INTRODUCTION: Reliable dietary information is crucial for measuring the habitual diet of healthy participants and patients with dyslipidaemia and/or coronary heart disease (CHD). Even so, methods are often complicated and time-consuming for everyone involved. We aimed to validate the new food frequency questionnaire (FFQ) named HeartDiet by comparing it to a validated 198-item FFQ and biomarkers.

METHODS: Healthy local participants (n = 100) and participants with CHD from Aalborg University Hospital (n = 100) randomly completed HeartDiet and the 198-item FFQ. Biomarkers were analysed in a random sample of 50 healthy participants. Scatter plots and Spearman's rank correlation coefficient were used for statistics.

RESULTS: We found a highly significant statistical correla-tion between the intake of fruit (ρ = 0.70; 95% confidence interval (CI): 0.62-0.76), vegetables (ρ = 0.54; 95% CI: 0.44-0.64), fish (ρ = 0.75; 95% CI: 0.68-0.81) and saturated fatty acids (ρ = -0.51; 95% CI:-0.61--0.40) measured by the HeartDiet and the 198-item FFQ. Also, correlations between the HeartDiet and serum β-carotene and serum n-3 polyunsaturated fatty acids were statistically significant (fruit and vegetables: ρ = 0.59; 95% CI: 0.37-0.74, and fish: ρ = 0.45; 95% CI: 0.19-0.65).

CONCLUSIONS: HeartDiet is well aligned with results from a semi-quantitative FFQ and biomarkers, and it is a practical, easy and quick-to-use tool to describe and monitor if a diet is heart-healthy or not.

FUNDING: The study was supported by the Danish Heart Association.

TRIAL REGISTRATION: not relevant.