Overweight and Obesity

Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.

Body Mass Index (BMI)[1] is one of the methods for measuring overweight and obesity.  It is calculated by dividing the body weight (in kg) by the square of height (in m): kg/m².  For assessing obesity in adult populations, according to the World Health Organization Asian Standard, BMI 23.0 - below 25.0 kg/m² is classified as overweight and BMI 25.0 kg/m² or above is classified as obesity.

Weight control should be achieved through good diet and appropriate exercise.  People should consult healthcare professionals before using any medication for weight control.

Medical Treatment

There are two medicines generally used for the treatment of obesity:

1.          Sibutramine

Sibutramine is an appetite suppressant used as adjunctive therapy within a weight management programme for obese patients.  Its side effects include increased blood pressure and heart rate, psychosis and possibly convulsion.  People with heart problems should not take it.

According to Pharmacy and Poisons Ordinance, Chapter 138, Laws of Hong Kong, a product containing sibutramine must be registered before it can be sold in Hong Kong.  It can be sold only on a doctor's prescription and dispensed under the supervision of a pharmacist.

2.          Orlistat

Orlistat inhibits gastrointestinal lipases and thus the absorption of fat.  It is used for the treatment of obese patients in conjunction with a mildly hypocaloric diet.  Side effects of orlistat include fatty or oily stool, increased defecation, flatulence and abdominal discomfort.

According to Pharmacy and Poisons Ordinance, Chapter 138, Laws of Hong Kong, a product containing orlistat must be registered before it can be sold in Hong Kong.  It can be sold only on a doctor's prescription and dispensed under the supervision of a pharmacist, except when contained in a pharmaceutical product of which the recommended dose is a quantity of the product that contains not more than 60 mg of orlistat taken 3 times a day, it should be dispensed under the supervision of a pharmacist.

From time to time, the Department of Health receives reports of persons feeling unwell after consuming slimming products with undeclared western drug ingredients that are purchased while traveling abroad.  In addition, some slimming products offered for sale on the internet were also found to contain undeclared western drug ingredients. 

Products which have not been registered according to the Pharmacy and Poisons Ordinance are potentially harmful as their safety, efficacy and quality could not be ascertained.  Therefore, people should not buy products of unknown composition or unknown source.  Persons who have overweight problem should consult medical professionals and not to use any unevaluated product.