Obesity
Questionnaire/history:
PMH: FH? - Overweight/obesity? - Diabetes? - Coronary heart disease? DH? SH? - Lifesyle?
- Work activities?
- Leisure activities?
- Diet?
- Exercise?
- Alcohol?
- Smoking?
Examination:
Height?
Weight?
BMI?
Waist circumference?
WHR? BP (with appropriately sized arm cuff)?
Investigations: Preferably fasting samples: Glucose? Lipid profile? Depending on patient's history and examination: Liver function? Thyroid function?
Diagnosis:
Healthy weight: BMI of 18.5-24.9 kg/m2
Overweight: BMI of 25-29.9
Obesity class 1: BMI of 30-34.9
Obesity class 2: BMI of 35-39.9
Obesity class 3: BMI of 40 or more
Lower BMI thresholds in people with a
- Middle Eastern - South Asian, Chinese, other Asian,
- Black African or African-Caribbean family background as prone to central adiposity and the cardiometabolic risk occurring at lower BMI:
Overweight — BMI 23 to 27.4 kg/m2
Obesity — BMI 27.5 kg/m2 or above
Obesity classes 2 and 3 — reduce the BMI thresholds by 2.5 kg/m2
Caution in:
Adults with high muscle mass because it may be a less accurate measure of central adiposity in this group.
People aged over 65 years, taking into account comorbidities, conditions that may affect functional capacity, and the possible protective effect of having a slightly higher BMI when older
BMI < 35 kg/m2: waist-to-height ratio (WHR) as well as BMI as a practical estimate of central adiposity: Healthy central adiposity — 0.4 to 0.49, indicating no increased health risks. Increased central adiposity — 0.5 to 0.59, indicating increased health risks. High central adiposity — 0.6 or more, indicating further increased health risks.
This classification can be used for people with a BMI under 35 kg/m2 of both sexes and all ethnicities, including adults with high muscle mass
Higher levels of adiposity are associated with health risks such as type 2 diabetes, hypertension or cardiovascular disease
BMI Waist circumference Low High Very high Female < 80 cm 80-88 cm > 88cm Male < 94 cm 94-102 cm > 102 cm 25-29.9 No increased risk Increased risk High risk 30-34.9 Increased risk High risk Very high risk
≥ 35 Very high risk regardless of WHR
Management:
Asked for permission before talking in a sensitive manner about the degree of overweight, obesity and central adiposity? Information given about the severity of obesity and central adiposity and the impact this has on the risk of developing other long-term conditions (such as type 2 diabetes, cardiovascular disease, hypertension, dyslipidaemia, certain cancers, respiratory conditions, musuloskeletal conditions and other metabolic conditions such as non-alcoholic fatty liver disease)?
BMI 25–29.9 kg/m2 (overweight)?
Low waist circumference (less than 80 cm for women or less than 94 cm for men)?
Offered general advice on healthy weight and lifestyle?
Large waist circumference (80 cm or more for women or 94 cm or more for men)?
Offered structured advice regarding physical activity and diet?
Considered the use of behavioural interventions to achieve this aim?
Considered starting drug treatment in overweight people with a BMI of 27 kg/m2 with associated risk factors (such as type 2 diabetes, hypertension, or dyslipidaemia)?
Considered the need for referral to weight management services (tier 2 services) or specialist obesity services (tier 3 services)?
(See NICE guideline on Weight management: lifestyle services for overweight or obese adults)
BMI of 30–34.9 kg/m2 (obesity I)?
Offered structured advice regarding physical activity and diet?
Considered the use of behavioural interventions to achieve this aim?
Considered starting drug treatment in people with associated risk factors (such as type 2 diabetes, hypertension, or dyslipidaemia)?
Considered the need for referral for weight management services (tier 2 services) or specialist obesity services (tier 3 services)?
Recent-onset type 2 diabetes (diagnosed within a 10-year time frame) with a BMI of 30–34.9 kg/m2?
Consider an assessment for bariatric surgery as long as the person is also receiving or will receive specialist assessment (in a tier 3 service or equivalent)?Asian family origin?
Consider referral for an assessment for bariatric surgery for people at a lower BMI than other populations as long as they are also receiving or will receive specialist assessment (in a tier 3 service or equivalent)?
BMI of 35 kg/m2 or more (obesity II and obesity III):
Offered structured advice regarding physical activity and diet?
Considered the use of behavioural interventions to achieve this aim?
Considered starting drug treatment?
Considered the need for referral for bariatric surgery or endoscopic sleeve gastroplasty?
Criteria fulfilled for bariatric surgery?Recent-onset type 2 diabetes (diagnosed within a 10-year time frame) with a BMI of 35 kg/m2 or more?
Offered an expedited assessment for bariatric surgery as long as the person is also receiving or will receive specialist assessment (in a tier 3 service or equivalent)?
BMI > 50 kg/m2:
Bariatric surgery is the first-line option (instead of lifestyle intervention or drug treatment) when other interventions have not been effective?
Managed comorbidities that were identified during assessment?
Offer additional advice and support, as appropriate, including information on treatment targets?
Eg 5–10% reduction in body weight (or higher [for example more than 20%] in people with BMI of more than 35 kg/m2) with weekly weight loss of more than 1 kg?
Offer regular, non-discriminatory long-term follow-up by a trained professional?Behavioural interventions?
Self-monitoring of behaviour and progress?
Stimulus control?
Goal setting?
Slowing rate of eating?
Ensuring social support?
Problem-solving?
Assertiveness?
Cognitive restructuring (modifying thoughts)?
Reinforcement of changes?Relapse prevention?
Strategies for dealing with weight regain?
Advice on diet given?
Taken into account the person's food preferences and allowed for flexible approaches to reducing calorie intake
To eat a nutritionally balanced diet, which should include:
Five portions of a variety of fruit and vegetables each day
Meals based on starchy foods (for example bread, pasta, rice, and potatoes) — these should include high fibre varieties if possible
Moderate amounts of milk and dairy products — these should be low fat if possible
Moderate amounts of protein-rich foods (for example meat, fish, eggs, beans, and lentils)
Reduce the consumption of foods high in fat (especially saturated fat), sugar, and salt
Cook using methods which reduce fat (for example grilling and steaming)
Not exceed recommended levels of alcohol, as alcohol is high in calories
Practical ways to limit alcohol consumption may include replacing alcoholic drinks with non-alcoholic, sugar-free drinks and increasing the number of alcohol-free days (see Alcohol - problem drinking)
Do not use unduly restrictive and nutritionally unbalanced diets, because they are ineffective in the long term and can be harmful
Diets that are recommended for sustainable weight loss are:
Those with a 600 kcal/day deficit (that is, they contain 600 kcal less than the person needs to stay the same weight), or
Those which reduce calories by lowering the fat content (low-fat diets)
Consider low-calorie diets (800–1600 kcal/day), but be aware these are less likely to be nutritionally complete
Do not routinely use very-low-calorie diets (800 kcal/day or less) to manage obesity
Only consider these, as part of a multicomponent weight management strategy, if obesity and clinically assessed need to rapidly lose weight (for example if joint replacement surgery or fertility services are needed)
Ensure that the diet is nutritionally complete, is followed for a maximum of 12 weeks (continuously or intermittently)
Before starting a very-low-calorie diet as part of a multicomponent weight management strategy:
Consider counselling, and assess for eating disorders or other psychopathology to make sure the diet is appropriate
Discuss the risks and benefits of the dietExplain that it is not a long-term weight management strategy, and that regaining weight may happen and is not because of their anyone’s failure
Discuss the reintroduction of food following a liquid dietHave a long-term multicomponent strategy to help maintaining the weight after the use of a very-low-calorie dietEat a balanced diet in the long term, consistent with other healthy eating advice
See the 'Your Weight, Your Health' booklet produced by the Department of Health
Advice on physical activity given?
Consider:
Motivations and goals
Current physical fitness and ability
Preferences
Barriers to being physically active health status (for example a medical condition or a disability)
If appropriate:
Reduce the amount of time spent being inactive (for example watching television or using a computer)
Do at least 30 minutes of at least moderate intensity exercise on 5 days a week or more (this can be done in one session or split into a number of sessions each lasting at least 10 minutes); build up to these recommended levels
Recommended types of physical activity include:
Activities that can be incorporated into everyday life, such as gardening, brisk walking, or cycling (see NICE guideline on Walking and cycling)
Supervised exercise programmes (see NICE guideline on Exercise referral schemes)
Other activities (for example swimming, aiming to walk a certain number of steps each day, or stair climbing)
Set goals and adjust these as physical fitness improves
Take more exercise even if it does not lead to weight loss, because exercise has other health benefits, such as reducing the risk of coronary heart disease, stroke, cancer, and type 2 diabetes, it can also help to keep the musculoskeletal system healthy, promote mental wellbeing, and improve life expectancy
To prevent obesity, most people may need to do 45–60 minutes of moderate-intensity activity a day, especially if they do not reduce their energy intake
People who have been obese and have lost weight may need to do 60–90 minutes of activity a day to avoid regaining weight
A pedometer may be useful for motivation and to help monitor the activity levelsIf appropriate, one can gradually work towards a goal of 10,000 steps a day
See 'Your Weight, Your Health' booklet produced by the Department of Health
Drug treatment
Only to be considered once dietary, exercise and behavioural interventions have been started and evaluated
Orlistat
Licensed, in conjunction with a mildly hypocaloric diet, for adults aged between 18–75 years who meet one of the following criteria:
- BMI of 30 kg/m2 or more, or
- BMI of 28 kg/m2 or more with associated risk factors
Recommended dose is 120 mg capsule taken with water immediately before, during, or up to one hour after each main meal, if a meal is missed or contains no fat, the dose of orlistat should be omitted
Orlistat 60 mg capsules (Alli®) can be purchased over-the-counter from pharmacies and does not require a prescription
Discontinue treatment with orlistat after 12 weeks if no weight loss of at least 5% Rates of weight loss may be slower in people with type 2 diabetes, so less strict goals (for example a loss of more than 3% of their body weight in 12 weeks) may be appropriate
For people who have lost the recommended amount of weight, there is no restriction on how long orlistat may be prescribed
To stop taking orlistat and seek medical assistance if symptoms of hepatitis (yellowing skin and eyes, itching, dark-coloured urine, stomach pain and liver tenderness)(see Adverse effects)
See Prescribing information for information on the contraindications, cautions, adverse effects, and possible drug interactions of orlistat
Liraglutide (Saxenda®)
Glucagon-like peptide (GLP-1) receptor agonist
Licensed as an adjunct to a reduced-calorie diet and increased physical activity for weight management in adults with an initial - BMI of 30 kg/m2 or more (obese), or - 27 kg/m2 to less than 30 kg/m2 (overweight) in the presence of at least one weight-related comorbidity, such as dysglycaemia (prediabetes or type 2 diabetes mellitus), hypertension, dyslipidaemia, or obstructive sleep apnoeaTreatment should be discontinued after 12 weeks if no weight loss of at least 5%
NICE recommends liraglutide as an option for managing overweight and obesity alongside a reduced-calorie diet and increased physical activity in adults, only if:
BMI of at least 35 kg/m2 (or at least 32.5 kg/m2 for members of minority ethnic groups known to be at equivalent risk of the consequences of obesity at a lower BMI than the white population) and
non-diabetic hyperglycaemia (haemoglobin A1c level of 42 mmol/mol to 47 mmol/mol [6.0% to 6.4%] or a fasting plasma glucose level of 5.5 mmol/litre to 6.9 mmol/litre) and
high risk of cardiovascular disease based on risk factors such as hypertension and dyslipidaemia and
it is prescribed in secondary care by a specialist multidisciplinary tier 3 weight management service
Semaglutide (Wegovy®)
Glucagon-like peptide (GLP-1) receptor agonist
Licensed as an adjunct option for specialist multidisciplinary weight management services who are offering weight loss management in addition to a reduced-calorie diet and increased physical activity in adults
Only licensed within specialist weight management services, and the person has at least one weight-related comorbidity and a:
- BMI of at least 35.0 kg/m2, or
- BMI of 30.0 kg/m2 to 34.9 kg/m2 and they meet the criteria for referral to specialist weight management services (see the section on Referral for more information)
NICE advised that lower BMI thresholds (usually reduced by 2.5 kg/m2) should be used for people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean family backgrounds
NICE also advised that clinicians should consider stopping semaglutide if less than 5% of the initial weight has been lost after 6 months of treatment
Semaglutide should be used for a maximum of 2 years
Tirzepatide (Mounjaro®)
Dual agonist for the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (GLP-1) receptors
Licensed for weight management, including weight loss and weight maintenance, as an adjunct to a reduced-calorie diet and increased physical activity in adults with an initial
- BMI of at least 30 kg/m2, or
- 27 kg/m2 to 30 kg/m2 in the presence of at least one weight-related comorbid condition such as hypertension, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease, prediabetes, or type 2 diabetes mellitus If patients have been unable to lose at least 5% of their initial body weight 6 months after titrating to the highest tolerated dose, a decision is required on whether to continue treatment, taking into account the benefit/risk profile in the individual patient Scottish Medicines Consortium (SMC): BMI >30 kg/m2 or >=27 kg/m2 (a lower BMI cut-off may be more appropriate for members of minority ethnic groups) + 1 weight-related comorbidity
NHSE definition of qualifying co-morbidities: established CVD, hypertension requiring blood pressure lowering treatment, dyslipidaemia treated with lipid-lowering treatment or high LDL/TG or low HDL, OSA (confirmed by a sleep clinic), T2DM
Delayed gastric emptying for tirzepatide may have a greater impact on the absorption of oral contraceptives compared to other GLP-1RA medicines
However, due to limited information available about the effect of tirzepatide on the pharmacokinetics and efficacy of oral contraceptives in individuals with obesity or who are overweight, reduced efficacy cannot be excluded Since this reduced efficacy of oral contraceptives cannot be excluded, it is advised that people taking tirzepatide should switch to a non-oral contraceptive method or add a barrier method of contraception when the drug is started (for 4 weeks) and after each dose escalation (for 4 weeks). Considering changing to IUS or increase the dose of progestogen at initiation or dose change for 4 week (no guidance on specific doses given (eg +100mg).
Unscheduled bleeding: If bleeding continues despite modification of progestogen dose, given that obesity is a risk factor for endometrial cancer, and women will be at higher risk earlier investigation prudent.
Available data where the drug was used in early to mid-stage pregnancy does not appear to show adverse maternal or infant outcomes, but a 'wash-out' period before planned pregnancy of one month is recommended.
Bariatric surgery
To be offered to adults as a referral for a comprehensive assessment by specialist weight management services providing multidisciplinary obesity management to see whether bariatric surgery is suitable if:
- BMI ≥ of 40 kg/m2 , or
- BMI 35-40 kg/m2 with a significant health condition that could be improved if they lost weight (for example type 2 diabetes, hypertension, or severe mobility problems)
- Agreement to the necessary long-term follow-up after surgery (for example, life-long reviews)
Referral consideration for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background using a lower BMI threshold (reduced by 2.5 kg/m2) (This accounts for the fact that these groups are prone to central adiposity and their cardiometabolic risk occurs at a lower BMI)
For people with recent-onset type 2 diabetes (diagnosed within a 10-year time frame):
Expedited assessment if BMI of ≥ 35 kg/m2 (30–34.9 kg/m2) as long as an assessment in a specialist weight management service is received or will be received
Expedited assessment for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background with recent-onset type 2 diabetes using a lower BMI threshold (reduced by 2.5 kg/m2)
Referral criteria
Tier 2 services:
BMI ≥ 30 kg/m2
Lower BMI (for example 27.5kg/m2 or more) if black African, African-Caribbean, and Asian family originWhere there is capacity:BMI of 25 kg/m2 or more (23 kg/m2 or more for those of black African, African-Caribbean, and Asian family origin)
Where local provision is not available, directing to commercial services which adhere to the National Institute for Health and Care Excellence (NICE) guidance on Weight management: lifestyle services for overweight or obese adults
Tier 3 services:
Underlying causes of overweight and obesity need to be assessed
Complex disease that cannot be managed adequately in tier 2 (for example, additional support needed because of learning disabilities)
Conventional treatment has failed in primary or secondary care
Drug treatment is being considered for a person with a BMI of more than 50 kg/m2Specialist interventions (such as a very-low-calorie diet) may be neededSurgery is being considered
Treatment with liraglutide (Saxenda®) is being considered
Bariatric surgery
Aims and benefits of treatment
Aim: 5–10% reduction in body weight (or higher [for example more than 20%] in people with body mass index [BMI] of more than 35 kg/m2); weekly weight loss should be no more than 1 kg
Benefits of modest weight loss with regard to comorbidities and disease risk, particularly if the person is obese
Gaining more weight may increase risks to health
Excess weight can be problematic in terms of comorbidities and the chance of developing complications
Need for long-term behavioural changes, including adherence to advice on diet and physical activity
Distinction between losing weight and maintaining weight loss, and the importance of developing skills for both
Change from losing weight to maintenance typically happens after 6–9 months of treatmentWeight cycling, defined by repeated loss and regain of body weight, may be linked to increased risk for hypertension, dyslipidaemia, gallbladder disease, psychological distress, and depression.Physical activity alone without dietary changes are not effective for weight loss
Reference(s):
Information for patient/carer(s):
Department of Health: Your Weight, Your Health NHS Health A to Z: Obesity
NHS Helath A to Z: Weight loss surgery Voluntary organisations and support groups: British Obesity Society (BOS) HOOP UK