Excessive intake of protein – Effects & Side effects

excessive intake of protein

Protein is an essential component of the human diet, However, excessive intake of protein should be avoided especially in patients with kidney & liver diseases.

Meat is a very rich source of proteins, iron, zinc, and vitamin B12. Compared to iron derived from plant sources, iron derived from animal proteins is readily absorbed.

Apart from being an essential component of the human diet, excessive intake of protein may also have some potential hazards. The most worrisome of these is its association with adverse cardiovascular diseases and colorectal carcinoma.

Why is the intake of meat / Proteins important?

Most of the evolutionists consider the human teeth as indirect evidence that humans have evolved as omnivores. This is further evidenced by the fact that some essential vitamins for the human body can only be obtained from animal proteins.

What diseases may be encountered in patients not taking proteins?

  1. Protein-energy malnutrition
  2. Iron deficiency
  3. Vitamin B12 deficiency
importance of meat intake
protein energy malnutrition

Protein-energy malnutrition:

Most of the children and adolescents of developing countries and under-developed countries suffer from protein-energy malnutrition. This is termed as kwashiorkor.

Children have wasting of the muscles, enlarged liver with fatty deposition, leg and periorbital swelling, abdominal distension due to fluid in the abdominal cavity, anemia, anorexia, itchy rash, and heart failure. Treatment is with high protein diets.

Iron deficiency:

Individuals with iron deficiency may feel tired, anorexic and have craving for non-food items. They may also develop anemia and notice pallor, have palpitation, headache and develop shortness of breath on exertion. Treatment is with iron supplementation and intake of foods rich in iron.

Vitamin B12 deficiency:

Vitamin B12 is an essential component of nerve sheaths and is also required for red blood cell synthesis. Individuals who have a deficiency of vitamin B12 may develop numbness, paraesthesias and burning sensation in the feet.

They may also have memory problems and develop anemia and mild jaundice. Vitamin B12 is the only vitamin derived exclusively from animal proteins. Strict vegetarians are therefore at risk of developing vitamin B12 deficiency.

Treatment is with replacing vitamin B12 and the intake of foods rich in vitamin B12.

Can a person be deficient in proteins despite taking meat?

Yes. Sometimes individuals take a sufficient amount of dietary proteins but they are still deficient in proteins and albumin. These patients may have a defect in absorption like those with diarrheal diseases.

Patients might also lose proteins through the kidneys as in nephrotic syndrome and diabetic nephropathy. Individuals may have a defective synthesis of proteins from amino acids. This group of patients includes those with liver disease.

What may be the potential hazards of excessive intake of meat?

Cardiovascular diseases:

Meat intake, especially in large amounts, have long been associated with Cardiovascular diseases including coronary artery diseases and myocardial infarction. Recent studies have not found any such associations.

The presence of a fatty component in meat is what probably matters. Lean meat has been shown to be beneficial if taken in moderate amount (20 to 80 grams per day or up to 500 grams per week)

meat excess
colon cancer

Colorectal cancer

The second association with the intake of meat is the increased incidence of colorectal carcinoma. Again the evidence in favor of this association is very weak. Researchers have concluded that multiple factors play roles in the development of colorectal cancer.

These include genetics, age, amount and the type of meat consumed and how it is cooked. Processed meat and smoked meat has especially been associated with the incidence of colorectal cancer.

Which patients need to be cautious when taking meat?

Excessive intake of protein should be avoided by the following group of patients.

Patients with renal disease:

Kidney disease patients should limit protein intake to 0.8 to 1 gram per kg per day. Since proteins are converted into nitrogenous wastes and the kidneys cannot clear those wastes, dietary intake of proteins should be restricted. These include animal proteins like meat, eggs, and milk as well as plant proteins comprising mostly of pulses.

Patients with liver disease:

Liver disease patients cannot detoxify ammonia which is a major product of proteins degradation. Intake of an excess amount of proteins causes ammonia in the blood to rise. Ammonia crosses the brain cells and leads to a change in mentation and coma. This is called hepatic encephalopathy and is an emergency condition.

excessive intake of proteins
flare-up of gout


Patients who have joint pains due to high uric acid levels in the body can have a flare of their illness if protein intake in their diet increases. Because purines in meat are converted into uric acid which may deposit in the joints and kidneys. Thus flaring up a quiescent joint or kidney disease.

Eid-u-Adha – the festival of sacrifice

Message for this Eid-ul-Adha

  1. Eat meat in moderate amounts not exceeding 100 grams per day especially those individuals with preexisting cardiovascular diseases, renal disease, and hepatic disease.
  2. Try to take salads and green tea especially during Eid to maintain a little balance.
  3. Distribute the meat among the poor and needy people as advised by our Holy Prophet to divide the meat into three parts – one part for the needy and poor, one part for your relatives and one part for your own self.
  4. Do not eat full stomach
  5. Avoid smoked and burnt meat.


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