Diet constitutes one of the key modifiable risk factors in the aetiology of CMD^{(Reference Fransen and Ocké1)}. Diet quality scores (DQS) measure adherence to a predefined diet to quantify an individual's food and nutrient intakes^{(Reference Waijers, Feskens and Ocké2)}. Although many scores have been defined and used in epidemiological studies to assess diet quality, there is uncertainty about how a priori defined DQS relate to CMD risk. We investigated the relationship between three widely used DQS and a comprehensive range of CMD risk factors in adults living in and around the Reading area.

In this analysis, baseline data (n = 734) was pooled from four randomised controlled trials and one observational study previously conducted in the Hugh Sinclair Unit of Human Nutrition (DIVAS, DIVAS-2, SAT-gene, RESET, and BODYCON) in adults aged 18–70 y. Habitual dietary intakes were obtained using weighed diet diaries of ≥ 3 days. The dietary data was first categorised using a detailed food definition list to standardise the format of the food intake information between studies. The following DQS were calculated: Healthy Eating Index (HEI)-2015, alternate Mediterranean Diet Score (aMED), and Dietary Approaches to Stop Hypertension (DASH) score, where higher scores represent greater adherence to dietary guidelines/patterns. These scores were identified as commonly used DQS^{(Reference Yilmaz3)}. Data were first stratified into quartiles (Q) of increasing DQS before analysis using an ANCOVA, with age, sex, supplement use, CVD risk and energy intake as covariates. CMD risk factors -anthropometric measures, blood pressure (BP), fasting blood lipids, blood glucose and insulin- were measured.

The mean age of the participants was 44 (SD 14) y, 42% were male, and two of the studies had recruited participants with a moderate CVD risk (1.5-fold higher than the general population based on the Framingham risk score) which comprised 41% of the cohort. For all DQS, higher scores were associated with lower anthropometric measures (body mass index, waist circumference, body fat percentage and waist-to-height ratio) (Q4 vs Q1, p trends <0.001). In addition, those in Q4 (vs Q1) had lower diastolic BP, homeostatic model assessment for insulin resistance, fasting insulin and TAG, and higher high-density lipoprotein cholesterol (P trends <0.01). Compared to Q1, those in Q4 of the DASH score had lower total cholesterol (TC), while aMED was the only score not associated with low-density lipoprotein cholesterol (LDL-C) concentration. No relationships were observed between the DQS and systolic BP or fasting glucose concentration.

The study found that higher scores of HEI-2015, aMED, and DASH were associated with more favourable cardio-metabolic health outcomes in adults. Adhering to these diets may help prevent and/or delay the onset of CMD. Furthermore, better adherence to the DASH diet was associated with positive effects on TC levels, but randomised controlled trials are needed to confirm these observations.