Obesity is a disease that can be defined by an accumulation of abnormal and excessive fat mass in the body, disease caused by an imbalance of food associated with a lack of activity, it can be of different types and degrees also obesity is considered an important public health problem in many countries, it has very heavy consequences for health. By 2025, estimates predict that obesity will affect half of all men and one third of all women. In Morocco, one in ten Moroccan children and adolescents are affected by obesity. The scourge would affect 10.3% of boys and 9.9% of girls aged 5 to 19 years. And also the rate of obesity among 5-19 year olds has increased from 4.4% in 2000 to 10% in 2015. From these worrying figures our study is conducted to identify all the factors that influence in a direct or indirect way to this pandemic using a survey intended for 200 schoolchildren aged 6 to 12 years at the level of the region of Kenitra and Khemisset and the results obtained (200 questionnaire formed by simple sentences since it is intended for children and it is by closed and open questions according to the nature of the expected response), The data are processed by SPSS software which allowed us to discover that at the level of this region, childhood obesity affects the female gender more than the male gender, also in total more than 60% of schoolchildren suffer from this pandemic, the genetic factor influences the appearance of obesity by a percentage that can reach 40%, without forgetting the relationship between obesity and the dietary factor which can be summarized by the impact of the number of meals per day (71% consumes 3 meals per day and 20, 5% consume more than 3 meals a day), the consumption of fast food (64% of the children consume fast food more than 3 times a week) and sugary drinks (69% of the children consume sugary drinks a lot) on the weight gain, the impact of the behavioral factor which is reflected in the bad snacking (92, 5% of the children snack in a bad way) and the lack of sleep (this factor influences indirectly what is noticed is that 93% of the respondents do not have a stable sleep schedule) and then the sedentary lifestyle which is the most intense cause of childhood obesity. This factor is generally translated by the hours spent in front of the screen and the number of times of practicing sports per week (27% of the children who practice a sport 2 times per week with a percentage of 62, 5% while the time spent in front of the screen exceeds 1 hour per day with a percentage of 79%).

What is concluded is that the main factors of obesity in children in the Rabat/Salé/Kenitra region are sedentary lifestyle and bad behavioral habits.

Keywords-Obesity, childhood obesity, responsible factor, statistical study, Morocco