Protein Malnutrition

The goal of this clinical trial is to determine whether meals fortified with plant-based high protein sauce (ProSauce) provide better metabolic availability of essential amino acids compared to meals with standard lower-protein sauce without resulting in excessive gut fullness and satiety. The main questions it aims to answer are: Does meals with high-protein sauce deliver better metabolic availability of amino acid profile? Does this high-protein sauce also not lead to excessive appetite suppression due to its liquid form? Researchers will compare high protein sauce to a commercially available standard low protein sauce. Participants will consume two meals, either protein-fortified or standard low-protein sauce, in a randomised order with at least a one-week washout period between each meal. The investigators will collect venous blood samples over a 6-hour postprandial period to measure plasma essential (and non-essential) amino acid and insulin concentrations. The investigators will also measure appetite-related hormones from venous plasma and assess subjective appetite using a visual analogue scale, taken in parallel with the blood sample time points.

This prospective observational randomized study aims to determine energy, protein intake and gastrointestinal tolerance while using enteral nutrition formulas with very high protein content and enteral nutrition formulas with normal protein content. * Differences regarding achieving protein and calorie daily targets when using enteral nutrition formulas with different protein content * Differences regarding residual gastric volume when using enteral nutrition formulas with different protein content * Differences regarding body composition when using enteral nutrition formulas with different protein content

Protein malnutrition in critically ill patients is a global concern due to its association with prolonged hospital stays, and higher morbidity rates. Patients who undergo abdominal surgery are particularly vulnerable due to alterations in gastrointestinal function and prolonged fasting. Despite the significance of proper nutrition, the optimal target of protein supplementation remains controversial. The investigators aimed to evaluate the effects of high protein provision, targeting a protein intake of at least 1.5 g/kg/day for the first 3 days after abdominal surgery, on 6-month mortality.