Individual and collective factors predicting change in diet quality over 3 years in a subset of older men and women from the NuAge cohort

Purpose This study examined individual and collective factors as predictors of change in global diet quality (DQ). Methods Subjects were 373 older adults (57 % female) aged 68-82 years at recruitment (T1) into the NuAge Cohort Study, and followed for three years. Data were collected by questionnaires, physical performance tests and anthropometric measurements. Diet was assessed at T1 and T4 using three non-consecutive 24-h diet recalls (24HR) and DQ (Canadian Healthy Eating Index), and was computed on the means of the 24HR. DQ change over three years was determined as DQT4-DQT1. Baseline (T1) measures significantly correlated with DQ at T1 were entered into backward stepwise linear regression analyses along with selected theoretical constructs and controlled for baseline DQ to determine predictors of change in DQ over 3 years. Results Among men, education (p = .009) and sensations of hunger (p = .01) were positive predictors of DQ change over time, while DQ at T1 (p < .0001), cognition (p = .003) and social network (p = .019) were negative predictors (adjusted R-2 = 30.4 %). Finally, among women, diet knowledge (p =.044) was a positive predictor of DQ change, while DQ at T1 (p < .0001) and social network (p = .033) were negative predictors of DQ change over 3 years (adjusted R-2 = 24.1 %). Conclusions These results can inform dietary intervention programmes targeting gender-specific determinants of diet quality in older adults.