Asymmetry of spectral power (SP) of frontal EEG α-activity (FAA=(SP(F4)-SP(F3)/(SP(F4)+SP(F3)) is a marker of an individual’s emotional background, and of his/her reward (RS) and punishment sensitivity (PS) in motivational processes. A positive FAA value (FAA>0) points at greater left-hemispheric frontal cortex activity in relation to the right-brain and speaks of a positive emotional background of the individual, his/her RS and tendency toward goal approach behavior. Greater activity of the right-brain frontal cortex is associated with vulnerability to depression and anxiety, and a PS as well as avoidance behavior. Healthy RS subjects have enhanced mental flexibility (MF). On the other hand, it is assumed that FAA points at the motivational orientation of behavior (approach vs. withdrawal) irrespectively to associated emotions. To explore interrelationships amongst anthropometric markers of obesity, school anxiety (SA), school performance (SP), MF, emotional eating (EE), and FAA, girls aged 9-10 without psycho-neurological diagnoses were studied: 27 with obesity and 23 with normal weight. The obese girls had lower scours for SP. Positive link between the waist-to-hip ratio and SA was established. No links were found among FAA, SA and BMI. However, a split correlation analysis revealed, that in the lean girls, the BMI is inversely related with FAA (p=0.06), and FAA has a negative correlation with SA and EE. In the obese girls, to the contrary, BMI positive liked to FAA, while FAA had an inverse correlation with MF, which perhaps speaks of RS in obese girls, and of their reduced ability to inhibit desirable but risky behavior like over-eating.