The prevalence of
obesity has reached epidemic dimension in industrialized countries and it is known that
obesity is associated with increased risk of cardiovascular morbidity and mortality. Commonly,
obesity is defined by the Body Mass Index (BMI). However, BMI fails to consider body fat distribution. The relationship between the risk of metabolic-
cardiovascular diseases and body fat distribution indices such as the waist-to-hip ratio (WHR) and the waist circumference, rather than measures of the degree of body fatness as expressed by BMI, has long been recognized. Recently, clinical and epidemiological research has found waist circumference to be the best anthropometric
indicator of both total body fat and intra-abdominal fat mass. Android or
visceral obesity is associated with
metabolic syndrome and increased cardiovascular morbidity and mortality through a variety of molecular mechanisms possibly linking the
metabolic syndrome to
hemostatic and vascular abnormalities.
Obesity guidelines suggest the need for
weight reduction using behavioural change to reduce caloric intake and increasing physical activity. A realistic goal for
weight reduction is to reduce
body weight by 5% to 10% over a period of 6 to 12 months. Combined intervention of a low calories diet, increased physical activity, and behaviour
therapy provides better outcomes for long-term
weight reduction and weight maintenance than programs that use only one or two of these modalities. The drugs used to promote
weight loss have been
anorexic drugs or
appetite suppressants. All classes of
anorexic drugs affect
neurotransmitters in the brain. The new agent
sibutramine has
norepinephrine and
serotonin effects. Another new agent,
orlistat, has a different mechanism of action, the reduction of fat absorption.
Weight loss drugs approved by the FDA for long-term use may be useful as an adjunct to diet, physical activity and behaviour
therapy for patients with a BMI of > or =30 with no concomitant
obesity-related risk factors or diseases, and for patients with a BMI of > or =27 with concomitant
obesity-related risk factors or diseases.