Diversity of Plant-Based Food Consumption: A Systematic Scoping Review on Measurement Tools and Associated Health Outcomes.

A scoping review of the literature was conducted to identify studies investigating plant-based food diversity and human health outcomes. Objectives were to (a) explore definition(s) of plant-based foods used, (b) identify assessment tools used to measure plant-based food consumption, (c) characterize the assessment tools and methodology used to measure the diversity of plant-based food consumption, and (d) identify the health outcomes that have been investigated in relation to the diversity of plant-based food consumption, and explore the findings. Consumption of diverse plant-based foods provides a rich source of nutrients and nonnutrient bioactives that are often reported to improve health outcomes. Despite this, there are no standard definitions of plant-based food diversity, there is no consensus on methods of measurement, and there is limited understanding of its associated health benefits. Eligible studies were those investigating the relationship between plant-based food diversity and any health-related or lifestyle outcome, by any study design, in high income countries only. Studies were identified by systematic searches of 2 electronic databases and manual searches of reference lists. No restrictions were applied for language or year of publication. Forty-three studies were eligible for inclusion in this review. The majority of the studies were observational in design (38/43; 88%) and included fruits and vegetables only in their definitions of plant-based food diversity (31/43, 72%). Methods of measurement of both plant-based food intake and diversity varied greatly between studies, with only 3 (7%) articles reporting the use of a dedicated tool for assessment of plant-based food diversity in their population of interest. Health outcomes assessed included dietary intake and behavior, cardiometabolic risk factors, socioeconomic determinants of health, and cancer risk. There is a need for a robust definition and standardized assessment tools for plant-based food diversity. Observational studies have found associations between plant-based food diversity and certain health outcomes that warrant investigation in future randomized controlled trials.