Introduction to Obesity

Obesity is a major component of the metabolic syndrome.

Being overweight or obese significantly increases the risk of morbidity and mortality from Type 2 diabetes and its co-morbidities.

Successful weight reduction has a positive impact on morbidity and mortality outcomes.

Constitutional obesity is a result largely of diet and lifestyle.

Measurements for evaluation

  1. Body mass index (BMI): calculation for BMI = weight in kg divided by height in m², overall obesity expressed as kg/m²
  2. Waist circumference: determination of central fat distribution

Classification of BMI

  1. Underweight: <18.5kg/m²
  2. Normal weight: 18.5-24.9kg/m²
  3. Overweight: 25-29.9 kg/m²
  4. Obesity (Class 1): 30-34.9kg/m²
  5. Obesity (Class 2): 35-39.9 kg/m²
  6. Extreme obesity (Class 3): > 40 kg/m²

The pattern of distribution of fat in the body  (whether mostly peripheral or central) is assessed by the use of the waist/hip ratio (WHR).

Waist/Hip ratio-Waist circumference (in cm) divided by Hip circumference (in cm).

Waist circumference: measured midway between the lower rib margin and the iliac crests.

Hip circumference: the largest circumference of the hip.

Waist circumference better depicts central or upper body obesity than waist/hip ratio.

Upper limits: 102 cm and 88 cm in men and women, respectively.



  • Always bear in mind the possibility of an underlying cause: although these may not be common, specific therapy may be available.
  • Clinical presentation may therefore require specific investigations to exclude conditions such as hypothyroidism, hypercortisolism, male hypogonadism, insulinoma and CNS diseases that affect hypothalamic function

Complications of Obesity

  1. Cardiovascular: Coronary artery disease, Stroke, Congestive heart failure
  2. Pulmonary: Obstructive sleep apnoea, ‘Obesity hypoventilation syndrome’ diabetes mellitus
  3. Cancers:
  4. Endocrine: Insulin resistance and type 2
  5. Hepatobiliary: Gall stones
  6. Reproductive: Male hypogonadism; Menstrual abnormalities; Infertility
  7. In males, higher mortality from cancer of the colon, rectum and prostate
  8. In females, higher mortality from cancer of the gall bladder, bile ducts, breasts, endometrium, cervix and ovaries
  9. Bone, joint and cutaneous disease: Osteoarthritis, Gout Acanthosis nigricans
  10. Increased risk of fungal and yeast infections Venous stasis

Obesity Treatment objectives

  1. To educate patient and caregivers
  2. Achieve an ideal body weight
  3. Prevent complications


  1. Assess dietary intake, level of physical activity, BMI (total body fat) and waist circumference (abdominal fat) on presentation and at regular monitoring
  2. Assess efficacy of weight loss measures
  3. Integrate weight control measures into the overall management of diabetes mellitus and co-morbidities if BMI is >25, and Waist circumference is more 02 cm and 88 cm in men and women respectively
  4. Educate patients and other family members
  5. Set realistic goals
  6. Use a multi-disciplinary approach to weight control
  7. Dietary changes and increased level of physical activity are the most economical means to loose weight.
  8. Maintain records of goals, instructions and weight progress charts
  9. Surgical intervention may be required in extreme cases

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