Associations Between Dietary Patterns, LDL Aggregation, and Cardiometabolic Health: A Cross-sectional Analysis.

To measure changes in how easily LDL cholesterol particles 'clump' together in the blood vessels from baseline to post-intervention, assessed via plasma lipid and lipoprotein analysis.

Changes in plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides will be determined via enzymatic analysis and measured in mmol/L.

Changes in lipoprotein particle size (diameter) will be measured via Nuclear Magnetic Resonance spectroscopy (NMR) and expressed in nanometers.

Participants will complete a semi-structured interview (~30-45 minutes) to explore their experiences of their chosen dietary pattern. Interviews will assess eating behaviour, attitudes, motivation, and perceived impact of the chosen diet. Question subsections include overall experience, practical challenges, social and lifestyle factors, and intentions to continue the diet. Interviews will be conducted in person or online via Microsoft Teams, audio-recorded with consent, transcribed verbatim, and anonymised prior to thematic analysis.

Change in resting systolic and diastolic blood pressure. Blood pressure reflects cardiovascular function and may be influenced by dietary fat type and nutrient composition.

Change in blood vessel function will be assessed using a non-invasive ultrasound test to measure how well the arteries widen (dilate) in response to increased blood flow.

Changes in fasting blood glucose will be assessed via biochemical plasma analysis of a venous blood sample and recorded in mmol/L.

Participants' self-reported adherence to the assigned diet will be collected through completion of a 3-day online food log/diary via a mobile phone application.

Non-invasive ultrasound measurement of how quickly blood pressure waves move through the carotid artery.

CIMT is a non-invasive ultrasound method used to measure the thickness of an artery wall which can give information about blood vessel health.

Height will be measured in metres using a stadiometer.

Changes in body weight will be measured in kilograms using a SECA bioelectrical impedance analyser.

BMI will be calculated calculated by dividing an adult's weight in kilograms by their height in meters squared.

Using a SECA bioelectrical impedance analyser, body fat percentage will be estimated by sending a weak, painless electrical current through the body, measuring the resistance (impedance) encountered.

Waist to hip ratio will be measured using a measuring tape to measure the narrowest point of the waist and the widest point of the hips. The ratio will be calculated by dividing waist circumference by hip circumference (WHR = Waist ÷ Hip) using the same unit of measurement (cm or inches).

Changes in fasting blood insulin levels will be assessed via biochemical plasma analysis of a venous blood sample and recorded in mcU/mL.

HOMA-IR measures insulin resistance using fasting blood glucose and insulin, with a score of > 2.0 or 2.5 typically indicating resistance.

A validated self-report questionnaire assessing physical activity performed during the previous 7 days. Participants report frequency and duration of vigorous activity, moderate activity, walking, and sedentary time. Responses are used to estimate total habitual physical activity (e.g., MET-minutes/week).

An 18-item self-report scale measuring an individual's tendency to engage in and enjoy effortful cognitive activity. Items are rated on a Likert-type scale (1-5; strongly disagree to strongly agree). Scores are summed or averaged, with higher scores indicating greater need for cognition.

A 15-item self-report questionnaire assessing general endorsement of conspiracy beliefs across multiple domains. Items are rated on a 5-point Likert scale (1 = definitely not true to 5 = definitely true). Higher scores indicate stronger conspiracist beliefs.

A self-report measure assessing frequency of digital media and technology use and attitudes toward technology. Items assessing usage are rated on Likert-type frequency scales (e.g., 1 = never to 10 = all the time), while attitude items use agreement Likert scales. Higher scores reflect greater usage or stronger attitudes toward technology.

A self-report questionnaire measuring the extent to which individuals view science as a reliable and authoritative source of knowledge. Items are rated on a 6-point Likert scale (strongly disagree to strongly agree), with higher scores indicating stronger belief in science.

A self-report scale assessing beliefs that human behaviour and events are determined by scientific and physical laws. Items are rated on a Likert-type agreement scale (e.g., 1 = strongly disagree to 7 = strongly agree), with higher scores indicating stronger endorsement of scientific determinism.

A self-report measure assessing the degree to which individuals identify with a specific social group. Items are rated on a Likert-type agreement scale (typically 1-7), measuring aspects such as group belonging, attachment, and identification. Higher scores indicate stronger social identification.