High-protein diet isn't always better: Here's when it turns risky

While protein is vital for muscle and metabolism, excessive intake, especially from red and processed meats, may put your kidneys, heart, and even cancer risk on the line, experts caution.

Protein has long been hailed as a key nutrient for strength and fitness. But health experts warn that consuming it in excess, especially from animal sources, could do more harm than good. High-protein diets, popular among fitness enthusiasts, may be silently stressing the kidneys, straining the heart, and increasing cancer risks if not balanced carefully.

 

Dr Tushar Tayal, Associate Director, Internal Medicine at CK Birla Hospital, Gurugram, explains, “High protein intakes, especially from foods containing large amounts of red and processed meats, are associated with a higher risk for kidney strain, heart disease, and certain cancers.” He adds that processed meats, rich in saturated fats and sodium, can elevate cholesterol and blood pressure, both key contributors to heart disease.

 

The World Health Organization (WHO) has also classified processed meat as carcinogenic and red meat as “probably carcinogenic”, due to compounds formed during smoking, curing, or high-heat cooking.

 

How does too much protein affect the body?

 

When consumed in large quantities, protein increases the body’s nitrogen load, a by-product of its metabolism, forcing the kidneys to work harder. Dr Bhanu Mishra, Consultant-Nephrologist at Fortis Hospital, Shalimar Bagh, warns that “Excessive protein raises nitrogenous waste, thus placing a load on the kidneys by increasing glomerular pressure. Even in normal individuals, long-term high intake may lead to dehydration and mild stress.”

 

Over time, this can worsen kidney damage in those already dealing with diabetes, hypertension, or kidney disorders. Dr Manish Itolikar, Consultant – Internal Medicine, Fortis Hospital, Mulund, adds, “High protein diets can lead to glomerular hypertension and hyperfiltration, which may cause long-term injury to kidney tissues and even proteinuria (abnormally high protein in urine, a possible sign of kidney damage).”

 

Besides kidney strain, the high saturated fat content in red and processed meats can clog arteries, raise cholesterol, and increase blood pressure, all of which contribute to cardiovascular problems.

 

Can protein increase cancer risk?

 

The way protein-rich foods are prepared also influences their health impact. Dr Surakshith TK, Senior Consultant, Gastroenterology & Hepatology at Fortis Escorts, Okhla, notes, “Carcinogens, which include compounds like heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), may be produced when protein-containing foods are grilled, fried, or smoked at high temperatures.” These chemicals can damage DNA, increasing cancer risk.

 

Dr Tayal adds that safer cooking methods, such as baking, steaming, or boiling, can significantly reduce exposure to these compounds.

 

Why are plant proteins a better choice?

 

Doctors agree that shifting towards plant-based protein sources can help reduce long-term health risks. Lentils, beans, soy, nuts, and whole grains offer high-quality protein with added benefits like fibre, antioxidants, and healthy fats.

 

Dr Mishra emphasises, “Plant-based proteins carry less saturated fat and more fibre and phytonutrients. They promote cardiovascular and metabolic health while reducing inflammation and cancer risk.”

 

Similarly, Dr Tayal points out that “replacing some animal proteins with plant-based ones can help reduce the risk of heart disease, diabetes, and some cancers while protecting muscle and metabolic health.”

 

How much protein is enough?

 

The recommended daily intake of protein for adults is around 0.8 grams per kilogram of body weight, though athletes and those who exercise regularly may require up to 1.2–2.0 grams per kilogram. Dr Tayal advises focusing on quality and moderation, “Increase plant-based proteins and lean sources like fish, eggs, and low-fat dairy, and decrease red and processed meats. Distribute protein among meals and choose healthier cooking techniques.”

 

Ultimately, moderation is key. Protein is essential, but too much of a good thing, particularly from animal sources, could tip the scales toward disease rather than health.   

More from this series:

• From muscles to immunity: Why protein is important for your health
• Are you getting the right amount of protein for your body's needs?
• Protein overload: Why eating more isn't always better for your body
• What two boiled eggs a day can do for your strength, focus, and health
• Getting enough protein as a vegetarian is easier than you think: Here's how
• Protein on a budget: Everyday foods that outperform protein bars

 

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This report is for informational purposes only and is not a substitute for professional medical advice.