Head and neck cancer (HNC) is associated with a high risk of malnutrition. Malnutrition is defined as acute weight loss greater than 5% and increases mortality 1.7-fold for HNC patients. The aim of the study was to investigate the social and nutritional impairments that patients face throughout cancer-survivorship. The study was conducted nationwide via the self-help network and in a single oncological center. We analysed 134 patient reported outcome (PRO) questionnaires with a mean age of 65.5±9.4 years, including 88 males, 36 females, and ten participants of undisclosed sex. The questionnaire contained 47 items enquiring about demography, weight development, and how treatment impaired nutrition. The patient data showed a weight loss of 8% after surgery, 13% after (chemo)radiotherapy [(C)RT] and a return to baseline weight in convalescence. However, patients with a baseline weight >100 kilogram (kg), had a 22% weight loss after (C)RT (p<0.0001) and this remained permanent at 11% (p=0.0041). Treatment-associated side-effects gradually decreased in the course compared to the time of treatment: loss of taste (55% to 21%), xerostomia (56% to 42%), dysphagia (57% to 43%), and dental problems (33%/ to 21%). (C)RT immediately led to more loss of taste (p=0.0461) and dysphagia (p=0.0334), and surgery as a singular modality scored the lowest odds ratio for side-effects. Social Impact: mood, supporting networks, and supplement satisfaction were rated "good" (Likert Scale). Malnutrition is common among HNC patients. High baseline weight and extensive multimodal treatment are important risk factors that require enhanced stewardship.