Background A deficient nutritional status may be a determining factor in patients with Huntington's disease (HD), leading to increased comorbidity, social and health costs. Our aims will be to analyse the dietary intake of patients with HD, and to determine the association of HD severity in terms of motor, cognitive, psychiatric symptoms, and comorbidity with poor nutritional status.

Methods Observational, cross-sectional, and national multicentre study. This will include the Spanish group of patients diagnosed HD-CAG mutation included in the European HD REGISTRY. The dietary intake will be evaluated using structured validated questionnaires, administered by telephone and post. These questionnaires will collect the frequency of food consuming, and the intake of nutrients at an individual and population level. Data in terms of sociodemographic characteristics, duration of disease, anthropometric variables such as the body mass index [BMI], CAG repeats, disease severity (Unified Huntington's Disease Rating Scale [UHDRS], costs, treatments, quality of life and care giver burden, will be collected from the Euro-HD REGISTRY data. A descriptive analysis will be performed to characterise this population. Comparative and regression analysis will be performed to analyse the nutritional variable differences among subjects with HD, and the association of nutritional variables and dietary intake with HD severity in these patients, adjusting for confounding variables, respectively.

Relevance The determination of the consumption and nutritional status of HD and their association with HD severity, could help to introduce appropriate dietary measures, to prevent complications, and to improve the patients'quality of life, and care giver burden.