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 (& beta; -0.81, 95% CI -1.0, -0.62; & beta; - .61, 95% CI -0.72, -0.5) and a healthier lipid profile (lower levels of cholesterol & beta; -0.05, 95% CI -0.06, -0.04, triglycerides & beta; -0.05, 95% CI -0.06, -0.03, and higher HDL cholesterol & beta; 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.