Obesity
This article is general health information for the selected condition. It is not a diagnosis and does not replace clinical judgement. If you have questions or need treatment advice, please consult a qualified healthcare professional.
What is obesity?
Obesity is excess body fat sufficient to impair health, usually defined by a body mass index of 30 or above, with lower thresholds appropriate for some ethnic groups. It is now understood as a chronic relapsing disease driven by biology, environment and genetics rather than a simple failure of willpower, and effective treatments have expanded considerably.
Causes
- Sustained energy intake exceeding expenditure
- Strong genetic influence on appetite regulation
- Obesogenic food environment
- Physical inactivity and sedentary work
- Poor sleep and shift work
- Medicines including some antipsychotics and steroids
- Endocrine causes such as hypothyroidism and Cushing syndrome
Symptoms
- Body mass index of 30 or above
- Increased waist circumference
- Breathlessness on exertion
- Joint pain, particularly knees and hips
- Snoring and daytime sleepiness
- Fatigue
- Skin changes in body folds
- Often no symptoms until complications appear
Risk factors
- Family history of obesity
- Socioeconomic deprivation
- Sedentary occupation
- Chronic sleep deprivation
- Certain psychiatric medicines
- Pregnancy and menopause
- Previous weight cycling
Diagnosis
- Body mass index calculation
- Waist circumference and waist to height ratio
- Assessment for complications including diabetes and sleep apnoea
- Blood pressure, lipids and HbA1c
- Liver function and fibrosis assessment
- Thyroid function to exclude a secondary cause
Treatment
- Structured dietary change with realistic sustained deficit
- Regular physical activity, valuable independent of weight loss
- Behavioural and psychological support
- GLP 1 receptor agonists such as semaglutide
- Dual agonists such as tirzepatide
- Bariatric surgery for severe obesity or with complications
- Treating contributing medicines and sleep disorders
Self care
- Set realistic goals, since 5 to 10 percent loss brings real health benefit
- Focus on sustainable changes rather than short term dieting
- Build regular physical activity, valuable even without weight change
- Prioritise sleep, since short sleep drives appetite
- Track intake honestly for a period to build awareness
- Seek structured support rather than going it alone
- Address emotional eating with appropriate help
When to see a doctor
Book an appointment if:
- Weight affecting mobility, breathing or joints
- Snoring with daytime sleepiness
- Difficulty losing weight despite genuine effort
- Symptoms of diabetes or high blood pressure
- To discuss medication or bariatric surgery options
- Rapid unexplained weight change in either direction
Some symptoms need emergency care rather than an appointment. See the warning signs listed above.
Prevention
- Build sustainable eating and activity habits early
- Limit sugary drinks and ultra processed foods
- Prioritise adequate sleep
- Address weight gain from medicines with your prescriber
- Support children with activity and food environment rather than restriction
Outlook
Obesity is a chronic relapsing condition, and weight regain after loss reflects biology rather than failure. Modest sustained loss produces substantial improvements in diabetes, blood pressure, sleep apnoea and liver health. GLP 1 based medicines and bariatric surgery now achieve results that were not previously possible, though ongoing support remains necessary.
Common questions
Is body mass index a reliable measure?
It is useful at population level but imperfect individually, since it cannot distinguish muscle from fat and does not show fat distribution. Waist circumference adds important information about metabolic risk.
Why is weight regain so common?
Weight loss triggers biological adaptations that increase appetite and reduce energy expenditure, defending the previous weight. This is physiology rather than failure, and it is why obesity is managed as a long term condition.
How much weight loss is worthwhile?
Losing 5 to 10 percent meaningfully improves blood pressure, glucose control, liver fat and sleep apnoea. Health benefits begin well before reaching any cosmetic or ideal weight target.
References
Important: Dard AI is not a medical device and does not diagnose, treat, or replace clinician judgement. This article is general information only. Always consult a qualified healthcare professional about diagnosis and treatment, and seek emergency care for severe or rapidly worsening symptoms.