A Mediterranean dietary pattern intervention does not improve cardiometabolic risk but does improve quality of life and body composition in an Aotearoa New Zealand population at increased cardiometabolic risk: A randomised controlled trial

Aims: To test if a New Zealand food-based Mediterranean diet (NZMedDiet) with behavioural intervention improves cardiometabolic health and wellbeing.

Methods: A randomised controlled trial comparing 12 weeks of the NZMedDiet to usual diet in participants with increased cardiometabolic risk (metabolic syndrome severity score [MetSSS] > 0.35). The intervention group was provided with food and recipes to meet 75% of their energy requirements, supported by a behavioural intervention to improve adherence. The primary outcome measure was (MetSSS) after 12 weeks.

Results: Two hundred individuals with mean (SD) age 49.9 (10.9) years of which 62% women were enrolled with their household/whānau. After 12 weeks, the mean (SD) MetSSS was 1.0 (0.7) in the control (n = 98) and 0.8 (0.5) in the intervention (n = 102) group; estimated difference (95% confidence interval [CI]) of -0.05 (-0.16 to 0.06), p = 0.35. The Mediterranean diet score (PyrMDS) was greater in the intervention group 1.6 (1.1-2.1), p < 0.001, consistent with a change to a more Mediterranean dietary pattern. Weight reduced in the NZMedDiet group compared with control (-1.9 kg [-2.0 to -0.34]), p = 0.006 and wellbeing, assessed by the SF-36 quality of life questionnaire, and improved across all domains. For example, the physical component summary score difference (95% CI) was 4.0 (2.4-5.7), p < 0.001, and the mental component summary score difference was 3.0 (0.7-5.2), p = 0.01.

Conclusion: In participants with increased cardiometabolic risk, food provision with a Mediterranean dietary pattern and a behavioural intervention did not improve metabolic risk scores but was associated with reduced weight and improved quality of life.