This article referenced several different studies, toying with and moderating certain factors such as aptitude, previous academic performance, and study habits in relation to whether one eats breakfast regularly, wake-up times, etc.
Weekday and weekend wake-up times had the largest relative effects on semester GPA, the reality being for each hour of delay in the reported average weekday wake-up time, the predicted GPA decreased by a little more than 0.13–that really struck me, personally.
I think that it’s telling that Perko observed that the lower the GPA, the more likely it was that college athletes would ‘engage in poor lifestyles and health-threatening habits’, because it relates to Haine’s report that measures of depression in college students were ‘negatively correlated with academic performance.’ So in my mind, in a way, those with poorer GPAs are more prone to be disheartened and to give in when it comes to upcoming assignments.
What I took away from the article and these studies is that there are an infinite number of potential control groups and elements that could be experimented with. But ultimately, those with consistent habits, consistent sleep cycles, consistent diet, and a healthy social support system succeed in college.