Obesity is a chronic, relapsing and multifactorial disease, rather than simply a consequence of insufficient willpower. Its management should therefore be long-term, individualised and focused on improving health, physical function, quality of life and psychological wellbeing—not only on reducing body weight. Communication should be respectful, non-judgemental and free from weight stigma. (World Health Organisation)
Treatment usually combines:
Before discussing weight, healthcare professionals should ask the patient for permission and explore their priorities, previous experiences and readiness for treatment.
The clinical assessment should include:
BMI is a useful screening measure but does not directly measure body-fat distribution. Central adiposity and cardiometabolic risk may occur at lower BMI thresholds in some ethnic groups. (NICE)
Important comorbidities include type 2 diabetes, hypertension, dyslipidaemia, cardiovascular disease, obstructive sleep apnoea, metabolic fatty liver disease, osteoarthritis, reproductive problems and psychological disorders. These conditions should be treated as soon as they are identified; treatment should not be delayed until weight loss has occurred. (NICE)
Goals should be realistic, measurable and agreed with the patient. Relevant outcomes include:
A loss of approximately 5–10% of initial body weight can improve blood glucose, blood pressure, triglyceride levels and other weight-related health problems. However, benefits may also occur without major weight loss—for example through improved nutrition and increased physical activity. (NIDDK)
Nutrition
A sustainable dietary plan should create an energy deficit while remaining nutritionally balanced. The specific dietary pattern should be adapted to the patient’s preferences, culture, financial circumstances, comorbidities and ability to maintain it.
Possible approaches include reducing portion sizes, limiting energy-dense and highly processed foods, replacing sugar-sweetened drinks, increasing vegetables and fibre-rich foods, and selecting appropriate sources of protein and healthy fats. No single dietary pattern is suitable for everyone.
Highly restrictive or nutritionally unbalanced diets should be avoided. Low-energy and very-low-energy diets should generally be used only for limited periods, with professional supervision and as part of a broader long-term treatment programme. (NICE)
Physical Activity
Physical activity should be increased gradually according to the patient’s fitness, mobility, preferences and medical conditions. Suitable activities may include walking, cycling, swimming, resistance training, supervised exercise and increased movement during everyday life.
Exercise provides cardiovascular, metabolic, musculoskeletal and psychological benefits even when it does not produce substantial weight loss. Reducing sedentary time is also important. (NICE)
Behavioural and Psychological Support
Behavioural treatment may include:
Barriers such as chronic stress, mental-health problems, neurodevelopmental conditions, physical disability, financial limitations and cultural circumstances should be actively addressed. Regular feedback and follow-up improve engagement. (NICE)
Anti-obesity medication may be considered when lifestyle and behavioural interventions alone have not produced sufficient improvement, or when the patient’s degree of obesity and associated health risks justify additional treatment.
Medication must be used in combination with a reduced-calorie diet, increased physical activity and behavioural support, rather than as a replacement for these measures. The choice depends on local approval criteria, BMI, comorbidities, contraindications, side effects, patient preferences, cost and availability. (NICE)
Examples of medicines used for weight management include:
WHO guidance conditionally supports the long-term use of liraglutide, semaglutide and tirzepatide in adults with obesity, excluding pregnancy, as part of comprehensive lifelong care. Availability and prescribing rules vary between countries. (n)
Patients should be monitored regularly for:
Weight regain may occur after medication is discontinued, so patients need continued behavioural and clinical support.
Metabolic or bariatric surgery is an effective treatment option for appropriately selected people with severe obesity or significant obesity-related complications.
Referral criteria differ between healthcare systems. For example, NICE recommends assessment for many adults with a BMI of at least 40 kg/m², or 35–39.9 kg/m² with a significant weight-related condition. International ASMBS/IFSO guidance recommends surgery at BMI 35 kg/m² or above regardless of comorbidity and consideration at BMI 30–34.9 kg/m² when metabolic disease is present. Lower thresholds may be appropriate for populations who develop cardiometabolic complications at lower BMI levels. (NICE)
Common procedures include sleeve gastrectomy and Roux-en-Y gastric bypass. Selection requires multidisciplinary medical, nutritional, psychological and surgical assessment.
After surgery, long-term care must include:
(NICE)
Obesity management should be treated as ongoing care. Follow-up should review weight trajectory, waist measurements, comorbidities, medications, nutrition, physical activity, mental health and functional ability.
Weight regain is common and should not be described as personal failure. It may indicate the need to intensify behavioural support, restart or change medication, assess suitability for surgery, or address new medical, psychological or social factors. (NICE)
Children and adolescents require age-appropriate, family-based, multidisciplinary treatment that supports healthy growth and avoids overly restrictive diets. Medication and surgery should be managed through specialist paediatric services.
Pregnancy requires a separate approach. Weight-loss medicines are generally not used during pregnancy, and pregnancy plans should be discussed before pharmacological or surgical treatment. Older adults also require attention to muscle mass, nutritional status, frailty and physical function.
Key Message
Effective obesity management is person-centred, multidisciplinary and long-term. Lifestyle and behavioural interventions form the foundation, while medication and metabolic surgery may be added according to the severity of obesity, associated complications, treatment response and patient preferences. Success should be assessed by improvements in health and quality of life—not solely by the number on the scale.