Comparative Effects of Carnivore and Mediterranean-style Diets on LDL Aggregation and Cardiometabolic Health

The goal of this clinical trial is to learn whether following a Mediterranean-style diet or a Carnivore-style diet can improve heart and metabolic health in men and women aged 30-60 years with high LDL cholesterol. The main questions it aims to answer are: 1. Does following a Mediterranean or Carnivore diet change how easily LDL cholesterol particles clump together (LDL aggregation susceptibility)? 2. Do these two diets have different effects on other measures of heart and metabolic health, such as blood fats, blood vessel function, and overall wellbeing? Researchers will compare people who follow the Mediterranean-style diet with those who follow the Carnivore-style diet to see which diet produces more beneficial changes in cholesterol and heart health markers. Participants will: * Attend three visits at Liverpool John Moores University for screening and data collection. * Be randomly assigned to follow either the Mediterranean or Carnivore diet for 3 weeks, matched for calories and protein. * Provide fasting blood, urine, and stool samples before and after the diet period. * Complete non-invasive cardiovascular tests to measure blood vessel and heart function. * Take part in a short interview and complete questionnaires about their experience of following the diet.