Exploring culinary diversity to enhance Mediterranean diet adherence: A randomized controlled trial

Abstract

We Investigated how promoting diverse, healthy food options affects long-term dietary choices. We hypothesized that encouraging exploration of nutritious plant-based foods would lead to lasting improvements in diet. Participants (N = 211) were randomly assigned into two groups for a 6-week intervention: The fixed menu group was given the same large menu every week, while the changing menu group received a new small menu each week. At the end of the intervention both groups were exposed to the same menu suggestions. Food diversity evaluation was based on weekly reports collected during the intervention. Self-reported adherence to Mediterranean diet components was assessed using the I-MEDAS screener. The proportion of plant-based foods in participants' diets was estimated using a 0–100% scale based on self-report. Both items were evaluated using online questionnaires given to participants at baseline, at the end of the intervention, as well as three and six months after the intervention concluded. Results mean(SD) demonstrated that participants in fixed menu group explored a significantly wider array of items 26.33(11.64) than those in the changing menus group [19.79(10.29), t(202) = 4.25, p < 0.001, Cohen's d = 0.60]. A repeated measures analysis of covariance rmANCOVA revealed that short-term increase in I-MEDAS and PBD score were noted in both groups; however, only participants with the fixed menu sustained this increase at months follow-up [diff = 1.50, t(132) = 4.50, p < 0.001 Our findings suggest that manipulating the rate of exposure to food suggestions may affect overall dietary variety. It seems that early presentation with options may increase overall dietary variety and may even support longer-term habits. This study contributes to developing effective interventions and highlights the challenge of promoting exploratory behavior in nutrition.