Definition

Liver transplantation restores liver function. Key aspects to consider in the diet before and after transplantation are outlined here.

Impact on Nutritional Status

Several studies have demonstrated increased mortality after liver transplantation in patients with sarcopenia, malnutrition, hypermetabolism, and obesity ^1,2. Malnutrition is particularly common in patients with liver cirrhosis. Screening using a validated tool, such as the Nutritional Risk Score 2002 (NRS 2002) or Subjective Global Assessment (SGA), followed by a detailed assessment, is essential to identify and address malnutrition prior to transplantation. Preoperative patients should be managed following the ERAS (Enhanced Recovery After Surgery) protocol to minimize fasting periods ³.

Nutrient requirements of patients undergoing surgery or liver transplantation. Adjustments are necessary for malnourished patients, physical activity and age of the patient. The weight used is the adjusted body weight (ADJ) from BMI 28, otherwise the body weight before admission to hospital.   
KG = body weight; d = day. 

Aims of Nutritional Therapy

• Maintenance or improvement of nutritional status
• Prevention of malnutrition or nutrient deficiencies
• Early nutrition (within 12-24 hours) after liver transplantation
• Postoperative nutritional rehabilitation with restoration of total body protein and muscle function

Energy and protein requirements should be covered by oral nutrition whenever possible. If less than 75% of the requirement is met through dietary enrichment, snacks, or sip feeds, enteral nutrition should be introduced as a supplement no later than five days. Complementary parenteral nutrition should be initiated if less than 75% of the requirement is covered by enteral and/or oral nutrition. For detailed guidance, refer to the chapter on enteral and parenteral nutrition.

Preoperative Nutrition

Protein intake should not be reduced in the preoperative period, as intake below 0.8 g/kg body weight per day increases waiting list mortality ⁴.

Sib feeds, micronutrient supplementation, enteral or parenteral nutrition can improve the preoperative nutritional status of patients ^8,9. Probiotic administration can reduce infection rates and accelerate the normalization of ALT, AST, and bilirubin after surgery ¹⁰. Evidence for supplementation of branched-chain amino acids (BCAAs) is insufficient ⁷.

Postoperative Nutrition

After transplantation, patients should receive normal food or enteral nutrition within the first 12 to 24 hours if oral nutrition is insufficient. A reduced energy intake of <18 kcal/kg body weight in the first 48 hours post-surgery may be beneficial ⁵. If oral nutrition is contraindicated, enteral nutrition is used.

Early enteral nutrition (via nasogastric or nasojejunal tube) is generally well-tolerated and can reduce complication rates and healthcare costs. A BCAA-enriched nutrient solution can be beneficial for patients with encephalopathy ⁴.

Parenteral nutrition should only be used in patients for whom enteral nutrition is contraindicated, such as in cases of absent cough and swallowing reflexes or unprotected airways. Standard parenteral nutrition solutions are typically sufficient. Immune-enhancing nutrient solutions have not demonstrated superiority in reducing mortality or morbidity compared to standard solutions ^8,9. MCT/LCT emulsions with reduced ω-6 unsaturated fatty acids may improve reticuloendothelial system function during parenteral nutrition ^4,5.

Practical Tips (if indicated)

• Nutrition can counteract possible side effects of steroid therapy.
• Adequate protein intake to maintain muscle function and increased calcium intake to maintain bone density:
  • Consume a protein supplement with every main meal, including animal-based (e.g., meat, fish, poultry, eggs, dairy products) and plant-based (e.g., tofu, legumes) protein sources; adjust protein intake to individual needs.
  • Protein-enriched milk shakes or yogurt as needed.
  • At least three portions of milk, dairy products, or calcium-rich alternatives to cow's milk.
  • Vitamin D intake is recommended alongside calcium intake.
• Prevention of metabolic diseases such as diabetes: consume sugar-free or low-sugar drinks.
• To avoid a diabetic metabolic state, prefer sugar-free or low-sugar drinks and avoid fruit juices, smoothies, and sweetened beverages.
• Prevent fat deposits in the body and elevated blood lipid levels by monitoring fat intake (food choice and preparation).
• Avoid weight gain with an isocaloric, balanced, and varied diet, and prevent hunger attacks with regular meals. Note: Weight gain is desirable in cases of severe malnutrition and sarcopenia.

Monitoring

• Glucose metabolism: Monitoring is indicated due to frequent disturbances associated with insulin resistance or steroid therapy as part of immunosuppression in the early postoperative period. Hyperglycemia can be prevented or reduced by decreasing glucose intake ⁴.

Special Considerations

• Immediately following liver transplantation, patients experience a loss of approximately 1 kg of total body protein, primarily from skeletal muscle. This deficit often persists even 12 months post-surgery and impacts respiratory muscle function. Rapid rehabilitation of muscle function and total body protein should be prioritized ⁴. Regular physical activity, tailored to the patient’s current fitness level, is recommended to support recovery.
• After liver transplantation, there is an increased risk of sarcopenic obesity and the development of metabolic syndrome, along with heightened long-term cardiovascular morbidity ¹¹. Adherence to a structured exercise and nutrition protocol can help mitigate these risks ⁴.

Medications/Supplements

• Avoid food interactions with immunosuppressants (e.g., grapefruit, pomegranate, pomelo, star fruit, St. John's wort).
• Vitamin A and vitamin D
• Zinc
• Probiotics (after consulting a physician)