Trial Outcomes & Findings for The Efficacy of Individualized Dietary Advice in Improving Diet Quality and Cardiovascular Health (NCT NCT03854461)

Recruitment took place between December 2021 and November 2022 at both Queen's University Belfast, Northern Ireland and University College Dublin, Republic of Ireland sites.

As n=12 participants who were enrolled onto the study were not contactable afterwards to arrange baseline (Month 0) study visits, n=162 participants in total were enrolled to account for losses identified early in data collection process before baseline visit. N=150 completed baseline (Month 0) visits but n=1 participant was discovered to be ineligible at baseline visit and was removed. Therefore n=149 completed baseline visits and were randomised.

Race and Ethnicity were not collected from any participant.

Dietary quality will be assessed using an online version of the Prime Diet Quality Score (PDQS). Foods are classified as healthy and unhealthy. Points are assigned according to the following criteria: 0-1 serving/wk (0 point) compared with 2-3 servings/wk (1 point) compared with ≥4 servings/wk (2 points) for the healthy food groups. Scoring is reversed and points deducted for the unhealthy food groups. Points for each food group are summed to give an overall score. The PDQS has 21 food groups and ranges from 0 to 42 total score (scores on a scale), with a higher score indicating a better diet quality.

Questionnaire to assess number of units consumed weekly

Questionnaire to assess usual medication use (drug name, dose and frequency of use)

Physical activity using an accelerometer; data to be used will be total step count

Weight will be measured in kg using calibrated scales.

Waist and hip circumference will be measured in cm according to standardised operating procedures using a tape measure.

Height will be measured in metres using a stadiometer.

Body composition (% body fat) will be measured using bioelectrical impedence (Bodystat 1500).

Blood pressure will be measured twice from the right arm, using an automated Omron sphygmomanometer, with the participant sitting quietly for at least five minutes.

Serum lipids (total cholesterol, HDL-C, and TG) and whole blood HbA1c will be assessed by enzymatic assays (Randox Ltd, Crumlin, NI and Glen Bio, Antrim, NI) on an I-Lab 600 auto-analyzer. LDL-C will be calculated.

The following biomarkers will be used to assess nutritional status response to the dietary intervention: red meat - methylhistidines and carnosine; white meat - TMAO, guanidoacetate, anserine; fruit and vegetables -- proline betaine, isothiocyanates, S-methyl-L-cysteine sulfoxide, and tartaric acid; wholegrains - alkylresorcinols; coffee - phenolic acids, N-methylpyridinium, trigonelline, 2-furoylglycine; SSBs -- formate, citrulline, taurine, and isocitrate) red meat- methylhistidines; oily fish- omega-3 index; fruit and vegetables- total carotenoids and proline betaine; wholegrain- alkylresorcinols.

Sample handling and nucleic acid purifications will be performed following an established protocol. Illumina DNA-seq libraries with fragment length of \~300 bp will be generated as previously described, with Pippen prep size selection. For RNA-seq, 5ug of RNA will be enriched for mRNA and subjected to strand-specific cDNA synthesis using established protocols. Paired-end sequencing (e.g. 150x150 nt) will be performed on the Illumina HiSeq platform.