Overview
Obesity describes excess body fat and is classified according to body mass index (BMI):
- Healthy weight – BMI of 18.5–24.9 kg/m2
- Overweight – BMI of 25–29.9 kg/m2
- Obesity 1 – BMI of 30–34.9 kg/m2
- Obesity 2 – BMI of 35–39.9 kg/m2
- Obesity 3 – BMI of 40 kg/m2 or more
BMI is calculated using weight (kg) divided by height in metres squared (m2)
Management
Management is stepwise:
- Lifestyle changes and weight management programmes
- Drug treatment:
- Oral orlistat (pancreatic lipase inhibitor):
- Prescribed if:
- BMI ≥28 kg/m2 with associated risk factors (e.g. type 2 diabetes mellitus, hypertension, or dyslipidaemia) or
- BMI ≥30 kg/m2 or more
- Adverse effects:
- Bloating, faecal urgency, steatorrhoea
- Liraglutide subcutaneous injection – GLP-1 mimetic:
- Prescribed if:
- BMI ≥35 kg/m2 (or ≥32.5 kg/m2 in members of minority ethnic groups with an increased risk of complications at a lower BMI compared to the white population) and they have one of the following:
- Non-diabetic hyperglycaemia
- High risk of cardiovascular disease (e.g. dyslipidaemia and hypertension)
- BMI ≥35 kg/m2 (or ≥32.5 kg/m2 in members of minority ethnic groups with an increased risk of complications at a lower BMI compared to the white population) and they have one of the following:
- Prescribed if:
- Bariatric surgery:
- If BMI >50 kg/m2 and other interventions have not been effective
- May be considered in people with a BMI >35 kg/m2 with other significant diseases that could be improved with weight loss (e.g. type 2 diabetes, hypertension, or mobility issues).
