Nutrition and Exercise Prehabilitation in Patients Awaiting Liver Transplantation

Changes in Global Leadership Initiative on Malnutrition (GLIM)-defined malnutrition

Malnutrition will be diagnosed using the Global Leadership Initiative on Malnutrition (GLIM) criteria. Diagnosis requires at least 1 phenotypic criterion and 1 etiologic criterion. Phenotypic criteria include: a. Non-votional weight loss (%): \> 5% within past 6 months or \> 10% beyond 6 months, b. Low body mass index (BMI, kg/m\^2): \< 20 kg/m\^2 if \< 70 years or \< 22 kg/m\^2 if \> 70 years, c. Reduced muscle mass, assessed by validated body composition measuring techniques \[e.g. Dual-Energy X-ray Absorptiometry (DEXA), Bioelectrical Impedance Analysis (BIA) or Computed Tomography (CT)\]. Etiologic criteria include: a. Reduced food intake or assimillation: ≤ 50% of energy requirements \> 1 week or any reduction for \> 2 weeks or any chronic gastrointestinal condition that adversely impacts food assimilation or absorption, b. Inflammation: acute disease/injury or chronic disease-related.

Changes in Computed Tomography (CT)-derived muscle mass

Muscle mass will be assessed using the Skeletal Muscle Index (SMI, cm\^2/m\^2). SMI will be calculated by measuring the total cross-sectional area of skeletal muscles, from a single cross-sectional Computed Tomography (CT) image at L3 vertebral level, using Hounsfield Units of -29 to +150 HU, and normalizing to height squared (m\^2).Thresholds for reduced SMI will be considered \< 50 cm\^2/m\^2 for men and \< 39 cm\^2/m\^2 for women.

Changes in handgrip strength (kg)

Handgrip strength (kg) will be assessed using a digital handgrip dynamometer. Thresholds for reduced muscle strength will be considered \< 27 kg for men and \< 16 kg for women.

Changes in Short Physical Performance Battery (SPPB) score

The Short Physical Performance Battery (SPPB) includes 3 components: 3-positions balance testing (sec) (0-4 points), 4-meter gait speed test (sec) (0-4 points) and 5-times chair stand test (sec) (0-4 points), with a total score of 0-12. Higher scores indicate a better physical performance: 0-3 points for worst physical performance, 4-9 points for reduced physical performance and 10-12 points for best physical performance.

Nutritional Risk Screening-2002 (NRS-2002)-derived nutritional risk

Nutritional risk will be assessed using the Nutritional Risk Screening-2002 (NRS-2002) tool. Higher scores indicate greater nutritional risk: \< 3 points indicate good nutritional status and ≥ 3 nutritional risk.

Malnutrition Screening Tool (MST)-derived nutritional risk

Nutritional risk will be assessed using the Malnutrition Screening Tool (MST) tool. Higher scores indicate greater nutritional risk: \< 2 points indicate good nutritional status and ≥ 2 nutritional risk.

Malnutrition Universal Screening Tool (MUST)-derived nutritional risk

Nutritional risk will be assessed using the Malnutrition Universal Screening Tool (MUST) tool. Higher scores indicate greater nutritional risk: 0 points indicate low risk, 1 point medium risk and ≥ 2 high risk.

Short Nutritional Assessment Questionnaire (SNAQ)-derived nutritional risk

Nutritional risk will be assessed using the Short Nutritional Assessment Questionnaire (SNAQ) tool. Higher scores indicate greater nutritional risk: 0-1 points indicate low risk, 2 points medium risk and ≥ 3 points high risk.

Adherence to the program

Adherence to the program will be assessed using 24-hour recalls and physical activity diaries.

Satisfaction with the program

Satisfaction with the program will be assessed using a Likert scale: very satisfied, fairly satisfied, neither satisfied nor dissatisfied, slightly dissatisfied and not at all satisfied

Global Leadership Initiative on Malnutrition (GLIM)-defined malnutrition

Malnutrition will be diagnosed using the Global Leadership Initiative on Malnutrition (GLIM) criteria. Diagnosis requires at least 1 phenotypic criterion and 1 etiologic criterion. Phenotypic criteria: a. Non-votional weight loss (%): \> 5% within past 6 months or \>10% beyond 6 months b. Low body mass index (BMI, kg/m\^2): \< 20 kg/m\^2 if \< 70 years or \< 22 kg/m\^2 if \> 70 years c. Reduced muscle mass, assesses by validated body composition measuring techniques \[e.g. Dual-Energy X-ray Absorptiometry (DEXA), Bioelectrical Impedance Analysis (BIA) or Computed Tomography (CT) Etiologic criteria: a. Reduced food intake or assimillation: ≤ 50% of energy requirements \> 1 week or any reduction for \> 2 weeks or any chronic gastrointestinal condition that adversely impacts food assimilation or absorption b. Inflammation: acute disease/injury or chronic disease-related

Computed Tomography (CT)-derived muscle mass

Muscle mass will be assessed using the Skeletal Muscle Index (SMI, cm\^2/m\^2). SMI will be calculated by measuring the total cross-sectional area of skeletal muscles, from a single cross-sectional Computed Tomography (CT) image at L3 vertebral level, using Hounsfield Units of -29 to +150 HU, and normalizing to height squared (m\^2).Thresholds for reduced SMI will be considered \< 50 cm\^2/m\^2 for men and \< 39 cm\^2/m\^2 for women.