The purpose of this study is to know the correlations of maternal competence, physical activity, and consumption of junk food with the incidence of obesity in toddlers in the Work Area Puskesmas Bahu Kecamatan Malalayang Manado City. This research is an explanatory research (Explanatory Research). The total sample in this study was 98 children under five. The results showed no relationship between maternal competence with obesity characterized by p value 0.072. There is no relationship of junk food consumption with obesity characterized by p value 0.132. There is a relationship of physical activity with junk food consumption characterized by p value 0,132. There is a relationship of physical activity with junk food consumption marked with p value 0.000. There is a relationship of physical activity with obesity characterized by p value 0,016. There is a relationship between mother's competency and physical activity with a p value of 0,000. There is relationship of mother competence with junk food consumption marked with p value 0,011. regular nutrition counseling activities for children, parents, school teachers with extension materials, among others: more nutritional problems, including prevention, and impacts, healthy food choices, healthy consumption habits, and good activity patterns. Keyword: Mother Competence, Physical Activity, Consumption of Junk Food, Obesity