ. Randomized trial of lifestyle modification and pharmacotherapy for obesity. New England Journal of Medicine (2005) 353(20):2111–2120.
Williamson DF, Madans J, Anda RF, Kleinman JC, Giovino GA, Byers T. Smoking cessation and severity of weight gain in a national cohort. New England Journal of Medicine (1991) 324(11):739–45.[Abstract]
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||