International Journal of Public Health Science (IJPHS) Vol. 10, No. 3, September 2021, pp. 679~687 ISSN: 2252-8806, DOI: 10.11591/ijphs.v10i3.20928  679 Journal homepage: http://ijphs.iaescore.com Examining child obesity risk level using fuzzy inference system Febrina Sari 1 , Desyanti 2 , Teuku Radillah 3 , Siti Nurjannah 4 , Julimar 5 , Juwita Yanti Pakpahan 6 1,2 Department of Informatics Engineering, Sekolah Tinggi Teknologi, Dumai, Indonesia 3 Department of Engineering, AMIK Mitra Gama, Duri, Indonesia 4,5,6 Nursing Study Program, Akademi Keperawatan Sri Bunga Tanjung, Dumai, Indonesia Article Info ABSTRACT Article history: Received Mar 7, 2021 Revised Jun 13, 2021 Accepted Jun 21, 2021 The doctor will determine the risk level of childhood obesity by using standard calculations, namely measuring the child's weight and height, and many other factors. Then the doctor will calculate the child's body mass index (BMI). The results of calculations made by the doctor will be compared with standard/normal values set by FAO/WHO, to obtain the level of risk of obesity in children. This study aims to analyze the risk level of obesity in children using the Sugeno method of Fuzzy Inference system, using the trapezoidal membership function and involving six input variables such as exercise habits, consumption of fast food, history of obesity of parents, and others. The application of the fuzzy inference system Sugeno method can help doctors to analyze the risk level of childhood obesity quickly and accurately with an accuracy rate of 85%. The results of the implementation of the Sugeno method of Fuzzy Inference system showed that out of 140 children who were the object of the study, 119 children received a diagnosis of the level of risk of obesity which was the same as the diagnosis made by a doctor. Keywords: Body mass index Depression Fuzzy logic Obesity Sugeno method This is an open access article under the CC BY-SA license. Corresponding Author: Febrina Sari Department of Informatics Engineering Sekolah Tinggi Teknologi Dumai Street Utama Karya Bukit Batrem II, South Dumai, Riau, Indonesia Email: febri_ghaniya@yahoo.co.id 1. INTRODUCTION Obesity is one of the problems in the world of health which is better known as obesity [1], [2] without realizing it, the risk of obesity in children is getting higher with the ease of getting fast food such as burgers, pizza, soft drinks and junk food that are available in food outlets [3], [4]. Obesity is a condition of excessive weakness in the body which is often expressed in terms of fat or overweight [2], [5] overweight reaches 20% of the standard bodyweight. Obesity also occurs as a result of an imbalance between the amount of incoming energy and that required by the body for various biological functions such as physical growth, development, and activity [6], [7]. Obesity in children can have an impact on the development of the child as a whole, the physical impact that can occur, such as type 2 diabetes mellitus [8], [9], high blood pressure, cholesterol in the blood which can form plaque in arteries [10] which can lead to heart attacks or strokes [11]. Meanwhile, the psychological impact, such as experiencing bullying or oppression and loss of self-esteem that causes feelings of hopelessness and results in depression. In addition, being overweight can also result in a decrease in the level of intelligence of children, this is because the activity and creativity of children are decreased and tend to be lazy. The doctor will determine the level of risk of obesity in children by measuring the child's weight and height, then the doctor will calculate the body mass index (BMI) [12]. These results will be