The primary endpoint is weight changes up to one year from admission to the hospital. Secondary endpoints include forced expiratory volume in one second (FEV1), forced vital capacity (FVC), six-minute walk distance, hand-grip strength, health related quality of life (HRQoL), length of hospital stay, nutritional status, energy- and protein intake, readmissions to the hospital in within 30 days, as well as the total number of readmissions to the hospital and acute exacerbation during follow-up. Functional outcome measurements will be conducted by trained research assistant in collaboration with the PhD student. Information about background diets, HRQoL as well as compliance to the intervention diets will be gathered by the PhD and MS students.