Fig. 1.

Nitrate Knowledge Index scores in different sociodemographic groups. Analyses were stratified by age (panel A; younger (< 40 years) v. older (≥ 40 years)), gender (panel B; male v. female), ethnicity (panel C; white v. other), education level (panel D; lower (GCSE, A Level, vocational, other) v. higher (undergraduate degree, Master’s degree or PhD)), employment status (panel E; employed and self-employed v. other), household income (panel F; lower (<£35 700) v. higher (≥£35 700)), BMI (panel G; <25 kg/m² v. ≥25 kg/m²), exercise level (panel H; lower (do not exercise) v. higher (other)), level of nutrition education (panel I; lower (no nutrition education, unsure and other) v. higher (secondary school level of nutrition education and above)), and prior knowledge of nitrate (panel J; had not heard of nitrate v. heard of nitrate). Data presented are median (IQR). * = significant difference (P < 0·05) between groups. Individuals who were employed, with higher nutrition education, and who had heard of nitrate prior to completing the questionnaire showed significantly greater knowledge of dietary nitrate IQR, interquartile range.