Computer Engineering and Intelligent Systems www.iiste.org ISSN 2222-1719 (Paper) ISSN 2222-2863 (Online) Vol.6, No.9, 2015 21 Design Methodology of Fuzzy Expert System for the Diagnosis and Control of Obesity Uduak Umoh Department of Computer Science, University of Uyo, Uyo, AKS, Nigeria Etebong Isong Department of Computer Science, Akwa Ibom State University, Mkpat Enin, AKS, Nigeria Abstract Both developed and developing nations of the world have overtime experienced enormous increase in food and other consumables production. This has led to a rise in calorie intake by people living in these nations of the world. As calorie intake increases in the human system, lack of early detection or control leads to obesity. The study of obesity is gaining utmost importance because of the major health issues associated with it. If an obese prone patient is detected early enough, then quite a number of diseases can be prevented. The ability of fuzzy logic to reason with uncertain and imprecise data in addressing the specific problem of diagnosis and monitoring of diseases in our society cannot be over emphasized. In this paper we design methodology of fuzzy expert system to diagnose and monitor obesity in persons at early stage. The study will help reduce to a great minimum the fast rise of obesity in our society and the world at large. The proposed study is validated with MatLab, and is used as a tracking system with accuracy and robustness. Keywords: Obesity, Fuzzy Inference System, Body Mass Index, Body fat, Waist circumference. 1. Introduction Both developed and developing nations of the world have overtime experienced enormous increase in food and other consumables production. This has led to a rise in calorie intake by people living in these nations of the world. As calorie intake increases in the human system, lack of early detection or control leads to obesity. The foods we eat every day contribute to our well-being. Foods provide us with the nutrients we need for healthy bodies and the calories we need for energy. If we take in more calories than we burn, the extra food turns to fat and is stored in our bodies. If we overeat regularly, we gain weight, and if we continue to gain weight, we may become obese. To reduce these risks, much attention is being paid to methods of weight loss in Nigeria, and there is increasing awareness of the need to monitor caloric and nutrient intake, as well as an emphasis on the healthiness and balanced nature of food intake Obesity results from the accumulation of excess fat on the body. It has many serious long-term consequences to health, and it is a leading cause of preventable deaths in the world. Obesity is defined as having a body mass index (BMI) of greater than 30. The BMI is a measure of your weight relative to ones’ height. BMI is a mechanism to measure weight excess extensively used in a myriad of epidemiologic studies, and is incorporated with clinical practice because of its simplicity. However, it does not properly evaluate the body fat (BF) proportion because it fails to distinguish lean muscle mass from body fat. The BF measurement has more value than global body mass measurements since the harmful factor in obesity is the accumulation of fat in the body, and lean muscle mass. More than two-thirds of Americans are overweight, including at least one in five children. Obesity is on the rise in our society because food is abundant and most of us are employed in positions that require little to no physical activity. On the bright side, recent data suggest that childhood obesity, while still high, may no longer be on the rise (Eknoyan, 2008) (Okorodudu, 2010). The study of obesity is gaining utmost importance because of the major health issues associated with it. A lot of sicknesses arise due to obesity, such as diabetes, high blood pressure, cholesterol, stroke etc. If an obese prone patient is detected early enough, then quite a number of diseases can be prevented. The use of the body mass index calculator has done quite a job but it does not guarantee the complete detection of obesity as other factors such as genetic line are not considered in the body mass calculator (Adams et al. 2007) . The major problem in diagnosing and predicting a disease is the uncertain variations in risk factors which occur due to the sedentary life style, food habit, stress, age, environment etc. Generally the risk factors in medical domain are classified as controllable (Blood Pressure, Lipids, Obesity, Hyperglycemia), non-controllable (age, heredity, sex) and contributing factors (smoking, alcohol, stress). Due to uncertainty, information is incomplete,