Dietary Interventions for Adult Survivors of Adolescent and Young Adult Cancers: A Systematic Review and Narrative Synthesis.

Adolescent and young adult (AYA) cancer survivors, here defined as individuals diagnosed with cancer between 15 and 39 years of age, are at high risk for adverse late-term metabolic effects of treatment through adulthood. Diet is a modifiable lifestyle behavior that may improve metabolic health outcomes in AYA cancer survivors. However, the details of dietary interventions for this unique population remain largely undescribed. In this systematic review, we aim to synthesize the results of dietary interventions for adult AYA cancer survivors. Seven databases and clinical trial registries were searched in March 2019 for interventions targeting dietary behaviors in AYA cancer survivors (PROPSERO systematic review number: CRD42019126376). Descriptive statistics and a narrative synthesis were completed to detail intervention participants and components. After full text review of 233 studies, four studies met all inclusion criteria. All studies were heterogeneous for participant age, cancer type, and duration, and were designed for feasibility and preliminary efficacy. Included studies followed different dietary guidance; however, each resulted in a significant change on a primary outcome of either dietary quality or body composition. Three of the four studies included a theoretical framework, where self-efficacy was a central construct. Counseling, in person, telephone, or electronic, provided behavioral support. Results of this systematic review suggest high potential to change dietary behaviors in AYA, but interventions remain limited. AYA cancer survivors demonstrate unique physiological and psychosocial needs, and future interventions designed to address this care gap should be targeted for this population with consideration of social support, delivery mode, and individual tailoring.