Low protein content of plant-derived nutrition limits the protein transition in hospitalized patients: Results from an observational study

Background & aims: To improve global- and environmental health, the Dutch Green Deal Sustainable Healthcare (DGD) guidelines recommend to replace at least 50 % of animal protein with plant-derived protein. This may be a challenge for hospitalized patients due to the low protein content and the lack of Essential Amino Acids (EAA) in individual plant-derived sources in combination with anabolic resistance during disease. Yet, there is little knowledge about the effect on protein- and amino acid intake among hospitalized patients as we shift to more plant-derived diets. Therefore, this observational study examines (plant- and animal) protein intake and Amino Acid Scores (AAS) of predominantly plant- and animal derived meals in a large university hospital. Methods: Food intake data were collected through direct observation in non-critically ill adult patients between October and November 2023. Protein requirements were set on 1.2 g/kg body weight, adjusted for BMI. For data analysis, patients were divided into three groups based on their total protein intake: low (<0.8 g/kg), moderate (0.8–1.1 g/kg) and adequate (≥1.2 g/kg). Meals were considered predominantly plant-derived if plant protein (in grams) accounted for over 50 % of its total protein content. AAS were determined per meal by assessing the amount of EAA per gram of protein relative to EAA requirements. Results: In total, 234 patients were included. Protein intake was insufficient in 80 % of all patients. The overall animal-to plant protein ratio was 69:31. Among patients who consumed more than 50 % plant-derived protein per meal, lysine was the most common limiting amino acid (AAS <1). In contrast, no limiting AAS per gram of protein were found for patients consuming more than 50 % animal-derived protein per meal. Conclusion: Achieving sufficient protein intake (1.2 g/kg) is a key challenge especially in the shift towards more plant-derived nutrition. Although the predominantly plant-derived meals require careful attention to amino acid profiles, especially for lysine, the low total protein content of predominantly plant-derived meals poses the greatest challenge, thereby limiting the feasibility of the protein transition for hospitalized patients.