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
- Body mass index (BMI): calculation for BMI = weight in kg divided by height in m², overall obesity expressed as kg/m²
- Waist circumference: determination of central fat distribution
Classification of BMI
- Underweight: <18.5kg/m²
- Normal weight: 18.5-24.9kg/m²
- Overweight: 25-29.9 kg/m²
- Obesity (Class 1): 30-34.9kg/m²
- Obesity (Class 2): 35-39.9 kg/m²
- 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.
Investigations
Non-specific
- 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
- Cardiovascular: Coronary artery disease, Stroke, Congestive heart failure
- Pulmonary: Obstructive sleep apnoea, ‘Obesity hypoventilation syndrome’ diabetes mellitus
- Cancers:
- Endocrine: Insulin resistance and type 2
- Hepatobiliary: Gall stones
- Reproductive: Male hypogonadism; Menstrual abnormalities; Infertility
- In males, higher mortality from cancer of the colon, rectum and prostate
- In females, higher mortality from cancer of the gall bladder, bile ducts, breasts, endometrium, cervix and ovaries
- Bone, joint and cutaneous disease: Osteoarthritis, Gout Acanthosis nigricans
- Increased risk of fungal and yeast infections Venous stasis
Obesity Treatment objectives
- To educate patient and caregivers
- Achieve an ideal body weight
- Prevent complications
Management
- Assess dietary intake, level of physical activity, BMI (total body fat) and waist circumference (abdominal fat) on presentation and at regular monitoring
- Assess efficacy of weight loss measures
- 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
- Educate patients and other family members
- Set realistic goals
- Use a multi-disciplinary approach to weight control
- Dietary changes and increased level of physical activity are the most economical means to loose weight.
- Maintain records of goals, instructions and weight progress charts
- Surgical intervention may be required in extreme cases