Effectiveness of Medical Nutrition Therapy Provided by Dietitians on Nutrition and Health Outcomes in Adults with Protein-Energy Malnutrition: A Systematic Review and Meta-Analysis.

Abstract

Background: Malnutrition is associated with increased morbidities and mortality.

Objective: The aim of this systematic review and meta-analysis was to evaluate the effect of medical nutrition therapy (MNT) provided by a dietitian, compared to no MNT on nutrition status and health outcomes (mortality, length of stay (LOS), readmissions, quality of life (QoL), weight, physical function, and cost-effectiveness) in adults with protein-energy malnutrition (PEM).

Methods: MEDLINE, CINAHL, Cochrane Central, Food Science Sources and SPORTDiscus databases were searched for observational and controlled trials published in English in peer-reviewed journals from 2000-September 2024. Risk of bias (RoB) was assessed using Cochrane RoB tools for randomized controlled trials (RCT) and observational studies. Meta-analyses were conducted using the DerSimonian-Laird random-effects model. Certainty of evidence (COE) was assessed using the Grading of Recommendations, Assessment, and Evaluation (GRADE) method.

Results: Fifteen articles representing 11 studies (9 RCTs, 1 non-randomized controlled trial, 1 retrospective cohort) with 86,740 participants were included. RoB for included studies were low (1 study), some concerns (7 studies), high (3 studies). MNT may decrease LOS, increase weight (inpatient), and improve QoL (inpatient) (Low COE). In adults with PEM the effect of MNT on nutrition status, calorie and protein intake, body mass index, handgrip strength, and cost-effectiveness is uncertain. The effect of MNT on mortality was uncertain in outpatient settings and conflicted in inpatient settings, with no effect in pooled RCTs (Low COE) and reduced mortality in an observational study (Moderate COE). Its effect on readmissions was also uncertain in an RCT but may reduce readmissions according to an observational study (Moderate COE).

Conclusion: MNT may improve some outcomes (LOS, hospital readmissions, weight, QoL) in inpatients with PEM, but evidence is uncertain for most outcomes (nutrition status, mortality, weight, handgrip strength, QoL) in outpatient settings and requires more research.