A STUDY OF THE MOLECULAR ASPECTS OF OBESITY

Abstract

Obesity, the most common nutritional problem in many socities is defined as an excess of body fat that frequently results in a significant impairment of health (Jezek et al., 1994). It is expressed in terms of body mass index (BMI) which is calculated by dividing body weight in kilograms by height in meters squared. A person with BMI of 30 or greater is considered obese while a BMI between 25-29.9 is considered overweight (Kuczmarski et al., 1994). Obesity is a known risk factor for chronic diseases including: type 2 Diabetes Mellitus, hyperlipidaemia, heart diseases, hypertension and cerebrovascular stroke (Anderson et al., 1995).

Obesity is caused by sustained imbalance of food intake and energy expenditure. Evidence suggests that the development of obesity is a complex interaction between hormonal, genetic, psychological, socio­ economic and cultural factors (Herskind et al., 1996). The hormone leptin,discovered a few years ago, is a protein secreted by adipocytes and forms a signal linkage between the central nervous system and the beta 3-adrenergic receptors in adipose tissue. The interaction between epinephrine and leptin may operate during metabolic and psychological stress to regulate energy expenditure and food intake (Carulli et al., 1999).

Much attention has been focused on the identification of molecular pathways that contribute to the development of obesity (Comuzzie and Allison