Endocrine & Metabolic · Full case
Obesity
Obesity · Clinical Reasoning Framework v2
GP & SCA · NICE CG189 · BMI & waist · Secondary causes · Comorbidity screen · Tiered weight management · GLP-1 · Bariatric surgery
BMI + waist + ethnicityClassify with BMI (overweight 25–29.9; obesity class 1 30–34.9; class 2 35–39.9; class 3 ≥40) AND waist circumference. Lower the thresholds by ~2.5 kg/m² for South Asian, Chinese and other high-risk ethnicities, where cardiometabolic risk occurs at lower BMI
It's a disease, not a failingObesity is a chronic, relapsing, multifactorial condition — genetic, biological, psychological, social and environmental — not simply a lack of willpower. Stigmatising language drives disengagement; use respectful, person-first communication and raise the topic with permission
Screen the complicationsAssess for type 2 diabetes (HbA1c), hypertension, dyslipidaemia, NAFLD, obstructive sleep apnoea, osteoarthritis, subfertility/PCOS, depression and cardiovascular risk — obesity rarely travels alone
Exclude secondary causesConsider hypothyroidism, Cushing's syndrome, hypothalamic causes, PCOS and drug causes (steroids, some antipsychotics, insulin/sulfonylureas, some antidepressants) — especially with rapid gain or atypical features
Tiered weight managementStepped pathway: Tier 1 universal/lifestyle; Tier 2 community weight-management programmes; Tier 3 specialist multidisciplinary services (incl. pharmacotherapy); Tier 4 bariatric surgery. Match the tier to BMI, comorbidity and previous attempts
5–10% changes outcomesA 5–10% weight loss meaningfully improves blood pressure, glycaemia, lipids, sleep apnoea and joint symptoms. Set realistic, agreed, sustainable goals — not an idealised "target weight"
GLP-1 eraPharmacotherapy: orlistat; and GLP-1 receptor agonists (e.g. liraglutide, semaglutide) and dual agonists where criteria are met — usually within specialist/Tier 3 services and time-limited. They are adjuncts to lifestyle change, not a replacement
Bariatric thresholdsConsider bariatric surgery referral at BMI ≥40, or ≥35 with a significant comorbidity (e.g. type 2 diabetes), after Tier 3; lower thresholds apply for some ethnicities and for recent-onset type 2 diabetes. It is the most effective durable treatment for severe obesity
📋 Clinical Stem — Obesity
A 44-year-old man who has "tried everything", feels judged by previous appointments, and asks directly about "the weight-loss injections" he has seen online
Daniel Price, 44, a delivery driver, books in to ask about "those weight-loss jabs." His BMI is 38; his waist is 118cm. He has tried multiple diets over the years, losing and regaining weight each time, and says he feels like a failure and that doctors "just tell me to eat less and move more." He has borderline-high blood pressure, snores heavily and feels unrefreshed in the morning, and his father had type 2 diabetes and a heart attack at 55. He works long hours sitting in a van, eats on the go, and his mood is low. He is hoping a medication will finally work.
This stem tests the ability to: raise and discuss weight respectfully and without stigma (with permission), recognising obesity as a chronic disease rather than a willpower problem; assess holistically — BMI and waist (adjusted for ethnicity), drivers, previous attempts, mental health, and a comorbidity screen (type 2 diabetes, hypertension, dyslipidaemia, NAFLD, OSA, cardiovascular risk); exclude secondary and drug causes where indicated; apply the tiered weight-management pathway and set realistic, agreed goals; explain the place of pharmacotherapy (orlistat, GLP-1 agonists) and bariatric surgery honestly, including eligibility and that they are adjuncts to lifestyle change; and screen for OSA and low mood. The SCA challenge is responding to the request for "the injections" with an honest, non-dismissive, shared plan, and repairing the sense of being judged.
Scenario A — Obesity + comorbidities (this stem) BMI 38, central adiposity, ?OSA, high cardiovascular risk. Holistic assessment, comorbidity screen, tiered pathway, realistic goals, discuss GLP-1/Tier 3 and bariatric criteria; OSA referral; mood support.
Scenario B — Secondary cause suspected Rapid gain, central obesity with striae/proximal weakness (Cushing's), cold intolerance/fatigue (hypothyroid), or a culprit drug. Targeted investigation/medication review before attributing to lifestyle alone.
Scenario C — Disordered eating Binge eating, restrict–binge cycles, emotional eating, or features of an eating disorder. Address the eating disorder; weight-loss-only approaches can be harmful — psychological input.
Scenario D — Bariatric candidate BMI ≥40 (or ≥35 with type 2 diabetes), after Tier 3, motivated and fit for surgery. Discuss benefits/risks, lifelong follow-up and supplementation; refer to specialist service.
Scenario E — Childhood obesity Use BMI centiles; involve the family; consider safeguarding where neglect is a concern; screen comorbidities; specialist referral for severe/complex cases.
Key variables to adapt for BMI class & ethnicity-adjusted thresholds; waist/central adiposity; comorbidities (T2DM, HTN, dyslipidaemia, NAFLD, OSA, OA, PCOS/subfertility); secondary/drug causes; mental health and disordered eating; previous attempts and readiness; tier/eligibility for pharmacotherapy and surgery; social/occupational drivers; stigma and the therapeutic relationship; children (centiles, safeguarding).
Steps:
1
Step 1
History — Permission & Drivers · Comorbidities · Secondary Causes · ICE
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The history does three things: it builds a respectful, non-stigmatising understanding of the drivers and previous attempts; it screens for the comorbidities that obesity brings (which make this consultation about cardiovascular and metabolic health, not just weight); and it considers secondary and drug causes. Daniel arrives feeling judged and wanting a medication — the relationship is the first clinical task.
🎓 SCA framing — ask permission, drop the blame
"Thanks for coming in about this — it takes something to raise it. Before we go further, would it be okay to talk about weight and health together? And I want to say up front: weight isn't about willpower, it's a genuine medical condition, and I'm here to help, not to judge."
Daniel expects to be told to "eat less, move more." Asking permission and explicitly naming obesity as a disease repairs the therapeutic relationship and makes the rest of the consultation possible. The "injections" request is honoured as a legitimate option to discuss, not dismissed.
1A — Drivers, attempts, comorbidities and causes
1B — Red flags / things not to miss
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Red Flags — when weight is a symptom, or carries danger
| Red flag | Why it matters | Action |
|---|---|---|
| Secondary endocrine cause — Cushing's, hypothyroidism, hypothalamic | Treatable underlying disease; missing Cushing's (striae, proximal myopathy, hypertension, diabetes) has serious consequences. | Targeted investigation (TFTs, overnight dexamethasone/cortisol); endocrinology if positive |
| Obstructive sleep apnoea | Untreated OSA causes daytime sleepiness (occupational risk — Daniel drives), hypertension, cardiovascular disease and accidents. | Epworth score; sleep study referral; DVLA advice if sleepiness affects driving |
| Disordered eating / eating disorder | A weight-loss-only approach can entrench or worsen an eating disorder; binge eating disorder needs specific treatment. | Assess; psychological/eating-disorder service; treat the disorder first |
| Severe complications — uncontrolled diabetes, severe OSA, decompensated comorbidity | May need urgent treatment and specialist (Tier 3/4) input. | Treat complications; specialist weight-management/relevant team |
| Mental health crisis / very low mood | Depression compounds obesity and impairs engagement; risk must be assessed. | Assess mood/risk; treat depression; support |
| Child with rapid weight gain / safeguarding concern | Severe childhood obesity may reflect a syndrome or, occasionally, neglect; needs centile-based assessment and sometimes safeguarding. | BMI centiles; family approach; specialist referral; safeguarding if indicated |
1C — ICE
💭 Ideas
"What do you think has made it so hard — and what do you think would actually help?"
Daniel believes he has "failed" and that medication is the answer. Surfacing his model lets you reframe repeated regain as the biology of a chronic relapsing condition (not personal failure) and to position medication accurately — as one effective tool among several, working best alongside change.
😟 Concerns
"Has coming about this been difficult — have you felt judged before?"
His concern is being lectured and dismissed. Acknowledging previous poor experiences directly, and committing to a non-judgmental partnership, repairs the relationship and is essential for engagement and follow-through.
🎯 Expectations
"You're hoping the injections will help — can I be honest about what they can and can't do, and who can have them?"
Naming the expectation lets you be honest about GLP-1 eligibility (often Tier 3/specialist, criteria-based, time-limited), that they are adjuncts to lifestyle change, and that regain is common when stopped — while offering a realistic route, so he leaves with a plan rather than disappointment.
1D — Psychosocial context
🚫 Undoing "eat less, move more"
Acknowledge the simplistic advice he's had and explain the biology of weight regain — appetite hormones defend a higher set-point.
"You've been told to eat less and move more, and it hasn't held — that's not because you failed, it's because your body actively defends its weight. That's exactly why this is a medical condition and why we sometimes need medical tools."💉 The injection conversation
Be honest: GLP-1s are effective but criteria-based, usually specialist/time-limited, adjuncts to lifestyle, with regain on stopping.
"The injections can genuinely help and I'm glad you asked. They work best alongside changes, they're usually arranged through a specialist service with certain criteria, and the weight tends to come back if you stop — so we'd plan it properly, not as a quick fix."🎯 Realistic goals
A 5–10% loss meaningfully improves health; reframe success away from an idealised number.
"We don't need a dramatic number. Losing even 5–10% would noticeably improve your blood pressure, your sleep and your energy — and that's a realistic, lasting target to aim for together."🧠 Mood & the cycle
Low mood and weight feed each other; treating mood supports the weight work.
"You mentioned feeling low — that often goes hand in hand with this and can make changes harder. Let's look after your mood too, because it'll help everything else."🎓 SCA Checkpoint — Step 1TasksRelating to OthersGlobal Skills
Key phrases that score
"Would it be okay to talk about weight and health together? Weight isn't about willpower — it's a medical condition." — permission + reframe.
"You snore and wake unrefreshed — I'd like to check for sleep apnoea." — picks up OSA.
"The injections can help, but they're usually arranged through a specialist service with criteria and work best alongside changes." — honest about GLP-1.
Deductions
- Lecturing / "eat less, move more"; stigmatising language
- Not screening comorbidities (T2DM, OSA, cardiovascular risk) or secondary causes
- Either refusing the GLP-1 request flatly or promising it uncritically
- Missing low mood / disordered eating
🔴 Red
Stigmatising/dismissive; no comorbidity or OSA screen; no permission; GLP-1 handled poorly; mood ignored
🟠 Amber
Respectful; some assessment; comorbidity screen partial; tier/medication discussed vaguely; ICE partial
🟢 Green
Permission + chronic-disease reframe; drivers & previous attempts explored; comorbidity + OSA + mood screened; secondary causes considered; honest GLP-1/tier discussion; realistic agreed goals; ICE all three
2
Step 2
Triage — Urgent Comorbidity · Specialist Tier · Routine Lifestyle
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Obesity itself is a chronic-care, not an emergency, presentation — but its complications can be urgent, and severity/BMI determines the tier of service. Triage means treating the dangerous comorbidity (uncontrolled diabetes, severe OSA), matching the management tier to BMI and comorbidity, and recognising disordered eating or mental-health crisis.
🔴 Urgent
Address now
Comorbidity / risk- Uncontrolled/symptomatic diabetes or cardiovascular diseaseTreat per pathway; don't wait for weight loss
- Severe OSA with sleepinessSleep referral; DVLA advice if driving impaired
- Mental-health crisis / eating disorderMental-health / eating-disorder service
🟠 Specialist tier
Tier 3 / 4
By BMI & comorbidity- Tier 3 specialist weight managementComplex/severe obesity; pharmacotherapy; pre-surgery
- Bariatric (Tier 4)BMI ≥40, or ≥35 with comorbidity, after Tier 3
- Secondary causeEndocrinology if Cushing's/other
🟢 Routine
Tier 1–2
Primary care & community- Lifestyle / behavioural supportDiet, activity, sleep, agreed goals
- Community weight-management programmeTier 2 referral
- Comorbidity screening & monitoringHbA1c, lipids, BP, LFTs
🎓 SCA Checkpoint — Step 2Tasks
Triage rationale
"Your BMI and the snoring and blood pressure mean two things: let's check and treat those health risks now, and let's get you into a proper weight-management programme — and we can talk about whether you'd meet the criteria for medication or, down the line, surgery."
Deductions
- Ignoring urgent comorbidity while focusing only on weight
- Not matching the tier to BMI/comorbidity
3
Step 3
Examination — BMI & Waist · BP · Comorbidity & Secondary-Cause Signs
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Measure objectively (BMI and waist, interpreted with ethnicity in mind), check blood pressure, and look for the signs of comorbidity and of a secondary cause.
🎓 SCA Checkpoint — Step 3TasksGlobal Skills
Narration that scores
"I'll measure your height, weight and waist and check your blood pressure, and have a quick look for any signs that point to a treatable cause — that helps me tailor the plan to you."
Deductions
- Not measuring waist / using ethnicity-adjusted thresholds
- Missing signs of a secondary cause or comorbidity
4
Step 4
Investigations — Comorbidity Screen · Secondary Causes · OSA
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Investigations quantify cardiometabolic risk, screen for the common complications, and exclude secondary causes where suspected.
🎓 SCA Checkpoint — Step 4Tasks
Key reasoning
"I'd like to check your sugar, cholesterol, liver and kidney function, and screen for sleep apnoea given the snoring — and, because of the family history, work out your heart-risk score."
Deductions
- No comorbidity screen / cardiovascular risk assessment
- Not screening OSA in a sleepy snorer who drives
- Over-investigating for rare causes with no indication
5
Step 5
Diagnosis — Classify Severity · Complications · Drivers
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The "diagnosis" is a formulation: severity (BMI class, ethnicity-adjusted, with central adiposity), the complications present, any secondary/drug contributor, and the personal drivers — because this drives the tier and the modality.
🚩 The formulation, not just the BMI
Obesity management fails when it is reduced to a single number and a single instruction. The useful "diagnosis" names the severity, the complications to treat, any reversible contributor, the drivers, and the patient's readiness — which together select the tier (lifestyle → community → specialist → surgery) and the modality. For Daniel: class 2 obesity with central adiposity, likely OSA, raised cardiovascular risk and low mood — a man who needs comorbidity treatment, a structured programme, a realistic goal, an honest conversation about GLP-1 eligibility, and his mood addressed.
🎓 SCA Checkpoint — Step 5Tasks
Explaining it plainly
"Your weight is in a range we'd call obesity, and it's bringing some health risks — your blood pressure, your sleep, and your future diabetes and heart risk. The good news is that even a modest, lasting loss improves all of those, and there are several tools we can use together."
Deductions
- Reducing it to BMI alone with no complication/driver formulation
- Missing disordered eating that changes the approach
6
Step 6
Referral — Tier 2/3 · Bariatric (Tier 4) · OSA · Endocrine · Mental Health
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Referral follows the tiered pathway and the comorbidities: community programmes (Tier 2), specialist weight management (Tier 3, including pharmacotherapy), bariatric surgery (Tier 4) by criteria, and the relevant specialty for complications and secondary causes.
🎓 SCA Checkpoint — Step 6Tasks
Eligibility, honestly
"The medication route is usually through a specialist weight-management service, and surgery becomes an option at higher BMIs or with diabetes after you've been through that service — so there's a clear pathway, and I'll start you on it."
Deductions
- Promising GLP-1/surgery without the criteria/pathway
- Not referring suspected OSA in a driver
7
Step 7
Management — Lifestyle · Behavioural · Pharmacotherapy · Surgery · Follow-up
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Management is a long-term, stepped, person-centred plan: lifestyle and behavioural change as the foundation, treatment of comorbidities, pharmacotherapy and surgery as tools within the tiered pathway, realistic agreed goals, and ongoing follow-up — because obesity is a chronic relapsing condition that needs continuity, not a one-off fix.
7A — The stepped plan
🎓 SCA Checkpoint — Step 7TasksRelating to OthersGlobal Skills
A plan that scores
"Here's the plan: a referral to a weight-management programme, some realistic changes we agree together, a check and treatment of your blood pressure and a sleep test, support for your mood, and a clear route to the specialist service where the medication is arranged — aiming first for a 5–10% loss. We'll keep reviewing; this is a long game, not a one-off."
Deductions
- Medication-only plan with no lifestyle/behavioural support or follow-up
- Idealised unrealistic targets; no comorbidity treatment
- No continuity / acknowledgement of relapse
Obesity — SCA Consultation Scorecard
NICE CG189 · Non-stigmatising · Comorbidity screen · Tiered pathway · GLP-1/bariatric eligibility
0/ 33 pts
Global Skills
Structure, language, responsiveness
0/7
Tasks
Clinical reasoning, diagnosis, management
0/15
Relating to Others
Communication, rapport, shared decisions
0/11
RAG Self-Assessment
🔴 Red
Stigmatising; "eat less move more"; no comorbidity/OSA screen; GLP-1 handled poorly; no goals; mood ignored; no follow-up
🟠 Amber
Respectful; partial comorbidity screen; tier/medication discussed vaguely; goals set; mood/OSA partly addressed; ICE partial
🟢 Green
Permission + reframe; full comorbidity + OSA + mood screen; secondary causes considered; tiered pathway + honest GLP-1/bariatric eligibility; realistic agreed goals; continuity; ICE all three
Complete the checklist to see your score and feedback
"I've come about those weight-loss injections everyone's talking about. I've tried every diet going and nothing sticks — honestly, I'm sick of being told to just eat less and move more. Can I get the jab?"
Who you are
Daniel Price, 44, delivery driver. BMI around 38, big waist. You've lost and regained weight on countless diets and feel like a failure; previous GP appointments left you feeling judged ("eat less, move more"). You snore loudly, wake up unrefreshed and feel sleepy in the afternoons. Your blood pressure was "a bit high" last time. Your dad had type 2 diabetes and a heart attack at 55. You sit in a van all day, eat on the go (garage food, energy drinks), and your mood's been low. You've seen the weight-loss injections online and want to try them — you're hoping that's the answer.
Hidden concerns (reveal if explored)
Feeling judged (main): you're braced to be lectured. If the doctor is respectful and treats it as a medical issue, you relax and open up.
Low mood: you've been down; eating is partly comfort. You'll admit this if asked kindly.
Sleep/snoring: you'll mention it if asked; you didn't realise it could be important.
Fear it's hopeless: deep down you fear nothing will work; honest hope helps.
Clinical details if asked
- Long history of weight cycling; multiple diets; regain each time
- Snores heavily, unrefreshing sleep, daytime sleepiness (relevant — you drive for a living)
- BP "a bit high" before; strong family history (father T2DM + MI at 55)
- Sedentary job; eats on the go; sugary drinks; mood low; alcohol moderate
- No rapid recent gain; no steroid use; no cold intolerance or easy bruising
- No binge-eating "episodes" as such, but you eat to cope when stressed
Reactions at key moments
- On the respectful reframe: visibly relieved; "no one's put it like that before."
- On the injection eligibility: a bit deflated it's not instant, but accepts a clear pathway.
- On sleep apnoea: surprised but takes it seriously, especially re driving.
- On realistic goals: reassured that 5–10% is worthwhile and achievable.
- Challenge line: "So you're not just going to give me the jab? Is this another 'eat less, move more' speech?"
"Be honest with me, doc — is this just going to be another lecture about eating less, or are you actually going to help me get these injections?"
Resolution: Daniel engages if the GP: (1) raises weight with permission and respect, reframing obesity as a medical condition and repairing the sense of being judged; (2) assesses holistically and screens comorbidities (HbA1c, lipids, BP, OSA, cardiovascular risk) and mood, considering secondary causes; (3) is honest about the injections — effective but criteria-based, usually via a specialist service, adjuncts to lifestyle, with regain on stopping — and sets him on the tiered pathway; (4) agrees realistic 5–10% goals and treats his comorbidities now; (5) arranges OSA assessment and supports his mood, with continuity. He disengages if lectured, dismissed, or promised/refused the injections without a real plan.
Clinic Quick Reference
Obesity — Clinical Decision Framework
NICE CG189 · BMI/waist · Comorbidity · Tiered pathway
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🔍 1 — Assess
Classify: BMI (overweight 25–29.9; obesity I 30–34.9, II 35–39.9, III ≥40) + waist, ethnicity-adjusted (−2.5 for South Asian/Chinese). Screen comorbidity: HbA1c, lipids, BP, LFTs (NAFLD), OSA (Epworth), QRISK, mood. Exclude secondary: hypothyroid, Cushing's, PCOS, weight-promoting drugs.
💊 2 — Tiered management
Tier 1–2: lifestyle/behavioural + community programmes; agree 5–10% goal. Tier 3: specialist MDT, pharmacotherapy (orlistat; GLP-1/dual agonists by criteria, time-limited, adjunct to lifestyle). Tier 4: bariatric surgery (BMI ≥40, or ≥35 with comorbidity, after Tier 3; ethnicity/T2DM nuances). Treat comorbidities now; non-stigmatising care; long-term follow-up.
SCA Quick Reference
Obesity — Consultation Playbook
Permission & respect · screen complications · honest tools · realistic goals
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🎯 The three pivots that pass this case
1 · The relationship
Raise weight with permission; reframe obesity as a chronic medical condition, not willpower. No stigma.
2 · Screen the complications
HbA1c, lipids, BP, NAFLD, OSA, cardiovascular risk, mood, secondary causes — obesity rarely travels alone.
3 · Honest tools & goals
Tiered pathway; GLP-1/bariatric are criteria-based adjuncts; aim for a realistic, lasting 5–10%.
⛔ Don't lecture or stigmatise ("eat less, move more") · Don't promise or refuse GLP-1/surgery without the criteria/pathway · Don't miss OSA (especially in a driver), low mood or disordered eating · Don't defer treating comorbidities until weight loss · Set realistic goals and provide continuity