Dietitian-Provided Interventions for Adults with Cancer: An Umbrella Review of Systematic Reviews

Malnutrition is common in adults with cancer and is associated with lower quality of life and higher risk of mortality. A comprehensive picture of dietitian efficacy in cancer care is needed to inform payers and policymakers about effective care options. The objective of this umbrella review of systematic reviews (SRs) is to examine the impact of dietitian interventions, compared to no intervention or usual care, on nutrition-related outcomes in adults with all types and stages of cancer. MEDLINE, CINAHL, Cochrane Database of SRs, Food Science Source, and SPORTSDiscus databases were searched for SRs and meta-analyses published from 2018 to September 2024. The GRADE method was used to rate evidence certainty. There were 2,087 articles identified in the search, 125 full texts were examined for eligibility, and seven SRs were included in this umbrella review, representing 25 randomized controlled trials and six observational studies. Interventions provided by dietitians may improve nutrition status, protein and energy intake, length of stay, and quality of life, but evidence certainty was low, primarily due to the risk of bias in primary studies, heterogeneity, and lack of precise effect size. Providing dietitian-led interventions for adults with cancer may improve a wide range of nutrition-related outcomes.