Breakfast, plasma glucose and beta-hydroxybutyrate, body mass index and academic performance in children from Extremadura, Spain.

OBJECTIVES Nutritional aspects of breakfast, plasma levels of glucose and beta-hydroxybutyrate, body mass index and academic performance have been studied in urban and rural children (Extremadura, Spain). METHODS Representative samples of schoolchildren (3 to 12 years old, random cluster-sampling in schools). RESULTS Children's mean caloric intake with breakfast was 331 kcal. Rural population ingested more carbohydrates (46,9 +/- 12,3% versus 43,3 +/- 13,2% of the total caloric intake) and fewer lipids (40,5 +/- 11,8% versus 43,9 +/- 12,8% of the total caloric intake) than the urban population. Academic performance was significantly better in the children inhabiting the rural zone than in those of the urban zone. The glycaemia was higher in the urban than in the rural children, and that the contrary was the case for the beta-hydroxybutyrate values. Neither glucose nor beta-hydroxybutyrate levels were correlated with academic performance values. BMI was significantly increased in the urban versus rural children. CONCLUSION The present results emphasize the importance of breakfast and life style in the weight and the academic performance of children.