Obesity is a complex, multifactorial, chronic disease involving environmental (social and cultural),
genetic, physiologic, metabolic, behavioral, and psychological components. It has been increasing
at an alarming rate throughout the world over the past two decades to the extent that it is now a
pandemic, affecting millions of people globally, and it is the second leading cause of preventable
death in the United States. The World Health Organization (WHO) has estimated that more than
300 million people are obese worldwide [1].
Obesity is defined as a condition of excess body fat, and it is associated with a large number
of debilitating and life-threatening disorders, such as major
increases in associated cardiovascular,
metabolic, and other noncommunicable
diseases [2]. It also contributes to increased mortality rates
from all causes, including cardiovascular diseases (CVDs) and cancer.
The obesity prevalence rate increase is evident in Westernized countries, where obesity
has
been present for decades, but today it
is also particularly noticeable in less developed countries
that
previously had not experienced problems with overweight and obesity. For example, the prevalence
of obesity has increased by about 10 to 40% in the majority of European countries in the last
decade, and it currently affects nearly one third of the adult American population, as well as three
quarters of the adult population living in urban areas of Western Samoa in the Pacific [3].
Obesity in the developing world reflects the profound changes in society over the past 20 to
30 years that have created an environment that promotes a sedentary lifestyle and the consumption
of a high-fat, energy-dense diet, collectively known as the
nutrition transition