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.