Medical Nutrition Therapy Benefits Patients with Protein-Energy Malnutrition: More Research Needed

Malnutrition is a significant health issue contributing to illness and death. Dietitians play a crucial role in managing malnutrition through medical nutrition therapy, but research about its overall impact on health outcomes is unclear. Funded by the Academy of Nutrition and Dietetics Foundation, a systematic review and meta-analysis was conducted by the Evidence Analysis Center to evaluate the effect of MNT provided by dietitians on nutrition status and key health outcomes compared to no MNT for patients with protein-energy malnutrition.

The review included 11 studies — randomized controlled trials (RCTs) and observational studies — including 86,740 participants. Studies were assessed for quality using Cochrane risk-of-bias tools, and the certainty of evidence was evaluated with the GRADE method. Researchers found that MNT may shorten hospital stays, help maintain or increase weight in patients, and improve quality of life, although the evidence for these outcomes was of low certainty due to differences between the study designs, populations, interventions, and evaluated outcomes (heterogeneity).

The impact of MNT on mortality was inconsistent between the studies, with RCTs showing no significant effect, while an observational study suggested potential benefits. Similarly, the impact on preventing readmissions was unclear in RCTs but appeared beneficial in observational research. Data on other factors, such as calorie and protein intake, body mass index, handgrip strength, and cost-effectiveness remain unclear due to limited data. Differences were observed in the efficacy of MNT in outpatient versus inpatient settings.

MNT provided by dietitians may improve nutrition-related outcomes in hospital settings for individuals with protein-energy malnutrition, but more research is needed, especially in outpatient settings. Despite available nutrition assessment tools [e.g. Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition Indicators (AAIM)] for diagnosing protein-energy malnutrition, their underutilization in healthcare settings persists. Standardizing the diagnosis of malnutrition, involving dietitians in research, and focusing on patient- and payer-relevant outcomes will enable timely nutrition intervention, appropriate nutrition strategies, and improved nutrition and health outcomes.