(P21-08-26) The Vegetarian Lifestyle Index and Nutritional Adequacy in the Cancer Prevention Study-II Nutrition Cohort

Objectives: Plant-based dietary indexes are often estimated from population intake levels. Since dietary guidelines define target intake levels for optimal health, this study assessed nutritional adequacy across Vegetarian Lifestyle Index (VLI) scores – a metric based on Loma Linda University’s Vegetarian Food Guide Pyramid.

Methods: Males and post-menopausal females from the Cancer Prevention Study-II Nutrition Cohort with food frequency questionnaire (FFQ) data, self-reported physical activity (PA), and BMI of 15- < 60 kg/m² in 1999 were analyzed (n=119,885). VLI scores were created from dietary components of adequacy (6 plant food groups, vitamin B12, water), moderation (dairy, eggs, sweets), and exclusion (flesh-foods), plus PA. High VLI scores (range 0-13) indicate alignment with a healthy vegetarian diet and lifestyle. Nutrients of concern for vegetarians and older adults (calcium, potassium, fiber, vitamin D, sodium, protein, vitamin B12, iron) were estimated from FFQs (no supplements) and compared to Estimated Average Requirement, Adequate Intake, and Chronic Disease Risk Reduction standards. Chi-squared tests compared proportions of nutrient inadequacy or excess (sodium) across VLI quintiles by sex and age (≤70y, >70y).

Results: Participants (44% male, 98% White, mean age 70y) had median VLI scores of 5.5 (IQR: 4.5, 6.0). A high percentage of participants in all VLI quintiles had intakes below recommended levels for calcium (61-81%), vitamin D (90-96%), fiber (51-97%), and potassium (males 55-71%; females 30-49%). Fewer had low intakes of protein (20-28%), B12 (2-8%), and iron (1-3%), or excess sodium (15-41%). The proportion of inadequacy for iron, fiber, and potassium, and of excess sodium, decreased stepwise across VLI quintiles (Q1 to Q5), whereas inadequacy for calcium, vitamin D, and B12 increased across quintiles (p < 0.001 for all). Inadequacy for calcium (males ≤70y) and protein was similar across quintiles (p>0.05).

Conclusions: Most participants had intakes of calcium, vitamin D, fiber, and potassium below recommended levels. Those with higher VLI scores were more likely to meet standards for sodium, fiber and potassium (largely from plants), but not calcium or vitamin D (largely from animals). These findings suggest that the VLI captures aspects of diet quality specific to a healthy vegetarian diet.

Funding Sources: American Cancer Society