Schools are positioned to play a key role in nurturing students with knowledge and behaviours associated with healthful living. Our study examined the effects of an intervention on energy balance (EB) knowledge. Twelve 6th and 7th grade classrooms (n = 140) were assigned to receive either two standardised lessons on EB or a combined intervention that featured the same EB lessons, integrated with self-monitoring technology. EB knowledge was pre- and post-measured using a standardised written test, while the situational interest was measured at the end of experiment. Repeated measure analysis of variance and multivariate analysis of variance were conducted, to capture the differences in EB knowledge by time and group, and situational interest by group, respectively. Both groups significantly enhanced EB knowledge over time (F[subscript 1,112] = 11.85; p = 0.001; ?[superscript 2] = 0.10), but the combined group demonstrated a greater increase (F[subscript 1,112] = 5.36; p = 0.02; ?[superscript 2] = 0.05). An item-by-item mean comparison of EB knowledge and correct percent scores confirmed the above result (i.e. combined group versus education group: 7% versus 2% EB knowledge increase).The two groups were equally motivated to participate in the experiment, showing similar levels of total interest (education group: M/SD = 4.00/0.68; combined group: M/SD = 4.17/0.74; p = 0.18). The research findings and their implications are discussed.