Eating too much protein can lead to several short-term and long-term health issues, depending on the amount and duration of overconsumption.
Short-term effects of excessive protein intake
- Digestive discomfort: Symptoms like nausea, intestinal discomfort, constipation, and fatigue can occur due to excess protein
- Increased urination and dehydration: The kidneys work harder to eliminate nitrogen waste from protein metabolism, leading to more frequent urination and potential dehydration, which may cause headaches, dizziness, and brain fog
- Bad breath: Excess protein can cause changes in metabolism that sometimes result in unpleasant breath
Long-term risks of chronic high protein consumption
- Kidney strain and damage: High protein intake increases kidney workload by causing glomerular hyperfiltration and may lead to kidney injury, especially in those with pre-existing kidney conditions
- Liver stress: Excess protein metabolism can strain the liver, potentially leading to liver dysfunction or disease over time
- Cardiovascular disease: Diets very high in protein, particularly from animal sources high in saturated fat and cholesterol, have been linked to increased risk of heart disease and blood vessel disorders
- Increased cancer risk: High intake of protein from certain sources, especially red and processed meats, may raise the risk of some cancers
- Bone health concerns: Excess protein may affect calcium balance and bone health negatively, though evidence is mixed
- Hormonal imbalances: Very high protein diets may reduce testosterone and increase cortisol levels, potentially impacting men's sexual health and fertility
Additional considerations
- Weight gain can occur if excess protein calories are stored as fat, especially if total calorie intake is too high
- Most adults need about 0.8 g of protein per kg of body weight daily, with safe upper limits around 2 g/kg for most people and up to 3.5 g/kg for athletes
- Consuming more than about 22% of daily calories from protein may have more risks than benefits
In summary, while protein is essential for health, consuming too much- especially over long periods-can cause digestive issues, dehydration, kidney and liver strain, increased cardiovascular and cancer risks, and hormonal disturbances. Moderation and balanced protein intake aligned with individual needs are recommended to avoid these adverse effects
