What is Childhood Obesity? Childhood obesity is when a child gains unhealthy weight according to his/her age and height, although obesity is defined by body mass index or BMI. Moreover, obese children not only face physical health issues. Furthermore, children and teens who are overweight or obese can also become mental problems like depression and face poor self-image and self-esteem, towards society, in schools, or the family. Several studies are sharing multiple information; however, amongst them, these are the collated information: China- 28 million India- 14.4 million United States of America- 13 million Brazil- 5.2 million Mexico- 5.1 million. Conclusion: Children with obesity are a severe health problem where a child started gaining weight and ended up being overweight.