Obesity

Obesity is a condition in which the natural energy reserve of humans or other mammals, which is stored in fat tissue, is expanded far beyond usual levels to the point where it impairs health. Obesity in wild animals is relatively rare, but it is common in domestic animals like pigs and household pets who may be overfed and underexercised. In humans it is considered a major challenge to health.

Therapy

The mainstay of treatment for obesity is an energy-limited diet and increased exercise. Although adherence to this regimen can cure obesity, many patients are unable to make the required sacrifices. In fact there are no studies showing that an energy restricted diet can lead to long term weight loss. It appears that the homeostatic mechanisms regulating body weight are very robust, thus impeding weight loss when attempted using calorie restriction.

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In a clinical practice guideline by the American College of Physicians{{mn|Snow|9}}, the following five recommendations are made:

Related Topics:
Clinical practice guideline - American College of Physicians

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• People with a BMI of over 30 should be counseled on diet, exercise and other relevant behavioral interventions, and set a realistic goal for weight loss.
• If these goals are not achieved, pharmacotherapy can be offered. The patient needs to be informed of the possibility of side-effects and the unavailability of long-term safety and efficacy data.
• Drug therapy may consist of sibutramine, orlistat, phentermine, diethylpropion, fluoxetine, and bupropion. Evidence is not sufficient to recommend sertraline, topiramate, or zonisamide.
• In patients with BMI > 40 who fail to achieve their weight loss goals (with or without medication) and who develop obesity-related complications, referral for bariatric surgery may be indicated. The patient needs to be aware of the potential complications.
• Those requiring bariatric surgery should be referred to high-volume referral centers, as the evidence suggests that surgeons who perform these procedures frequently have fewer complications.

Much research focuses on new drugs to combat obesity, which is seen as the biggest health problem facing developed countries. Some nutritionists feel that these research funds would be better devoted to advice on good nutrition, healthy eating, and promoting a more active lifestyle.

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Medication most commonly prescribed for diet/exercise-resistant obesity is orlistat (Xenical®, which reduces intestinal fat absorption by inhibiting pancreatic lipase) and sibutramine (Reductil®, Meridia®, an anorectic). In the presence of diabetes mellitus, there is evidence that the anti-diabetic drug metformin (Glucophage®) can assist in weight loss — rather than sulfonylurea derivatives and insulin, which often lead to further weight gain. The thiazolidinediones (rosiglitazone or pioglitazone) can cause slight weight gain, but decrease the "pathologic" form of abdominal fat, and are therefore often used in obese diabetics.

Related Topics:
Orlistat - Pancreatic - Lipase - Sibutramine - Anorectic - Diabetes mellitus - Anti-diabetic drug - Metformin - Weight loss - Sulfonylurea - Insulin - Thiazolidinedione - Rosiglitazone - Pioglitazone

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Increasingly, bariatric surgery is being used to limit stomach capacity (and thus food intake); this can happen laparoscopically. Ileal bypass reduces the length of the intestine and hence absorbing surface, but has more complications.

Related Topics:
Bariatric surgery - Laparoscopically - Ileal bypass

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