Background: Childhood obesity is an important public health concern associated with unhealthy dietary practices, physical inactivity, sedentary behaviour, and other lifestyle-related factors. School health education provides an opportunity to improve children’s understanding of obesity and promote healthy behaviours at an early age.

Aim: To assess the effectiveness of a planned teaching programme on knowledge regarding the causes and consequences of obesity among school-going children in a selected school.

Methods: A quantitative research approach with a pre-experimental one-group pre-test and post-test design was adopted. Sixty school-going children aged 6–11 years were selected using a non-probability convenience sampling technique. Data were collected using a self-structured knowledge questionnaire consisting of 20 items. A planned teaching programme was administered after the pre-test, and the post-test was conducted on the seventh day. Descriptive statistics and a paired t test were used for analysis. The questionnaire demonstrated a reliability coefficient of 0.86.

Results: In the pre-test, 15.0% of children had poor knowledge, 85.0% had average knowledge, and none had good knowledge. The mean pre-test knowledge score was 9.78 ± 2.38. Following the planned teaching programme, no child had poor knowledge, 58.33% had average knowledge, and 41.67% had good knowledge. The mean post-test score increased to 14.08 ± 1.96. The paired t test was 12.63 with p

< 0.001.

Conclusion: The findings demonstrate a significant improvement in knowledge following the planned teaching programme. School-based health education may be incorporated into school health activities to improve awareness regarding obesity and its prevention among children.