الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Obesity is an excessive accumulation of fat that adversely affects health. It is the result of caloric imbalance (too few calories expended for the amount of calories consumed). In other words, it is an abnormal growth of the adipose tissue due to an enlargement of the fat cell size, an increase in fat cell number or combination of both. Any increase in body weight over the target weight is considered an over weight . Obesity is a disease of complex, multiple causes leading to an imbalance between energy intake and output and to the accumulation of large amounts of body fat. It is measured most often as excessive weight for a given height using body mass index (BMI). The definition of BMI is weight in kilograms divided by height in meters squared. (BMI= weight (kg)/ height (m)2) An obese child: is defined as one with BMI more than +2SD of the reference median, An overweight child is defined as one with BMI more than +1SD of the reference median, child with thinness is defined as one with BMI less than -2SD of the reference line and child with severe thinness is defined as one with BMI less than- 3SD of the reference line. Before the 20th century, obesity was rare. In 1997 the WHO formally recognized obesity as a global epidemic. Once considered a problem only of high income countries, obesity rates are rising world wide and affecting both the developed and developing world. Childhood obesity has more than tripled in the past 30 years. The prevalence of obesity among children aged 6 to 11 years increased from 6.5% in 1980 to 19.6% In 2008 The prevalence of obesity in all age groups has increased dramatically over the past 30 years, such that overweight and obesity are considered to be a major public health concern in many countries. Obesity can be classified in several ways according to: The age at onset of obesity, the anatomic characteristics of adipose tissue, etiologic factors. The causes of obesity are multifactorial, and range from purely genetic conditions, such as leptin deficiency, to entirely environmental conditions. It is however certain that, obesity can only occure when energy intake remains greater than energy expenditure for a long period of time. Thus, if either energy intake increases, or energy expenditure decreases or both, the individual will gain weight. Both energy intake and expenditure are affected by internal homeostatic mechanisms as will as external environmental factors. The national food survey has indicated that there are changes in the types of food that are eaten. There has been a shift from carbohydrate to fat consumption, is the most energy dense macronutrient that cause weight gain. A sedentary lifestyle plays a significant role in obesity. Worldwide there has been a large shift towards less physically demanding work and currently at least 60% of the world’s population gets insufficient
exercise. This is primarily due to increasing use of mechanized transportation and a greater prevalence of labor – saving technology in the home. Appetite and fuel homoeostasis are regulated in feedback circuits involving both regulatory hormones and signaling pathways in the central nervous system and the periphery.Junk food is a slang word for food with limited nutritional value. Every person has his own list of food that he calls junk food. This junk food would include food that is high in salt, sugar, fat or calories and low nutrient content. Salted snack food, candy, gum, most of the sweet desserts, fried fast food and carbonated beverages are some of the major junk food. Generally, they offer little protein, vitamins or minerals and lots of calories from sugar or fat. The term ”Empty calories” reflects the lack of nutrients . Fast food has become a prominent feature of the diet of children and it is increasing throughout the world and obesity is considered now as one of the important predisposing factors for many chronic diseases. Excessive weight has been a problem in developed countries and recently it started to be prevalent in developing world .The adverse medical and psychosocial effects of obesity in children have been well-established. Childhood obesity is also associated with the development of several risk factors for heart disease, including hyperlipidemia, hyperinsulinemia, and hypertension, and other chronic diseases in adulthood. Finally, being overweight as a child increases the likelihood of being overweight as an adult. This present study was across sectional study that carried out on 3619 children aged 6-12 years old 51.6% of the them were males and48.4% were females. Each child in the study was subjected to general examination after taking a precise past medical history anthropometric measurements were done for each child including, weight, height and calculation of body mass index. Finally, wedetermined the socio-economic class of each child according to the modified socio-economic scale for Egyptian families