CHAPTER ONE
INTRODUCTION
1.1 Background to the study
The English word “obesity” derives, from the Latin word obesus meaning ‘fat’ or plump. The first English use of the word was made in 1651 in Noah Bigg’s medical book ‘metaeotechnia medicinae praxeos’ (Mckeigne, 1996). Clinical evidence of obesity can be dated as far back as Greece Roman times but little scientific progress was made towards understanding the condition until the 20th century (James, 2005). Also, the discovery that fat is stored in ‘cells’ the basic unit of biology, led to the idea that obesity could be caused by the presence of too many fat cells (hyperplasia) (WHO, 1990).
Obesity in children is a complex disorder. Childhood obesity predisposes them to insulin resistance and type 2 diabetes, hypertension, hyperlipidemia, liver and renal disease, and reproductive dysfunction. This condition also increases the risk of adult-onset obesity and cardiovascular disease.The body mass index (BMI) has not been consistently used or validated in children younger than 2 years, because weight varies in a continuous rather than a stepwise fashion, the use of these arbitrary criteria is problematic and may be misleading. Nevertheless, children and adolescents defined as overweight or obese according to published criteria are highly likely to maintain this ponderal status as adults. Metabolism, lifestyle, and eating habits, are believed to play a role in the development of obesity.
In Nigeria, like in most developing countries of Africa, the emphasis has been on under nutrition and food security rather than overweight, since obesity is viewed as a disease of affluence, but recent studies has proved otherwise (Power, Lake & Cole, 1999).
Obesity is negatively affecting adults. Recent studies have shown that there are approximately 550 million obese people with a BMI of 30.0 and over 2 billion overweight people with a BMI of 25 and over in the world. (American Obesity Association (AOA), 2005) Overall, about 3 million deaths are attributed to overweight/obesity world-wide. The World Health Organization (WHO) in their recent national survey for chronic, non- communicable disease risk factors, identified that between 8% and 10% of Nigerian people are obese (WHO, 2002).
Children and teenagers are becoming obese at an alarming rate (Whitaker, Wright, & Pepe 1999). The prevalence of childhood obesity in the world has risen dramatically in the past several decades with 25-30 percent of children being affected; it is not confined to the industrialized countries, as high rates are already evident in developing countries (Moran, 1999). All children gain weight as they grow older but extra pound more than what is needed to support their growth and development can lead to childhood obesity. Childhood obesity is a serious medical condition that affects children and adolescents. It occurs when a child is well above the normal weight for his or her age and height. Childhood obesity is particularly troubling and can be dangerous to ones health. The treatment of obesity in adults give disappointing results because, rebound weight gain within months is present in the vast majority of adults who loose weight, but behavioral interventions in children population may yield greater weight loss and better maintenance than in adults (Epstein, 1998). Moran(1999) have recommended that making steady changes in eating and physical activity habits overtime, will bring about weight loss, better feeling and overall health improvement.
1.2 Statement of the Problem
The prevalence of childhood obesity has highly increased in several traditional populations. This is not only of social concern, it is also of public health concern, (Garrow, 1991). Obesity is considered a disease and one of the key risk factors for many chronic non-communicable diseases, such as type 2 diabetes mellitus, high blood pressure, heart disease and some cancers. The most important long term consequence is their persistence into adulthood, with all the associated health risks (Anderson & Musaiger, 2006). The rapid increase in childhood obesity predicts the future health consequences.
The Centre for Disease Control and Prevention (2003), reported that social and psychological problems are the most significant consequences of obesity in children. Furthermore, obese children may have psychological problems because the extra weight often place kids on the path to health problems such as diabetes, high blood pressure and high cholesterol that were once confined to adults. Dietz (1999) reported that, obesity has so many complications. The glaring rise in childhood obesity forced the World Health Organisation (WHO) to include childhood obesity on the list of essential health problems worldwide, and proposed it as the most frequent cause of preventable deaths, after smoking (WHO, 1998).This rise is attributed to drastic changes in the lifestyle of the children.
The dietary habits of the average Nigerian child in the urban communities had shifted from natural traditional foods to high-calorie foods (fast food and confectionary) which are relatively cheap and heavily promoted, specifically for children. Exercise is no longer a regular part of daily activity. Some children never walked or cycled to school or play any kind of sport. Schools in the urban areas do not have enough open play ground for the children. This has promoted in door games such as video games for children in the schools in recent times. It is not unusual now for children to spend hours in front of a television or computer.
The National Institute for Clinical Excellence (2000) observed that 4 out of 10 boys and 6 out of 10 girls scarcely perform a minimum one hour daily physical activity recommended by the health education authority. The past generation was hard-working and produced hard-working children who maintained active life style and such did not have to deal with the issues and complications of childhood obesity. The growth of economy led children of affluent parents to have no interest in manual labour. This may have precipitated a society of children suffering from overweight and obesity. This is supported by several studies that observed that childhood obesity is increasing. The option available is a strategy to reduce and prevent it. It was in the light of this study emanated, to conduct an extensive study on the prevalence of childhood obesity among children residing in the rural and the urban communities of Enugu South Local Government Area of Enugu State, Nigeria. The study provided evidence on prevalence of obesity in the communities and possible means of reducing it.
1.3 Objectives of the Study
1.3.1 General objective
The
general objective of this study was to assess the prevalence of childhood
overweight and obesity; and influence of exercise in children aged (6-12 years)
living in rural and urban communities of Enugu South local Government Area,
Enugu State, Nigeria.
1.3.2 Specific objectives:
The specific objectives were to:
1. determine the prevalence of childhood overweight and obesity in school children in Enugu South Local Government Area using anthropometric measurements;
2 determine the effect of gender, location and income of the parents on overweight and obesity in children using questionnaire.
3. assess the food consumption pattern of a sub-sample of the subjects using weighed food intake;
4. assess the effect of physical exercise on a sub-sample of the subjects weight; and
5. assess the effect of lifestyle on the subjects’ weights.
1.4 Significance of Study
Childhood obesity is not just a matter of social concern, but is also a health concern that can lead to health problems. The result of having obesity at such a young age means that these children are more susceptible to diseases, the majority of which would be completely preventable if obesity was avoided or reversed. Parents need to be willing to work out ways to keep children free from this disease and this will begin by creating awareness on the existence of this killer disease among our children and its resultant consequences.
The risk of health problems starts when someone is very slightly overweight, and the likelihood of problems increases as the person becomes more overweight and obese. Many of these conditions cause long-term suffering for individuals and families. In addition, the costs for the health care system are extremely high. This study therefore aims at unraveling the existence of this disease among children living in both the urban and rural areas of Enugu State, within the age range of 6-12 years, by first, carrying out an anthropometric measurement of the sampled population and calculating their BMI with the figures gotten.
To reach this goal of ideal body weight, people can limit energy intake from total fats and shift fat consumption away from saturated fats to unsaturated fats; increase consumption of fruit and vegetables, as well as legumes, whole grains and nuts; and limit their intake of sugars. And to increase calories used, people can boost their levels of physical activity – to at least 30 minutes of regular, moderate-intensity activity everyday.
The study could identify the major causes of obesity in children and ways of addressing the problem. The study will expose parents to the reality of obesity in children, its prevailing threats. and how to control and monitor the weight of a younger person. The result of this study will be of immense relevance to both adults, the children and virtually everybody who desire to live a healthy happy life. Parents will learn ideal home made delicacies that will positively affect the lives of these younger generations.
This study will reassure hope to those who are already victims of obesity. The Scientists, the Nutritionists, the Dietitians and all other concerned individuals including the various government units, will updatetheir knowledge on the prevalence of childhood obesity in the localities and the most appropriate means of fighting it. It is also assumed that this study will be useful in obtaining and disseminating information that will educate everybody especially parents on how to prevent the early onset of obesity among children.
CHAPTER TWO
LITERATURE REVIEW
Outline of the Review
2.1 Definition of Obesity
2.2 Historical Trends
2.3 Mechanism of Obesity
2.4 Classification of Obesity
2.5 Types of Obesity
2.5.1 Juvenile onset Obesity
2.5.2 Adult onset Obesity
2.5.3 Upper body (android) Obesity
2.5.4 Lower body (gynoid) Obesity
2.6 Epidemiology of Obesity
2.7 Cultural and Social Significance
2.8 Obesity Among Children
2.9 Prevalence of Childhood Obesity in Developed Countries
2.10 Prevalence of Childhood Obesity in Developing Countries
2.11 Prevalence by Region
2.12 Causes of Childhood Obesity
2.13 Problems of Childhood Obesity
2.14 Summary of Literature review
2.1 Definition of Obesity
An American Heritage Dictionary defines Obesity as condition of increased body weight and is caused by an excessive accumulation of fat. Obesity has been termed the new “epidemic” in both children and adults. In 1998, the World Health Organization (WHO) designated obesity as a global epidemic (Anrig, 2003). The combination of increasing high fat foods in our diets and low physical activity. It is very easy to become over weight/obesed in today’s society. The cost of obesity in Canada for example has tripled. Studies have shown that obesity has killed people more than AIDS. However, insurance companies rarely cover any cost that are associated with treatment for obesity (Kempster, 2004). Obesity, an accumulation of excess fat in the adipose tissue, is currently an escalating epidemic that affects many countries in the world including United States of America (Mccauley, 2002). This condition is responsible for 300,000 deaths annually. And it is attributed to changes in lifestyle, dietary habits, physical activity, social and economic evolvement associated with the occurrence of obesity (Allison & Engel, 1996). Some other major reasons for childhood obesity according to the American Obesity Association 2005 are:
1. poor eating habits, especially when children are exposed to other children who promote sedentary behaviours.
2. socio-economic stress and genetics
When a child has genetically obese background, the chances of becoming obese are greatly increased.
2.2 Historical Trends
Obesity has been recognized as a medical disorder since the time of Hippocrates when it was stated that “Corpulence is not only a disease itself, but the harbinger of others (Haslam and James 2005). For most of human history, mankind struggled with food security with the onset of the industrial revolution, it was realized that the military and economic might of nations were dependent on both the body size and strength of its soldiers and workers. Height and weight thus both increased through the 19th century in the developed world. During the 20th century, as populations reached their genetic potential for height, weight began increasing much more than height, resulting in obesity (Caballero, 2007). In the 1950’s increasing wealth in the developed world decreased child mortality and increased body weight but as body weight increased, heart and kidney disease became more common (Caballero, 2007). During this same period, insurance companies realized the connection between weight and life expectancy and increased premiums of the obese (Haslam and James, 2005).
2.3 Mechanism of Obesity
During growth, fat cells increase in number and when energy intake exceeds expenditure fat cells increase in size. When fat cells have reached their maximum size and energy intake continues to exceed energy expenditure, fat cells increase in number. With fat loss, the size of the cells shrinks, but not the number. When fat loss occurs, none of the cells decrease in number instead they only decrease in size. (Whitney and Rolfes, 2002). (There are few fatty acids that occur in food or in our body and are often incorporated in the form of triglycerides which are found in highly fatty foods. Triglycerides are composed of three fatty acids attached to a glycerol molecule, to make triglycerides a series of condensation, reaction takes place with fatty acids combining with a hydrogen atom to form a fatty acid, releasing a molecule of water. Triglycerides have recently become popular since they extend the shelf life of many food products by protecting them against oxidation.
A disadvantage to triglycerides is that they make poly-saturated fat more saturated. Therefore, any health advantage of using poly-saturated fat is lost during the process of hydrogenation and textures of food are also altered. (Whitney and Rolfes, 2002). Research has revealed that obesity is associated with increased levels of a hormone called leptin (Moran and Philip 2003). Leptin is secreted from adipose (fat) tissue and is involved in the regulation of food intake, energy expenditure and energy balance in humans (Moran and Philip 2003). In children today, obesity is the major and most common metabolic and nutritional disease, whereas thirty (30) years ago, it was rarely seen in children. In the past 20 years, there has been an exponential increase in the incidence of obesity among children. A study done by Tremblay and Williams (2000). showed that there were a 17% increase in obesity rates among boys and a 15% increase among girls, since 1981 to 1996. This alarming increase in childhood obesity has been occurring in all westernized countries and specifically in Canada. While childhood obesity rates were similar to other countries like Scottand, England and Spain in early 1980’s. By the 1990’s, Canadian rates rose by leaps and bounds (Ball and McCarger, 2003).
2.4 Classification of Obesity
Obesity in absolute terms is an increase of body adipose tissue (fat tissue) mass. In a practical setting, it is difficult to determine this directly. Therefore obesity is best and typically assessed by BMI (Body Mass Index) and in terms of its distribution via, the waist circumference (Sweeting, 2007). In addition, the presence of obesity needs to be evaluated in the contex of other risk factors such as medical conditions that could influence the risk of complications (Maynard et al., 2001).
Body Mass Index (BMI), developed by Belgian century, is a widely accepted scale to measure obesity (Parson, Power, Logan and Summerbell, 1999). BMI is an accurate reflection of body fat percentage in the majority of the adult population, but is less accurate in situations that affect body composition such as in body builders and pregnancy (Department of Health).
BMI is calculated by dividing the subjects weight by the square of his/her height, typically expressed either in metric or US “customary” units.
Metric: BMI = kg/m2
Where kg is the subject’s weight in kilograms and M is the subject’s height in meters.
The most commonly definitions, established by the WHO in 1997 and published in 2000 provide the following values (WHO, 2000).
A BMI less than 18.5 is underweight
A BMI of 18.5 – 24.9 is normal weight
A BMI of 25.0 – 29.9 is overweight
A BMI of 30.0 – 34.9 is class I obesity
A BMI of 35.0 – 39.9 is class II obesity
A BMI of > 40.0 is class III obesity.
Some modifications to the WHO (2000) definitions have been made by particular bodies (National Institute for Health and Clinical Excellence). A BMI of 35.0 or higher in the presence of at least one other significant commodity is also classified by some bodies as morbid obesity. To interpret BMI, physicians take into account race, ethnicity, lean mass, age, sex and other similar factors. Although there is no dispute to accept BMI to measure obesity, but it is not accurate in judging body fat of a very muscular person, It is also not correct in measuring waist circumference as it does not take into account different rations of adipose to lean tissues.
BMI also cannot differentiate between separate types of adiposity, which on many occasions relates to cardiovascular danger. There is an alternative way, scientists and physicians believe that men with over 25 percent body fat and women with over 30 percent body are obsessed (Willet, 1995). There is however difficulty in precisely measuring excessive fat of a person’s body. Experts suggest that the underwater weight of a person could be closer to an accurate answer. But underwater measurement is not generally possible for all the people. It can be conducted in laboratories only.
Another alternative is the skin-fold test which is dependable and can be easily conducted (used to determine the thickness of sub factor fat layer). The bioelectrical impedance analysis (BIA) is also acceptable to doctors because of its easy conductibility in medical clinics. Other types of measurement are computed tomography (CT Scan) and magnetic resonance imaging (MRI) and dual energy x-ray absorphometry (DXA). Measurement of risk factors and diseases associated with overweight can be judged by clinical analysis.
For Asian, overweight is a BMI between 23 and 29.9 kg/m2 and obesity a BMI > 30 kg/m2. The surgical literature breaks down “class III” obesity into further categories.
A BMI > 40 is severe obesity
A BMI > 40.0 – 49.0 is morbid obesity
A BMI of 50 is super obese
Body mass index (BMI) calculation and classification in children
The body mass index of children is calculated using the formula,
Weight (kg)
Height(m2)
The classification is done using WHO (2007) growth reference (5 – 19years),
BMI for age classification.
Cut offs is as follows; Severe thinness (< -3SD of the median value of the reference population), thinness (<-2SD of the median value of the reference population), normal (>-2SD and <2SD of the median value of the reference population), Overweight (>+1SD of the median value of the reference population) and Obesity (>+2SD of the median value of the reference population).
2.5 Types of Obesity
The accumulation of fat in adipose cells resulting from the excess consumption of calories is different depending on the time of onset and its storage or distribution, obesity is thus classified into four namely:
- Juvenile onset obesity
- Adult onset obesity
- Upper body (Android) obesity and
- Lower body (Gynoid) obesity.
2.5.1 Juvenile onset Obesity
This type of obesity develops in infancy or childhood, and numerous adipose cells develop, each with the ability to grow larger. This presents a special pattern because the greater number of adipose cells may increase the body’s resistance to cutting down fat stores.
Adipose cells have a long life span and apparently need to store some fat. If one adipose cell automatically require more fat storage, reducing total body fat becomes a tough task (Wardlaw, Hamp, Disilvestron, 2004).
2.5.2 Adult onset Obesity
This type of obesity sets in at adulthood, fewer adipose cells are usually present, but these contain an excess amount of fat. Still as it progress in adulthood, adipose cells can increase in number. (Wardlaw et al., 2004).
2.5.3 Upper body (android) Obesity
This is a type of obesity in which fat is stored primarily in the abdominal area and is defined as a waist circumference > 40 inches (102cm) in men and > 35 inches (89cm) in women and is closely associated with a high risk of cardiovascular diseases, hypertension and type 2 diabetes. (Wardlaw et al., 2004).
2.5.4 Lower body (gynoid) Obesity
This type of obesity is one in which fat storage is primarily located in the buttocks and thigh area. This is usually more common in women than in men, as estrogen and progesterone (primarily female hormones) encourage lower body fat storage (Wardlaw et al., 2004).
Of all these types of obesity, the one that is of paramount concern to this study is Juvenile onset obesity (childhood obesity).
2.6 Epidemiology of Obesity
In Africa, initially obesity was not regarded as a health problem in view of the fact that the etiology of obesity revolves around overeating and most Africa nations are poverty stricken and cannot feed their citizens. This is not to say that obesity does not exist here for “it is common knowledge that market women in West Africa are fat”. The story is that urbanization and socio-economic awareness are currently causing a change in the food availability and food habits of many inhabitants. With a resultant effect that there is improved nutrition with the attendant risk of over nutrition and its associated diseases.
The African picture of obesity is some what different when compared with the European. For instance, there is relative obesity seen in the African female which is accepted as a mark of beauty.
Despres, (2001) painted the picture well when he spoke about premarital fattening and joy in accumulation of fat around the buttocks (Steatopygia). In Ghana, Larsson, (2004) showed that serious obesity is prevalent among the women in Accra.
In Yoruba land of Nigeria, a man gains more respect by his sheer size. Among the higher income group, corpulence is symbol of prosperity and abundance, so obesity is not only appreciated but desired Graves, Meyers and Clark (1988).
In Enugu Nigeria, the prevalence of obesity is higher in women than in men. While obesity in men appears to decrease with increasing age, than in women, it shows some linear relationship with age (Okeke, 1988).
2.7 Cultural and Social Significance
Many cultures throughout history have viewed obesity as a flaw. The obesus or fat character in Greek comedy was a glutton and figure of mockery. During the Christian times, food was viewed as a gateway to the sins of sloth and lust (World Health Report 2002). In Western culture, obesity is once again seen as a sign of a low socio-economic status (Crister 2004). They appear unattractive and is commonly associated with various negative stereotypes. Obese people are less likely to be hired for a job, make less money when hired due to inactive nature, and even when eventually hired, they are less likely to be promoted.
As under nutrition is the major concern of most people, over nutrition has also become a major problem among the high income families (Mohammed, 1991). People commonly view weight gain and fat storage as signs of health and prosperity. In the earlier time of hard labour and frequent food storage, securing an adequate energy to meet body energy requirement has the major nutrition concern (Bray 1996).
An Australian study has found that children are more likely to be obese if they are from low income families and the risk is increased further if they are from particular racial background. A study carried out by Associate Professor Dr. Jenny O’Dea in 2002 says her study of 8,500 children is the first to measure the effect of income, social class and ethnicity on obesity and the result revealed that about 9% of the children from low-income families were obese compared to about 4% of children from high-income families. She says the study also found out that children from pacific Island, Middle Eastern, Aboriginal or Southern European background have greater risk of obesity.
“Both low income and being of a certain ethnic background really confers a higher risk of obesity” she said. Compared to the Caucasian white children from, Pacific Island-background who were 4 to 4 ½ times more likely to be obese Middle Eastern children were 4 times more likely, so it really was quite a clear relationship”.
Since the mid-seventies, the prevalence of overweight/obesity has greatly increased for both children and adult (Centres for Disease Control and Prevention). The survey further showed increase in overweight among children and teens. For children aged 2 – 5 years, the prevalence of obesity increased from 5.0% to 13.9%, aged 6-11 years, from 6.5% to 18.8% and 12 – 19 years, from 5.0% to 17.4%. These increasing rates raises a concern because of their implications on victims health.
Today, however, as the standard of living continue to rise, weight gain and obesity are posing a threat to inhabitants of many countries all over the world (WHO, 1998). According to the centres for disease control and prevention (CDC) in the United States nearly 31% of the population is obese, up from 13% in 1960, then from 1980 to 2000, obesity among American adults doubled and the number of obese children and teenagers nearly tripled. Public health officials are concerned that obesity is reaching epidemic proportions. Research on this condition has been much neglected when compared to those of other disease that associated with affluence like diabetes mellitus and cancer (Garrow, 1988). Obesity is a chronic medical problem prevalent in developed as well as in developing countries and affects children as well as adults (Bray, 1996). Obesity is the key risk factor in the natural history of other chronic and other non-communicable diseases particularly in developed countries (WHO, 1998). It is not a recent phenomenon and can be traced to more than 25,000 years ago. The prevalence has never reached such epidemic proportion as today. It has become the major risk, pose. (Eckel, 1992).
Over nutrition with overweight/obesity is mainly found with the healthy people in the developing countries coupled with few cases from the low socio-economic status group that become victims through lack of nutrition education and therefore depend on carbohydrates rich foods that has high caloric values as a result of not being able to afford other nutritious foods (Blundell and King 1999).
Due to the fact that overweight/obesity has been regarded as a sign of attainment of a high social class, it has contributed to the problem of handling this issue especially in the developing Nations where not much study has been done to know its prevalence. Evidence from various studies on overweight/obesity showed that people who reduced their weight live a more longer and healthier life (Garrow, 1991).
An obese person, in several different cultures, is associated with strength, fertility and wealth. In the great Indian epic, the Ramayana, the villain Ravana, has an obese brother named Kumbhakarna who is a strong man with superior fighting qualities.
The laughing Buddha in ancient China is associated with wealth and prosperity. The venus figurines in western culture are obese females, which indicate fertility and those able to survive ferments. The paintings of Rubens (1577 – 1640) are plump female figures suggesting fertility and a symbol of social prestige.
Now an obese individual has unfortunately become a social and cultural out cast. The crude treatment put upon obese people is noticed in the past as well as in the present. An obese is held as somebody with unnatural traits. He or she is often called names. Many times, obese people are considered to be lazy and less intelligent. It is a standard that some members of society have accepted and have unfairly instrumented this falsity into their thinking structure.
In the Shakespearean comedy, “Much Ado About Nothing”, the obese constable Dogberry is called an “Ass” a “Coxcomb” much to the pleasure of the audience. Nobody takes any offence in maltreatment of an obese. The great western comic characters Hardy, in Laurel and Hardy, routinely made fun of issues surrounding his own obesity. The people crowded the movie halls to see the tantrums of Laurel and burst into roars of laughter.
In today’s figure conscious society, an obese is a cultural outcast. The overweight body of an obese with wide waistline is a butt of ridicule. They are always shown in movies and plays, as laughing stocks. In some radical religious beliefs, an obese is even held as a person without soul! The obese are objects of entertainment. In circus, we see jokers and clowns are always short and fat. The obesity of humans has even transformed into animals to get uncensored laughter. Such occurrences are prevalent in cartoon films. Adults and minors are brought together to laugh at the obese creatures.
