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.