PassFinals
Endocrinology & Metabolic

Obesity

Obesity is chronic excess adiposity that impairs health, shaped by biological, environmental, social and genetic factors; assess risk beyond BMI, treat complications and offer sustained behavioural support, escalating to NICE-approved medicines or bariatric services when eligible.

In a nutshell

Obesity is chronic excess adiposity that impairs health. Assess central adiposity and complications as well as BMI; offer sustained behavioural weight-management support to everyone, treat diabetes/CVD/sleep and musculoskeletal complications, and consider NICE-approved medicines or bariatric assessment when eligibility criteria are met.

Classic presentation

An adult with central adiposity and obesity-related type 2 diabetes, hypertension, daytime sleepiness or joint disease identified during a complication review.

Key points

  • BMI is a screening/classification tool; central adiposity and ethnicity alter cardiometabolic risk.
  • Obesity is biologically defended and relapsing, so maintenance support matters.
  • Behavioural weight management is foundational and continues alongside medicines or surgery.
  • Semaglutide and tirzepatide are NICE options only within defined eligibility and support pathways.
  • Screen for eating disorders, sleep apnoea, diabetes, hypertension, dyslipidaemia, MASLD and mental-health impact.

First-line investigation

BMI with appropriate central-adiposity measurement, blood pressure, HbA1c/glucose, lipids, renal/liver assessment and complication review.

Management

Find urgent complications

  • Escalate severe breathlessness/hypoventilation, chest pain, diagnostic hyperglycaemia, severe hypertension, pancreatitis symptoms or acute mental-health risk.2,3

Assess adiposity and health impact

  • Measure BMI and appropriate central adiposity, then assess cardiometabolic, respiratory, musculoskeletal, reproductive, psychological and eating-related complications.1

Start behavioural treatment

  • Offer sustained dietary, physical-activity and behaviour-change support, with relapse planning and continued maintenance.1

Treat complications

  • Manage diabetes, CVD risk, lipids, blood pressure, MASLD, sleep apnoea, CKD and musculoskeletal disease through the relevant NICE pathways.2,3,1

Use specialist options

  • Consider eligible NICE weight-management medicines or bariatric assessment after behavioural treatment has started, with BNF checks and specialist support.1,4,5,6

Maintain benefit

  • Review weight trajectory, complications, nutritional and psychological health, treatment effects and relapse risk long term.1,2

Exam traps

  • Do not use BMI alone to estimate cardiometabolic risk.
  • Do not prescribe weight-management medicine without checking the current NICE eligibility pathway and BNF.
  • Stopping an effective medicine can be followed by weight regain; this is a maintenance issue, not a reason to omit follow-up.
  • Rapid severe weight gain, Cushingoid features, early-onset hyperphagia or major psychological symptoms need a different assessment.
  • Treat established diabetes, CVD, hypertension, sleep apnoea and CKD through their own pathways.

Illustrations

Waist circumference measurementA tape measure positioned horizontally around the abdomen to assess central adiposity and cardiometabolic risk alongside BMI.Petr Kratochvil, Wikimedia Commons · CC0

Key sources

  1. NICE NG246: Overweight and obesity management (Current NICE recommendations on assessment of overweight, obesity and central adiposity, behavioural interventions, weight-management medicines and bariatric surgery; current guidance accessed 4 August 2026.)
  2. NICE NG238: Cardiovascular disease: risk assessment and reduction, including lipid modification (Current NICE CVD-risk and lipid pathway used for obesity-related cardiovascular prevention; accessed 4 August 2026.)
  3. NICE NG28: Type 2 diabetes in adults: management (Current NICE type 2 diabetes pathway used for obesity-related dysglycaemia and cardiorenal risk; current page accessed 4 August 2026.)
  4. NICE TA875: Semaglutide for managing overweight and obesity (NICE technology appraisal recommendations for semaglutide in eligible adults as an adjunct to reduced-calorie diet and increased physical activity; accessed 4 August 2026.)
  5. NICE TA1026: Tirzepatide for managing overweight and obesity (NICE technology appraisal recommendations for tirzepatide in eligible adults as an adjunct to diet and physical activity; accessed 4 August 2026.)
  6. British National Formulary (BNF) (Current UK prescribing information for orlistat, semaglutide, tirzepatide, other weight-management medicines and complication treatments; product-specific dose, contraindications, interactions and monitoring must be checked at the point of care; accessed 4 August 2026.)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.