Finally, we tested whether BMI was associated with change in personality. Detailed information about normative changes in personality across the adult lifespan in the BLSA can be found in Terracciano and colleagues (2005). Using HLM, we estimated the rate of change in personality and then tested whether BMI was associated with this trajectory.3 There were 6,824 valid assessments of personality, with an average of 3.42 assessments per participant (SD = 2.47, range = 1 to 16). Adiposity was primarily unrelated to change in personality: BMI was not associated with the slope of any of the five broad domains. The other three measures of adiposity were also unrelated to change in the five factors. At the facet level, higher BMI was associated with decreases in N5: Impulsiveness (b = −.08 [SE = .02], p < .01). This effect replicated across waist circumference, hip circumference, and body fat. BMI was unrelated to change in any of the other facets. Sex did not moderate the association between BMI and the trajectory of personality.
