CHAPTER ONEINTRODUCTIONObesity is defined as abnormal or excessive fat accumulation with a Body Mass Index (BMI) of 30 kg /m2 or more that represents a risk to health (Han and Bchir, 2013).Obesity is undoubtedly one of the biggest medical problems of the 21st century. Regrettably, the problem affects children and adolescents. 10% of world’s school-aged children have an excess body weight and a quarter of these children are obese (see figure 1.1). Overweight and obesity are global public health problems because of their effect on individuals, families and communities (Alphonsus et al., 2014).The prevalence of overweight and obesity among Polish adolescents is about 14% (Karolina and Dominik, 2013). The socio-demographic determinants of obesity among adults in the Nigerian population were female gender, marriage, low physical activity level, positive family history, urban area of residence and age ≥ 40 year (Ekpenyong and Akpan, 2013). An excess body weight can be the consequence of genetic factors, endocrine disorders or certain drugs. However, ‘simple obesity’ is the most common, a consequence of providing too much energy from food products in comparison to energy expenditure (caloric excess). Prevalence of overweight and obesity is increasing in different populations, and is becoming a huge problem among occupational/professional groups that are perceived as preponderantly sedentary. An attendant acquisition or imposition of a lowered physical activity level and other lifestyle with such occupations may contribute to the development of obesity and overweight (Aryee et al., 2006).
1.1 Background of studyObesity is a public health problem that has raised concern worldwide. According to the World Health Organization (WHO), there will be about 2.3 billion overweight people aged 15 years and above, and over 700 million obese people worldwide in 2015 (WHO, 2009) but In 2016, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 650 million were obese. 39% of adults aged 18 years and over were overweight in 2016, and 13% were obese. Most of the world’s populations live in countries where overweight and obesity kills more people than underweight. 41 million children under the age of 5 were overweight or obese in 2016. Over 340 million children and adolescents aged 5-19 were overweight or obese in 2016. Obesity is preventable. Worldwide obesity has nearly tripled since 1975 (WHO, 2019).