6 Sneaky Signs of Eating Too Much Protein & Why It Matters

Protein is an essential part of a healthy diet, helping to build and repair tissues, support muscle growth and maintain a strong immune system. However, as with anything, too much of a good thing can have consequences. While any nutrition expert will tell you how crucial protein is for your health, consuming it in excess can lead to some sneaky and potentially dangerous health issues. 

Your protein needs depend on several factors, including age, sex, activity level and health status. Trista Best, RD, a registered dietitian with Balance One Supplements, tells EatingWell, “Sedentary adults generally need about 0.8 grams of protein per kilogram of body weight daily, while active adults may require 1.0 to 1.2 grams per kilogram. Athletes or those aiming for muscle gain should aim for 1.2 to 2.0 grams per kilogram.” A study published in Food & Function suggests that regularly consuming more than 2 grams of protein per kilogram of body weight may be excessive and result in “digestive, renal and vascular abnormalities.” Here are some subtle yet serious signs you might be consuming too much protein.

1. You’re Frequently Thirsty or Dehydrated

One of the first signs of excessive protein intake is constant thirst. “High protein intake increases the body’s need for water to flush out excess nitrogen, a byproduct of protein metabolism,” explains Best. If you’re always thirsty or dealing with a dry mouth, it could be a sign your body is working overtime to process the extra protein.

Chronic dehydration can lead to kidney issues, low energy and impaired bodily functions. That’s why staying hydrated is essential when consuming a high-protein diet.

2. You’re Experiencing Digestive Issues

If you’re experiencing bloating, constipation or gas, your protein-heavy diet could be a contributing factor. “Digestive issues often arise when people prioritize protein over fiber-rich foods like fruits, vegetables and whole grains,” Best says. “A lack of fiber slows down digestion, leading to gastrointestinal discomfort and even long-term gut imbalances.”

To help prevent these issues, ensure your diet includes plenty of fiber-rich foods like oats, leeks, berries, legumes and bananas to support healthy digestion and gut health.

3. You Have Bad Breath

Research indicates that a low-carb, high-protein diet can cause a distinct, unpleasant breath odor. “When your body lacks carbohydrates, it enters a state of ketosis, burning fat for fuel and producing ketones, which can lead to bad breath,” explains Best.

Though bad breath from ketosis isn’t harmful, it’s a sign that your diet might be unbalanced. Including more healthy carb-rich foods like whole grains, fruits, vegetables and dairy can help mitigate this issue while providing your body with a more sustainable energy source.

4. You Experience Kidney Health Problems

Your kidneys filter waste products from protein metabolism, including nitrogen. “Too much protein can increase the risk of kidney stones and, in severe cases, kidney damage,” warns Best. “If you notice kidney pain or changes in urination, it might be time to reevaluate your protein intake.” Talk to your doctor if you have concerns about your kidney health. 

5. You’re Gaining Weight Unintentionally

While protein is often associated with weight loss, eating too much can have the opposite effect. “Consuming more protein than your body needs can result in excess calorie intake, which can be eventually stored as fat. This is particularly true if your extra protein comes from high-calorie sources like fatty meats or full-fat dairy. Over time, this caloric surplus can lead to weight gain and potentially contribute to metabolic issues,” says Best.

6. You Have Reduced Energy Levels

If you’ve noticed yourself feeling low on energy, an imbalanced diet might be to blame. Protein-rich diets that skimp on carbohydrates can leave your body low on glucose (its preferred energy source) and feeling depleted.

Best says, “Excess protein without enough carbohydrates can cause low energy and mood swings. Carbohydrates are essential for maintaining stable blood sugar levels and fueling your brain. Without them, you may experience fatigue, brain fog and irritability.”

The Bottom Line

Protein is essential to a balanced diet, but too much of it can lead to dehydration, digestive issues, kidney strain, bad breath, weight gain and low energy. To avoid the risks of eating too much protein, consider pairing protein-rich foods with fiber-rich fruits, vegetables and whole grains, and make sure you stay hydrated. As always, speak with a health care provider or registered dietitian to determine the right amount of protein for your needs.