The intervention follows a parallel double-blind randomised control design. The intervention duration is 12 weeks, with a mid-point assessment at 6 weeks. Randomisation to groups; rapeseed oil, sunflower oil or habitual diet is performed using a block stratified allocation based on age (under or over 45) and BMI (under or over 30kg/m2) and is carried out remotely via phone.
Participants allocated to either oil groups are instructed to consume the oils uncooked, as a partial replacement to their habitual fat intake. Participants in the control group are asked to not change any aspect of their diet.
Spot urine samples are collected from all participants at all time points for measurement of the primary outcome (proteomic biomarker score). Urine is collected in a plastic tube, mid-flow, as the second urination of the day at baseline, 6 and 12 weeks.
Fasting venous blood is collected for the assessment of secondary outcomes, at baseline, 6 weeks and 12 weeks. Participants are also asked to complete a 2-day food diary at weeks 0, 6 and 12