Physical inactivity, junk food consumption, and television viewing are the independent variables in this research. Physical inactivity may be operationally defined as the amount of time (average no. of hours/week) devoted to exercise or any other physical activity; television viewing as the amount of time (average no. of hours/week) spent on television watching. Junk food consumption, however, may be operationally defined as the weight (ounces) of average weekly junk food consumption. Obesity in children, operationally defined as the body mass index or weight over height squared of the subjects, is the dependent variable in this research.
This research, however, is not free from extraneous variables or other independent variables which can possibly influence the dependent variable. Food intake, a genetic predisposition for obesity and mental activity have a possible impact on weight gain and therefore, obesity. These variables can be operationally defined as the average weekly calorie count of other consumed foods, the average body mass index of the subjects’ parents and the amount of time (average no. of hours/week) allotted for school and home studying. Food intake has a direct impact on weight gain and therefore, the possibility of childhood obesity.
Genetics predisposes many of our physical, mental, and emotional characteristics. The metabolism rate, which is the rate at which food is broken down and converted into energy, is also hereditary. Some children, therefore, have a genetic predisposition for obesity. Although mental activity has been scientifically-proven to aid in calorie-burning, it cannot be classified as pure physical inactivity nor a strenuous physical engagement. Its inclusion in this research as a possible extraneous variable is therefore necessary.