management of obesity

Last reviewed 07/2023

Obesity is graded according to the Body Mass Index (BMI):

  • Healthy weight 18.5-24.9

  • Overweight 25-29.9

  • Obesity I 30-34.9

  • Obesity II 35-39.9

  • Obesity III 40 or more

Assessment of the health risks associated with overweight and obesity in adults should be based on BMI and waist circumference as follows (1):

BMI classificationLow Waist Circumference High Waist CircumferenceVery High Waist Circumference
Overweightno increased riskincreased riskhigh risk
Obesity I increased riskhigh riskvery high risk
  • for men, waist circumference of less than 94 cm is low, 94-102 cm is high and more than102 cm is very high
  • for women, waist circumference of less than 80 cm is low, 80-88 cm is high and more than 88 cm is very high.

The approach to management of obesity depends on the severity of obesity, the waist circumference, and any accompanying risk factors for complications:

  • Overweight patients
    • if no comorbidities present
      • low waist circumference - general advice on healthy weight and lifestyle
      • high waist circumference - diet and physical activity
      • very high waist circumference - diet and physical activity
    • if comorbidities present
      • diet and physical activity; consider drugs
  • Obesity I patients
    • if no comorbidities present
      • low waist circumference - diet and physical activity
      • high waist circumference - diet and physical activity
      • very high waist circumference - diet and physical activity
    • if comorbidities present
      • diet and physical activity; consider drugs
  • Obesity II patients
    • if no comorbidities present
      • low waist circumference - diet and physical activity; consider drugs
      • high waist circumference - diet and physical activity; consider drugs
      • very high waist circumference - diet and physical activity; consider drugs
    • if comorbidities present
      • diet and physical activity; consider drugs; consider surgery
  • Obesity III patients - Diet and physical activity; consider drugs; consider surgery

Notes:

  • the level of intervention should be higher for patients with comorbidities (such as type 2 diabetes, hypertension, cardiovascular disease, osteoarthritis, dyslipidaemia and sleep apnoea). The approach should be adjusted as needed, depending on the patient's clinical need and potential to benefit from losing weight

Reference:

  1. NICE (November 2014). Obesity guidance