ABSTRACT
Obesity is a disorder of energy imbalance, wherein energy input exceeds output. Excess energy is stored in the form of triglycerides in the adipose tissue. Increased adipose cell size causes hypertrophic obesity and increased cell number causes hyperplastic obesity characteristic of a more severe condition. The key causes of obesity are the increased consumption of energy-rich but nutrient-poor diets (like saturated fats and sugars) and reduced physical activity. 65% of the U.S.A. population is overweight, defined as body mass index (BMI) greater than 25, and approximately 25% of the population is obese, defined as BMI 30 (1). The prevalence of obesity has increased dramatically over the last decade (2), a trend seen in many industrialized countries (3). According to the World Health Organization, there are more than one billion overweight adults in the world, of which at least 300 million are clinically obese. The health care burden of obesity is significant due to associated secondary chronic diseases such as type 2 diabetes, hypertension, stroke, cardiovascular diseases, respiratory disorders, gallbladder disease, osteoarthritis, and certain cancers (4). The increasing evidence that severe obesity has a genetic basis, resulting in the maintenance and defence of elevated weight (5) may explain why long-term weight loss is very difficult to achieve. This has strengthened the argument that severe obesity should be treated with pharmacological agents along with conventional diet and exercise regimes. To date, approved therapeutics have met with only moderate success and have had
side effects, leaving an unmet need for effective and safe pharmacotherapy that poses a challenge to the pharmaceutical industry.
