Egg Consumption in the Context of Plant-Based Diets and Diet Quality in Adults at Risk for Type 2 Diabetes: A Randomized Single Blind Cross-over Controlled Trial

Background: Lifestyle changes that emphasis on plant-based diets (PBD) are typically recommended for those at risk for type 2 diabetes mellitus (T2DM) to mitigate their cardo-metabolic risk. We examined the impact of the inclusion of eggs compared with their exclusion from PBD on diet quality among adults at risk for T2DM. Methods: This was a randomized, controlled, single-blind, crossover trial of 35 adults (mean age 60.7 years; 25 women, 10 men; 34 Caucasians, 1 African-American) at risk for T2DM (i.e., pre- diabetes or metabolic syndrome) assigned to one of two possible sequence permutations of two treatments (PBD with eggs and exclusively PBD), with a 4-week washout period. Participants received dietary counseling from a dietitian to exclude or to include 2 eggs daily in the context of PBD for a 6-week period. Diet quality was assessed using the Healthy Eating Index 2015 (HEI-2015) at baseline and 6 weeks. Results: Compared with the exclusion of eggs, the inclusion of eggs in the context of PBD improved the diet quality score for intake of total protein foods (1.0 +/- 1.1 vs. -0.4 +/- 1.0; p <.0001); seafood and plant proteins (0.2 +/- 1.2 vs. -0.4 +/- 1.1; p = 0.0338); and fatty acids (0.8 +/- 2.5 vs. -0.7 +/- 2.7; p = 0.0260). Overall diet quality score depreciated with the adoption of exclusively PBD without eggs (-3.1 +/- 8.3; p = 0.0411), while it was unaffected with the adoption of a PBD with the inclusion of eggs (-0.6 +/- 7.9; p = 0.6892). Conclusions: Eggs could be used as an adjuvant to enhance the diet quality among those at risk for T2DM who adopt plant-based dietary patterns.