Assessing Performance of Contemporary Plant-Based Diets against the UK Dietary Guidelines: Findings from the Feeding the Future (FEED) Study

Abstract

Uncertainty remains about the composition of contemporary plant-based diets and whether they provide recommended nutrient intakes. We established Feeding the Future (FEED), an up-to-date online cohort of UK adults following different plant-based diets and diets containing meat and fish. We recruited 6342 participants aged 18-99 [omnivores (1562), flexitarians (1349), pescatarians (568), vegetarians (1292), and vegans (1571)] between February 2022 and December 2023, and measured diet using a food frequency questionnaire and free text. We compared personal characteristics and dietary intakes between diet groups and assessed compliance with dietary guidelines. Most participants met UK dietary recommendations for fruit and vegetables, sodium, and protein, although protein intakes were lowest among vegetarians and vegans. Omnivores did not meet the fibre recommendation and only vegans met the saturated fat recommendation. All diet groups exceeded the free sugars recommendation. Higher proportions of vegetarians and vegans were below the estimated average requirements (EARs) for zinc, iodine, selenium, and, in vegans, vitamins A and B12, whereas calcium intakes were similar across the diet groups. People following plant-based diets showed good compliance with most dietary targets, and their risk for inadequate intakes of certain nutrients might be mitigated by improved dietary choices and/or food fortification.

Keywords: cohort; diet; dietary guidelines; flexitarians; nutrients; plant-based; vegans; vegetarians.

Figure 1

Mean body mass index (BMI) by age and diet group. Exclusions: 304 participants with missing values for height and weight, 100 participants who preferred not to state their gender.

Figure 2

Daily dietary intakes in relation to UK dietary guidelines. Diet groups: O = omnivores, F = flexitarians, P = pescatarians, V = vegetarians, Ve = vegans; Black squares represent mean daily intakes and black lines represent standard errors; Reference lines represent the UK dietary recommendations for adults and reference nutrient intake (RNI) values for protein (green line = min, orange line = max).

Figure 3

Daily micronutrient intakes in relation to UK Reference Nutrient Intakes (RNIs). Diet groups: O = omnivores, F = flexitarians, P = pescatarians, V = vegetarians, Ve = vegans; black squares represent mean daily intakes and black lines represent standard errors; intakes of vitamin A, iron, selenium, and zinc are presented separately by women (grey circles, grey standard error lines) and men (black squares, black standard error lines); reference lines represent the UK RNI for adults (green line) and sex-specific RNI targets for women (pink line) and men (blue line).