Plant Protein Intake and Dietary Diversity Are Independently Associated with Nutrient Adequacy in French Adults

Background: Plant protein intake, which is favorably associated with the intake of many nutrients, is a marker of a healthy diet. However, the higher nutrient adequacy of diets rich in plant protein may also originate from overarching factors associated with more healthful dietary behaviors, such as a greater dietary diversity. Objective: Our main objective was to determine whether the relation between plant protein intake and nutrient adequacy could be explained, at least in part, by an association with overall dietary diversity. Methods: We used data from 1330 adults participating in the French Nutrition and Health Survey [Etude Nationale Nutrition Sante (ENNS); 2006-2007]. With the use of global, integrative approaches, we assessed nutrient adequacy (by using the probabilistic PANDiet (Probability of Adequate Nutrient Intake) scoring system] and overall dietary diversity (by using a 100-point score that accounts for the relative number of subgroups consumed in 7 food groups). Linear multivariate modeling was used for the analysis. Results: We found a positive association between plant protein (but not total or animal protein) intake and dietary diversity (beta = 0.08) and a strong positive association between dietary diversity and nutrient adequacy (beta = 0.33). However, the association between plant protein intake and nutrient adequacy was not explained by dietary diversity (r= 0.38 and partial r= 0.36, P < 0.0001). In multivariate analysis, nutrient adequacy was positively associated with dietary diversity (beta = 0.44) and plant (beta = 0.37) and animal (beta = 0.15) protein intakes. Associations persisted after adjustment for potential confounders (total energy, energy density, sex, body mass index, income, occupational status, educational level, region, season, and smoking status). Conclusions: Overall dietary diversity is greater in French adults who consume more plant protein. Both plant protein intake and dietary diversity are associated with the nutrient adequacy of the diet. But the plant protein nutrient adequacy association was not related to the relative overall diversity of the diet.