Health-Related Quality of Life during 26-Week Intervention with the New Nordic Renal Diet

The New Nordic Renal Diet (NNRD) is a whole-food approach, tailored to meet recommended guidelines in patients with moderate chronic kidney disease (stage 3b-4). The NNRD improved various metabolic and physiological endpoints during a 26-week randomized controlled study. Here, we examined the effect of dietary intervention on health-related quality of life (HRQoL). Sixty participants were recruited (NNRD group n = 30, control group n = 30) and 58 completed the study. During the intervention, the NNRD group received food boxes, and recipes once a week. The control group continued their habitual diet. HRQoL was examined at baseline and at the end of the intervention using the validated EuroQol-5D-5L, including a 5-point scale Likert questionnaire at the end of the intervention. Assessed by the EuroQol-5D-5L questionnaire, the NNRD group experienced a reduction in pain/discomfort during the intervention by 26% [-0.44 points (95% CI; -0.73, -0.16)], compared with no change in the control group [0.25 points (95% CI; -0.02, 0.53)] and a between-group difference of -0.70 points (95% CI; -1.03, -0.37, p < 0.001). A larger decrease of body fat mass was associated with a larger decrease in pain/discomfort (p = 0.014). In addition, the NNRD group reported an overall improvement in conducting usual daily activities by 23% [-0.30-point (95% CI; -0.50, -0.11)], while no change was seen in the control group [-0.02 points (95% CI; -0.21, 0.17)], with a between-group difference -0.28 points (95% CI; -0.51, -0.06, p = 0.014). A larger decrease in 24 h urine phosphorus excretion, used as a marker of compliance, was associated with a larger improvement in conducting usual daily activities (p = 0.036). The NNRD group had a clinically relevant improvement in various HRQoL outcomes.