**Background:** Poor dietary quality is a leading cause of morbidity worldwide, making the promotion of healthy eating a public health priority. Older adults are a critical target group due to increasing chronic disease risk with age and the potential for dietary change during life transitions. Food neophilia—the willingness to try unfamiliar foods—has been suggested as a factor that may promote healthy eating, but prior evidence was exclusively cross-sectional and limited to brief dietary screening tools. No study had examined the longitudinal reciprocal relationship between food neophilia and dietary quality in older adults.
**Methods:** This two-wave longitudinal study analyzed data from the NutriAct Family Study (NFS), a web-based, prospective, interdisciplinary study. Participants aged 50 years and older (N = 960, M_age = 63.4 years, range 50–84) from 409 families completed questionnaires at T1 (January 2017–March 2019) and T2 (September 2020–November 2021), with a mean interval of 40.0 months (SD = 4.2 months). The dropout rate was 13.6% (N = 829 at T2). Food neophilia was measured using the German version of the Variety Seeking Tendency Scale (VARSEEK), an 8-item instrument rated on a 7-point Likert scale (Cronbach's α = .93 at both waves). Dietary quality was assessed using the NutriAct diet score (range 0–10), an evidence-based scoring scheme based on 10 food groups associated with chronic disease prevention, derived from a combination of 24-hour food lists and an EPIC-Potsdam Food Frequency Questionnaire. The stringency of COVID-19 government containment policies at T2 was quantified using the Oxford COVID-19 Government Response Tracker stringency index (M = 64.65, SD = 11.98, range 42.59–85.19). Statistical analyses included confirmatory factor analyses to establish measurement invariance of food neophilia across waves, followed by a cross-lagged panel analysis using structural equation modeling with robust maximum likelihood estimation and a type "complex" option to account for family clustering. Covariates included gender, age, BMI, educational status, and pandemic stringency. Multiple imputation (50 datasets) was used for missing data.
**Key Results:** Food neophilia showed a significant but small mean decrease from T1 to T2 (Wald(1) = 23.13, p < .001, d = 0.31), while dietary quality showed no significant mean change (Wald(1) = 0.39, p = .531). Bivariate correlations revealed small positive associations between food neophilia and dietary quality at both time points (r = .10–.13 range). The cross-lagged panel model demonstrated good fit (CFI = .953, RMSEA = .054, SRMR = .039). Both constructs showed high longitudinal stability: food neophilia at T1 strongly predicted food neophilia at T2 (β = 0.80, p < .001), and dietary quality at T1 strongly predicted dietary quality at T2 (β = 0.65, p < .001). The model explained 67.0% of variance in food neophilia and 44.5% of variance in dietary quality. Food neophilia did not have a significant prospective effect on dietary quality. Dietary quality showed a very small positive prospective effect on food neophilia. Exploratory multigroup comparisons by weight status revealed that the positive cross-sectional correlation between food neophilia and dietary quality was significant only in individuals with overweight/obesity (BMI ≥ 25 kg/m²), not in those with normal weight (BMI 18.5–24.9 kg/m²). Post-hoc Wald tests confirmed a significant difference between weight status groups in this cross-sectional correlation (Wald(1) = −0.26, p = .002).
**Clinical Implications:** This study provides the first longitudinal evidence on the stability and interrelationship of food neophilia and dietary quality in older adults. The high stability of both constructs suggests that interventions aimed at modifying either food neophilia or dietary quality in later life may face challenges, as established patterns are resistant to change. The absence of a prospective effect of food neophilia on dietary quality indicates that simply promoting willingness to try unfamiliar foods may not be sufficient to improve overall dietary quality in older adults. Instead, interventions might need to specifically target food neophilia toward nutrient-rich, health-promoting foods. The finding that the food neophilia–dietary quality association was significant only in individuals with overweight/obesity suggests weight status may moderate this relationship, potentially identifying a subgroup where food neophilia-oriented interventions could be more effective. The moderate dietary quality scores observed overall underscore that older adults remain an important target group for dietary interventions to reduce chronic disease risk. Future research should explore developmental trajectories of both constructs, potential critical windows for intervention (e.g., during life transitions such as retirement), and mediating variables such as cooking skills and nutrition knowledge.