What Happens if You Have Too Much Protein Intake?

Although protein is an essential nutrient your body needs daily to function properly, getting too much protein can lead to unpleasant -- and dangerous -- side effects. Nutrient deficiencies may occur if you're eating protein in place of other essential nutrients. Aim to consume protein in recommended amounts to optimize your health.

A woman is talking to her doctor about stomach pains. (Image: Iakov Filimonov/iStock/Getty Images)

Recommended Daily Intake

Keep your protein consumption to approximately 35 percent of your daily calorie needs, recommends the Institute of Medicine. Protein provides 4 calories per gram. Therefore, individuals consuming 2,500 calories daily should aim for about 219 grams of protein, those who consume 2,000 calories a day should avoid eating more than 175 grams of protein and individuals following 1,600-calorie diets should consume about 140 grams of protein daily.

Side Effects

A 2006 review published in the "International Journal of Sport Nutrition and Exercise Metabolism" reports that excess protein intake can cause nausea and diarrhea. If you couple a high protein intake with a low-carb diet, you may also experience fatigue, headaches and weakness. A study published in 2010 in "Annals of Internal Medicine" notes that participants who followed a high-protein, low-carb weight-loss diet reported bad breath, hair loss, dry mouth and constipation.

Danger Zone

Getting too much protein, especially long-term, can even lead to dangerous side effects and may cause health problems. The 2006 review in the "International Journal of Sport Nutrition and Exercise Metabolism" reports that excess protein can exceed your liver's ability to properly break down and excrete the protein, which can lead to toxin buildup in your blood or even death. A study published in 2012 in the "American Journal of Kidney Disease" found that following a high-protein diet over the long term may lead to kidney disease.

Minimum Protein Needs

While eating too much protein can be harmful, not getting enough protein is also problematic. Protein malnutrition can lead to decreased muscle mass, hair and skin changes, irritability, a weakened immune system and even swelling or shock, according to MedlinePlus. The Institute of Medicine suggests men eat at least 56 grams of protein daily, women consume 46 grams and pregnant and nursing women obtain at least 71 grams of protein daily. Protein-rich choices include eggs, lean meats, poultry, seafood, low-fat dairy foods, soy products, seitan, nuts, seeds and legumes.