The relationship between nutrition and physical activity knowledge and body mass index-for-age of school-aged children in selected schools in Ghana.

Background Nutrition knowledge contributes significantly to the nutritional status and habits of individuals as it influences their food consumption. And body mass index (BMI) of individuals. Recent data suggests a relationship between nutrition and physical activity knowledge, attitude, practices, and anthropometric indices of Ghanaian children. Objective To determine the relationship between nutrition and physical activity knowledge and using BMI-for-age of school-aged children. Methods A cross-sectional study involving 591 school-aged children (8-13 years) chosen at random from schools in Ghana's Ho Municipality. Socio-demographic information was gathered. Data on nutrition and physical activity knowledge, attitude, and practice were also collected using structured questionnaires. BMI was calculated after weight and height were measured. Results Majority of the participants had poor knowledge on nutrition (46.6%) and physical activity (49.8%) even though more children in private schools (63.3%) had better (good and excellent) knowledge in nutrition than children from public schools (48.2%). Older children (11-13 years) had 'good' knowledge of physical activity (54.7%) as opposed to younger children. Males (59.5%) and children in private schools (66.3%) also had better overall scores in combined nutrition and physical activity knowledge than their female and public-school counterparts, respectively. Physical activity knowledge was significantly (p < 0.05) associated with the BMI-for-age categories. Nutrition knowledge (p < 0.05) and total nutrition and physical activity knowledge scores (p < 0.001) were weakly but positively associated with BMI-for-age. Conclusion The results suggest that BMI-for-age of the participants was positively correlated to the nutrition knowledge and the total nutrition and physical activity knowledge (NutPA).