What is obesity?
Obesity is a chronic medical condition in which excess body fat affects overall health. It is defined using the Body Mass Index (BMI), where a BMI of 30 kg/m² or higher indicates obesity.
Obesity is not simply a result of overeating — it is a complex endocrine and metabolic condition influenced by genetics, hormones, environment, and lifestyle.
How obesity is classified
- Class I obesity: BMI 30–34.9
- Class II obesity: BMI 35–39.9
- Class III obesity (severe): BMI 40 or higher
Waist circumference and body composition may also be assessed to evaluate metabolic risk.
What’s the outlook for obesity?
Obesity increases the risk of several health conditions, including:
- Type 2 diabetes
- High blood pressure
- Heart disease
- Sleep apnoea
- Fatty liver disease
- Joint problems
- Certain cancers
The good news is that even modest weight loss - 5-10% of body weight - can significantly improve health outcomes.
What are the symptoms of obesity?
Symptoms vary but may include:
- Fatigue
- Breathlessness
- Joint pain
- Low mood or reduced confidence
- Sleep disturbances
- Snoring or sleep apnoea
Some individuals may have no obvious symptoms but still face increased metabolic risk.
How is obesity diagnosed?
Diagnosis typically includes:
- BMI measurement
- Waist circumference
- Blood tests (glucose, lipids, liver function, thyroid function)
- Blood pressure
- Assessment of lifestyle, sleep, and eating patterns
An endocrinologist may also evaluate for hormonal causes of weight gain.
What causes obesity?
Obesity is influenced by multiple factors, including:
- Genetics
- Hormonal imbalances (e.g., thyroid, cortisol, insulin resistance)
- Medications
- Sleep patterns
- Emotional or stress‑related eating
- Environment and lifestyle
It is a medical condition — not a personal failure.
How is obesity treated?
Treatment is personalised and may include:
- Nutritional guidance
- Physical activity plans
- Behavioural support
- Medications for weight management
- Treatment of underlying hormonal conditions
- Referral for bariatric surgery in selected cases
Modern weight‑management medications can be highly effective when used under specialist supervision.
Which doctor should I talk to?
Obesity is best managed by an endocrinologist with expertise in metabolic health, often working alongside dietitians, psychologists, and weight‑management specialists.
OBESITY