The Genome-Wide Influence on Human BMI Depends on Physical Activity, Life-Course, and Historical Period

Guang Guo, University of North Carolina at Chapel Hill
Hexuan Liu, University of North Carolina at Chapel Hill
Ling Wang, University of North Carolina at Chapel Hill
Haipeng Shen, University of North Carolina at Chapel Hill
Wen Hu, Beijing University

In this analysis, guided by an evolutionary framework, we investigate how the human genome as a whole interacts with historical period, age and physical activity to influence BMI. The analyses draw analysis samples from a pool of > 8,000 individuals in the Framingham Heart Study and produce three empirical findings. First, the genomic influence on BMI is substantially and significantly larger after the mid-1980s than in the few decades before the mid-1980s within each age group of 21-40, 40-50, 51-60 and >60. Second, the genomic influence on BMI weakens as one ages across the life course or the genome influence on BMI tends to be more important during reproductive ages than after reproductive ages within each of the two historical periods under consideration. Third, within the age group of 21-50, the genomic influence on BMI among physically active individuals is statistically significantly and noticeably smaller than the influence on those who are not physically active.