Firstly, citation required. We need to know how rigorous the study was and whether or not it controlled for other factors such as SES.
Given breakfast's popularity in our society, one would expect that many people who don't have breakfast can't have breakfast - and this is highly correlated with socioeconomic status and poverty, and we've known for a long time that SES is a greater determinant of academic performance than just about any other factor.
In other words, are you sure your study isn't just talking about poor kids not having breakfast, or is it properly controlling for variables?
Given breakfast's popularity in our society, one would expect that many people who don't have breakfast can't have breakfast - and this is highly correlated with socioeconomic status and poverty, and we've known for a long time that SES is a greater determinant of academic performance than just about any other factor.
In other words, are you sure your study isn't just talking about poor kids not having breakfast, or is it properly controlling for variables?