Dietary trajectory profiles of French adults over time: Multicriteria analysis of sustainability

Abstract Despite the urgent need for sustainable dietary transitions, few studies have examined current dietary trajectories using longitudinal data. This study aimed to identify dietary consumption trajectory profiles over an 8-year period (2014-2022) while assessing their sustainability in a multicriteria approach. Consumption data from NutriNet-Santé cohort participants were collected using FFQs in 2014, 2018 and 2022. Dietary trajectory profiles were modeled using group-based multi-trajectory based on factors from Principal Component Analysis on energy-adjusted consumption data (n = 17,187). Profiles were analyzed for sustainability (environmental and nutritional dimensions) using multi-adjusted mixed-effects models. Six trajectory profiles (P) were identified. P0 (considered as reference) had average consumption for all food groups, with increased plant-based intake over time. In comparison, P1 had the highest baseline alcohol (+301%) and offal intake, increasing processed meat (+74%) and decreasing offal over time. P2 had higher milk (+187%) and sweet drinks intake, increasing animal substitutes (+1737%) and whole-grain products. P3 had higher nuts (+680%) and legumes intake, increasing egg (+166%) and reducing fruit juice. P4 had high fish (+39%) and fruit intake, increasing butter (+53%) and reducing alcohol. P5 had higher pork (+143%) and red meat intake, increasing fish (+31%) and reducing dairy. Initially, P3 and P4 had the lowest GHG emissions (-18%, -49% vs. P0), best nutritional profiles, and higher organic food consumption. P5 had the greatest environmental impact (+51%) and the lowest nutritional scores. Over time, P0 reduced GHG emissions and improved nutritional scores. P3 and P4 showed minimal changes, while P5 had the greatest GHG emissions decrease (-14%) and nutritional quality improvements. Identifying ongoing dietary transition trajectories, our findings contribute to optimizing targeted actions aimed at promoting sustainable dietary consumption habits. Key messages • Regardless of initial dietary preferences, French adults exhibit an overall trend over time towards increased intake of plant-based foods and decreased intake of red meats, at varying scales. • French adults exhibit varying degrees of transition towards more sustainable diets, with an overall decrease in GHG emissions from food consumption and an improvement in their nutritional profiles.