Several limitations in our study should be considered. First, without any information about energy intake or expenditures, it is difficult to identify the behavioral mechanisms that may undergird the link among education, genetic risk, and body mass. The FHS contains information about caloric intake, daily activities (including exercise), and sleep patterns, and additional adjustments for these behaviors may provide a cleaner signal allowing small genetic associations to manifest. However, given the limited support for any consistent genetic associations, it remains unclear whether additional controls would significantly increase the likelihood of finding SNPs that reach genome-wide significance in a sample of this size.
