1.      Background to the Study

Obesity is the result of long-term energy imbalances in which daily energy intake exceeds daily energy expenditure. Energy balance is modulated by a myriad of factors, including metabolic rate, appetite, diet, and physical activity. In some instances, endocrine problems, genetic syndromes, and medications can be associated with excessive weight gain (Ogden, Flegal, Carroll & Johnson, 2002). Over 2.8 million people die annually due to overweight or obesity. A global estimate of 2.3% (35.8 million) DALYs (Disability Adjusted Life Year) is as a result of being overweight and obese (WHO, 2015).

 In Nigeria, the prevalence of overweight individuals ranged from 20.3%–35.1%, while the prevalence of obesity ranged from 8.1%–22.2% (Chukwuonye,Chuku, John,Ohagwu,Imoh, Isa et al 2013). According to WHO (2014), it was projected that chronic diseases account for 24% of all deaths in Nigeria with cardiovascular disease accounting for 7% of this. Globally, the prevalence of overweight and obesity among children and adolescents has significantly increased over the last three decades particularly in Africa, Eastern Mediterranean Region (EMR) and Asia (Gupta, Goel, Shah & Misra, 2012). It has been recorded in Sagamu, Ogun State (south western Nigeria) that there is a prevalence of overweight of 8.1% in males and 8.1% in females. It further showed a low prevalence of obesity of 2.7% in males and 1.9% in females (Akinpelu, Oyewole & Oritogun, 2008).

World Health Organization defined overweight and obesity as abnormal or excessive accumulation of fat that may impair health (WHO, 2014). The pandemic of obesity and overweight has engulfed children and adolescents. It is estimated that 200 million school-aged children worldwide are overweight, of which 40-50 million are obese (WHO, 2014).

Today it is estimated that over 250 million people in low and middle income countries suffer from obesity, but globally more than one billion are overweight and 300 million are obese (Sabageh & Ojofeitimi, 2013). Once considered a high-income country problem, overweight and obesity are now on the rise in low and middle income countries particularly in urban settings (WHO, 2014).

Overweight and obesity have been recognized as one of the public health concern of the 21st century by World Health Organization (WHO, 2015). In the last few decades, the cause of death especially in the developing country like Nigeria has gradually been shifting from the infectious diseases to Non Communicable Diseases (NCDs) that were strongly attributed to overweight and obesity (Hallström,  Labayen, Ruiz, Patterson, Vereecken & Breidenassel, 2013).

Overweight and obesity are nutritional disorders emanating from calorie imbalances. These disorders develop when calorie consumption surpasses calorie expenditure, and the excess calorie gradually accumulates which later results into abnormal weight gain (Mokdad, Ford & Bowman, 2003).In Sub- Saharan Africa, there is an evidence of transition to obesity in adolescents despite historically known food shortages (Muthuri, Francis, Wachira, LeBlanc, Sampson, Onywera et al., 2014). These obese adolescents are likely to stay obese into adulthood and are more likely to develop non-communicable diseases (WHO, 2014).

Obesity is a major risk factor for non-communicable diseases such as cardiovascular diseases, diabetes, musculoskeletal disorders and cancers of breast, endometrial and colon.  Obesity has played‎ an ‎important‎ role ‎in ‎causing‎ “double‎ burden”‎ of‎ diseases‎ that‎ developing‎ countries are now facing (WHO, 2014).

Due to increased dietary changes, reduction in physical activity and increased obesity, it is estimated that the prevalence of diabetes will triple within the next 25 years (Swift, Glazebrook & Macdonald, 2006). Both obesity and type 2 diabetes are major public health problems throughout the world and are associated with significant potentially life-threatening co-morbidities and enormous economic costs. Obesity represents a serious threat to health through its association with conditions such as type 2 diabetes mellitus, coronary heart disease and certain types of cancers (Gordon, 2001). The increase in the prevalence of diabetes parallels that of obesity and both are emerging pandemics in the 21st century. Some experts call this dual epidemic “diabesity”. People who are obese more than 20% over their ideal body weight for their height, have insulin resistance and are at particularly high risk of developing type 2 diabetes and its related medical problems (Yaturu, 2011). 

Urbanization, modernization, sedentary lifestyle, consumption of oily and junk foods, and other lifestyle changes have contributed to overweight and obesity. Leaving aside the adult community, today, more and more adolescents are being diagnosed with diabetes, hypertension, and other comorbid conditions that are associated with obesity (Brahmbhatt & Oza, 2012). In adolescents, obesity is slowly emerging as a main public health issue in many developing countries. Adolescence is a pivotal period of life, where major physiological and psychological changes take place, which would transform into adult behaviour and health status. Adolescence is the period of crucial growth. During this phase physical changes including growth, the onset of menarche for the girls, and increase in fat and muscle mass takes place.  This contributes to obesity.

Leisure pursuits are suspected as major contributors to rising levels of obesity (WHO, 2004). The frequency of consumption of energy dense snacks and sugary beverages has increased considerably particularly among the adolescent students in urban areas and in private schools. Also physical inactivity which has been observed to increase among the adolescents due to the use of varieties of electronic devices that keep them busy during the day and awake  throughout the night (Mar Bibiloni, Pich, Córdova, Pons & Tur, 2012).

It has been established through several studies that overweight and obesity caused high morbidity and mortality among different age groups (Wang, Jahns, Tussing-Humphreys, Xie, Rockett, Liang et al., 2010). Adolescents who are overweight could experience conditions like depression, anxiety, low self-esteem and peer rejection. (Aounallah-Skhiri, El Ati, Traissac, Romdhane, Eymard-Duvernay, Delpeuch et al., 2012).

1.2       Statement of the Problem

The dietary transition recently going on in Africa is contributing greatly to high mortality and morbidity attributed to overweight and obesity (Smpokos, Linardakis, Sarri,Papadaki, Theodorou & Kafatos, 2013). It has exposed a lot of Africans to a new lifestyle, a lot of things are done which pose a threat to lives such as poor diet, lack of physical activities, spending too much time watching the television, intake of energy drinks and soda. Adolescents adopt this new lifestyle and engage in intake of junks which has been referred to as fast food, intake of energy drinks as much as they can get, intake of alcohol, sedentary lifestyles such as spending hours watching the television. These contribute a great deal to the amount of calories gained, and the accumulation of these overtime leads to weight gain that cannot be controlled due to the consistent intake of these foods (Mozaffarian, Hao, Rimm, Willett & Hu, 2011).

Studies have revealed sedentary behaviour, increased intake of junks and physical inactivity to be predisposing factors to obesity. Indicating presence of these factors may subsequently lead to high incidence rate of obesity. In a study carried out by Mustapha and Sanusi (2013) in Ondo state showed that about 5.76% adolescents were overweight while 1.13% were obese which may be regarded as low compared to other developed countries.

Obesity has become a major problem of adolescents and this has been associated with adulthood. Despite the high level of information and knowledge of obesity as evident in researches carried out by Marta, Magdalena, Aleksandra, Sylwia, Lukasz, Tomasz et al., (2014), there is still an increase in the prevalence of obesity among secondary school adolescents as a result of the research carried out by Jaja & Alex, 2016. This indicates that there are other factors which might be responsible for the increase in the prevalence of obesity especially social factors including knowledge, attitude, and behaviour related to diet, exercise, nutrition, and overall health in addition to age, race, and gender (Sarrafzadegan, Rabeje, Nouri, Mohammadifaed, Moatter, Roohafza et al., 2013).

 Literature have been showing incoherent data about the prevalence of obesity among adolescents. No literature has yet been released on the prevalence of obesity among adolescents in Ekiti and also the presence of the factors preceding obesity among adolescents has not been documented which this study intends to explore.