Synopsis
Assess adiposity and its health effects without stigma, identify treatable drivers and complications, and build a sustainable multicomponent plan around the person's priorities and circumstances.
- Ask permission to discuss weight, use the person's preferred language and offer a private, accessible weighing environment with suitable calibrated equipment.
- BMI is a screening measure, not a direct measure of individual health, muscle, fat distribution, disability, ethnicity, pregnancy or lived experience.
- For adults with BMI below 35, waist-to-height ratio can add central-adiposity information; a waist less than half height is a simple population message.
- NICE advises lower BMI thresholds, usually by 2.5 kg/m², when assessing intervention eligibility for several ethnic groups who develop cardiometabolic risk at lower BMI.
- Assess consequences systematically: type 2 diabetes, blood pressure, lipids, cardiovascular disease, sleep apnoea, fatty-liver risk, osteoarthritis, reproductive health and mental wellbeing.
- Look for medicine-related weight gain, sleep disruption, food insecurity, pain, shift work, menopause, neurodivergence, disability and disordered eating before prescribing a generic plan.
- Routine endocrine screening beyond clinically indicated thyroid or cortisol assessment has low yield; targeted clues should drive secondary-cause testing.
- Behavioural treatment works best as an individualised package covering dietary quality and energy balance, activity, sleep, self-monitoring, problem-solving and social context.
- Set goals beyond kilograms, such as walking tolerance, glycaemia, blood pressure, sleep, pain, fertility planning and quality of life.
- Expect plateaux and relapse because weight regulation is biological and environmental; review the plan without blame and escalate to medicines or surgery when indicated.
Key red flags
Loud snoring, witnessed apnoeas, morning headache, unrefreshing sleep and daytime somnolence suggest obstructive sleep apnoea; awake hypoxaemia, hypercapnia or somnolence can indicate obesity hypoventilation.
Investigation priorities
Provide a reproducible baseline for population risk and treatment eligibility.
Management branches
Weight or central adiposity may be contributing to current health concerns.
- Ask permission, agree neutral language, provide privacy and accessible equipment, and establish what the person hopes will improve rather than imposing a target.
- Measure BMI and central adiposity where useful, then assess medical complications, medicines, sleep, mental health, eating pattern, mobility and socioeconomic constraints.
- Share risk in plain language, agree whether the focus is prevention, symptom relief or disease treatment, and document options including no immediate weight-loss intervention.
Severe comorbidity, safeguarding, disordered eating or complex disability limits routine management.
- Treat urgent respiratory, cardiovascular, glycaemic or psychiatric risk first and make reasonable adjustments so diagnostic care is not withheld because of size.
- Coordinate obesity medicine, dietetics, psychology, physiotherapy, respiratory, hepatology, diabetes or reproductive teams according to the complications actually present.
- Agree one accountable follow-up plan, including medicine review and crisis contacts, so multiple referrals do not leave the person without active care.