Characterising the diversity of plant-based food and beverage consumption in adults, and exploring associations with cardiometabolic health outcomes: A cross-sectional study

Background and aims

A growing body of evidence indicates plant-based food diversity as a potential target for improvement of diet-related health outcomes. This study aimed to characterize the quantity and diversity of plant-based foods consumed in the UK and explore associations between plant-based food diversity and cardiometabolic health outcomes.

Methods

Cross-sectional data from the UK National Diet and Nutrition Survey Rolling Programme Year 9 (2016/2017) was analysed. Plant-based food quantity (g/d) and diversity (number of discrete plant foods consumed; counts/d) from all plant food sub-groups (fruits, vegetables, grains, herbs, spices, nuts, seeds, fats, oils, beverages), and diet quality (Nutrient Rich Foods index) were determined from 4-day food diaries. Demographic and health outcome data (BMI, blood pressure, blood lipids, glycated haemoglobin (HbA1c)) were collected at nurse visits. Daily diversity count was categorised into terciles. Multiple regression models were conducted to identify predictors of plant-based food diversity, and associations between diversity and cardiometabolic health outcomes.

Results

Overall, 677 adults were included. Median quantity and diversity of plant-based food intake were 999.3 g/d (IQR 771.6 g/d) and 8.0 counts/d (IQR 3.8 counts/d), and diversity terciles were low (5.5, IQR 1.8 counts/d), moderate (8.1, IQR 1.3 counts/d), and high (11.0, IQR 2.3 counts/d). Plant-based food diversity was positively correlated with diet quality (Spearman's r = 0.265, p < 0.001). Higher educational attainment, annual income and vegetarian dietary pattern were predictive of higher diversity (adjusted R² = 0.206; p < 0.001). Higher diversity was associated with higher HDL cholesterol (B = 0.029 mmol/L; 95%CI: 0.01, 0.05; p = 0.003), and lower total:HDL ratio (B = −0.07; 95%CI: −0.13, −0.01; p = 0.023) and HbA1c (B = −0.57 mmol/mol; 95%CI: −1.02, −0.13; p = 0.013), however models were no longer significant following adjustment for BMI.

Conclusions

Increasing plant-based food diversity is a potential target for diet quality improvement at population level, with benefits for cardiometabolic health outcomes that warrant further investigation in human trials.