Development of a measure of dietary quality for the UK Biobank

BACKGROUND: Previous studies of the UK Biobank have examined intake of single food items and their association with health outcomes. Our aim was to develop a dietary quality score and examine the relationship between this score and markers of cardiometabolic health. METHODS: Principal component analysis was performed on dietary data from UK Biobank participants. Linear regression was used to analyse the relationship between diet and cardiometabolic health. RESULTS: The first component explained 14% of the variation in the dietary data. It was characterised by high consumption of meat and low fibre carbohydrates, and a low intake of fruit and vegetables. A higher score, indicative of healthier diet, was associated with lower systolic and diastolic blood pressure (β −0.81, 95% CI −1.0, −0.62; β − .61, 95% CI −0.72, −0.5) and a healthier lipid profile (lower levels of cholesterol β −0.05, 95% CI −0.06, −0.04, triglycerides β −0.05, 95% CI −0.06, −0.03, and higher HDL cholesterol β 0.01, 95% CI 0, 0.01). CONCLUSIONS: The dietary quality score was a good approximation of overall dietary quality. An unhealthy diet was associated with markers of poorer cardiometabolic health.