Obesity

Not all obese people eat more than the average person, but all obviously eat more than they need!

Obesity is a leading preventable cause of death worldwide, with increasing prevalence in adults and children, and it is viewed as one of the most serious public health problems of the 21st century. Obesity is stigmatized in the modern western world, though it has been perceived as a symbol of wealth and fertility at other times in history, and still is in many parts of Africa.

WHO Classification:
Overweight - BMI 25 - 30.
Obese
Class I / moderate - BMI 30 - 35
Class II / severe - BMI 35 - 40
Class III/ very severe - BMI more than 40

Aetiology:

• Genetics
• Endocrine - hypothyroidism, Cushing's syndrome and growth hormone deficiency
• Obstructive sleep apnoea
  
• Life style - sedentary habit, increased calorie intake

Morbidity and Mortality associated with obesity:

• Psychological
• CVA
• Cardiovascular: Hypertension, IHD, PVD and heart failure
• Respiratory: OSA/OHS
• Gatroenterology: hiatus hernia, fatty liver, gall stones
• Endocrine: diabetes, hyperlipidaemia
• Musculoskeletal: back pain, osteoarthritis, varicose vein and recurrent cellulitis.

Treatment of Obesity:

It should be divided into initial weight loss phase and long term maintenance phase.
Initial weight loss phase:

Increasing energy expenditure:

• Unfortunately increased physical activity alone with no change in food intake is associated with only moderate weight reduction.
• Many patients simply compensate for increased activity by increasing their food intake.
• Commercial weight loss program are available.

Reducing energy intake:
Life Style changes:

• Food chart
• Dietician advices about reducing portion of food intake and change in energy density of food
• Psychological method such as distraction away from food

Pharmacological methods:

Sibutramine is a noradrenaline and serotonin reuptake inhibito that acts centrally to increase satiety while increasing energy expenditure. It is available as 10 mg or 15 mg dose.
It side effects include insomnia, agitation and constipation as well as slight increase in blood pressure.

Orlistat is a lipase inhibitor acting in the intestine to decrease the absorption of fat by approximately 30 %. Its side effects include flatulence, bloating or other gastrointestinal effects.

Sertraline and fluoxetine are not licensed for the management of obesity but they can be of particular benefit in patients with mild depression or with obsessive thoughts regarding food intake. For many patients these drugs can limit the sense of deprivation associated with dieting.

Non-pharmacological methods:

Although patients with simple obesity ( BMI between 30 - 40 ) can lose weight using many different techniques, those with morbid obesity has many limitations including poor mobility.

Patients with extreme morbid obesity ( BMI > 50 ) have great difficulty walking more than 2000 steps a day.

Three non-pharmacological methods are currently used:

Very low calorie diets - optifast

• Optifast three meals per day replacement take in fewer than 800 calories per dya yet do not feel hunger because they produce ketones. It is also used in Australia to reduce liver size prior to a laproscopic gastric band procedure.

Intragastric balloon is beneficial for in obese patients with lower BMI ( 30 - 35 ) who do not fit the criteria for a laproscopic gastric banding procedure.

Bariatric surgery - either restrictive or malabsorptive or both.

• Indications: BMI > 40 or BMI > 35 with complications such as DM, IHD, Hypertension or sleep apnoea.

Maintenance phase:

A new concept of weight maintenance is the idea of a trigger weight.

Patient try to maintain their weight by reducing energy intake and increasing their energy expenditure. Once they hit above the trigger weight, they come back for the initial successful methods of weight loss.