Head and neck cancer patients under (chemo-)radiotherapy undergoing nutritional intervention: Results from the prospective randomized HEADNUT-trial

•Nutritional status impacts outcome of patients with head and neck cancer after (chemo-)radiotherapy.•Parameters from bioelectric impedance analysis may serve as indicators for overall survival.•So-called phase angle and fat-free mass index from bioelectric impedance analysis may predict overall survival in head and neck cancer patients after (chemo-)radiotherapy.•Albumin at the end of (chemo-)radiotherapy predicts overall survival in head and neck cancer patients after (chemo-)radiotherapy. Patients with squamous cell carcinoma of the head and neck undergoing (chemo-)radiotherapy are at high risk of malnutrition. Nevertheless, there is still a lack of prospective, randomized trials investigating the influence of nutritional status on therapy-related toxicity and patients’ outcome. Between October 2018 and October 2020, 61 patients were randomized into an intervention and control group. Questionnaires (MUST, NRS-2002, and Nutriscore), clinical examinations, laboratory analyses, and bioelectrical impedance analysis (BIA) were used to assess nutritional status for all patients at the beginning and end of therapy as well as every 2 weeks during therapy. The intervention consisted of an individualized nutritional counseling every 2 weeks during therapy. Median baseline BMI for all participants was 23.8 (14.5–37.2) kg/m2 and dropped to 22.9 (16.8–33) kg/m2 after therapy (p