Excess protein, hyper-ammonemia and liver damage risk

The amino acids from the protein in the foods that we eat are metabolised by liver cells so they can be used by the body. As a result, a by-product and toxic substance called ammonia is produced as well.

Since the ammonia produced by hepatic protein metabolism is quite toxic, it also needs to be neutralised by the liver and converted into urea. Urea is much less toxic than ammonia and is excreted by the kidneys as urine.

However, eating excessive amounts of protein can result in an increased amount of ammonia in the blood (hyper-ammonemia), which can in turn overload the liver and lead to liver damage.

On the other hand, too little protein can reduce healing of the liver. So being able to calculate and personalise protein intake amounts for different clients and athletes is key.

For example, what is an excessive protein intake for a sedentary person could be insufficient protein intake for an Olympic swimmer! We show you how to personalise and calculate the protein amounts for different athletes and regular exercisers inside the Advanced Sports and Exercise Nutritional Advisor certification. You can download the full PDF curriculum here.

References and further reading materials for you:

• Hyperalbuminemia and elevated transaminases associated with high-protein diet.
• Long-term intake of a high-protein diet increases liver triacylglycerol deposition pathways and hepatic signs of injury in rats.
• Liver disease and protein needs.
• A review of issues of dietary protein intake in humans.
• Liver Diseases.
• How does the liver work?
• Nutrition and Liver Health.
• ESPEN guideline on clinical nutrition in liver disease.

AUTHOR: Alex Ruani, Research Director

Updated on: 14/10/2026