Protein comes up so much in advice about how to maintain a healthy weight and stay in shape that it can be easy to think that more is always better. But while there are some circumstances when an individual may need extra protein in their diet, such as when healing from surgery, competing as an elite athlete, or experiencing health risks due to muscle loss with age, most people don’t need more than the recommended daily amount of protein, says Kristin Kirkpatrick, RDN, registered dietitian-nutritionist at the Cleveland Clinic in Ohio and founder and president of KAK Consulting.
The current U.S. recommended dietary allowance (RDA) of protein for most adults is 0.8 grams per kilogram of body weight, which is about 51 grams for a 140-pound adult. You can almost meet that guidance just by eating a 3.5-ounce (oz) Greek yogurt at breakfast and a 4-oz serving of boneless, skinless chicken breast with pasta at lunch or dinner.
Before you try a high-protein eating plan, talk with a health professional who is well-versed in nutrition such as a registered dietitian. Eating a high-protein diet for a brief period of time isn’t likely to have negative effects on people who are generally healthy, but following this type of a diet long-term can increase your risk for certain health issues, particularly if you have underlying chronic conditions such as high cholesterol or kidney problems. And if you see any of the following signs that you may be getting too much protein, contact your doctor.
1. Dehydration
When you eat more protein than your body needs, your kidneys work overtime to process it. As protein gets metabolized, nitrogen — a component of amino acids in protein — needs to be purged from the body. Over time, this can lead to dehydration.
“The only way the kidneys can discard the excess nitrogen is by increasing urination and thus you become dehydrated as a result,” says Babak Razani, MD, PhD, a cardiology professor at the University of Pittsburgh School of Medicine.
Symptoms of dehydration can include feeling thirsty, tired, dizzy, or lightheaded as well as experiencing unusually dry skin, sunken eyes, or dryness in your mouth.
2. Foamy or Bubbly Urine
If your urine looks foamy, it can be a sign of proteinuria, or a high level of protein in your urine — a potentially-serious condition that can be an indicator of kidney damage. While more research is needed, some studies have shown that there may be a link between eating high amounts of protein and proteinuria, according to a review.
You may also feel like you have to pee all the time, which is another symptom of proteinuria and might be another indication that you’re eating too much protein. (The same processes in the body that can cause dehydration when you consume too much protein can also cause frequent urination, says Kirkpatrick.)
3. Kidney Stones
While eating excess protein, specifically, animal protein, doesn’t typically lead to kidney stones, this is something to watch out for, especially if you have either a history of kidney stones or risk factors for the condition, such as being prone to urinary tract infections, says Dr. Razani. Telltale signs of kidney stones can include sharp pain in the side, lower back, and abdomen; pain during urination; and blood in the urine.
Eating too much animal protein can lead to kidney stones because frequent urination to purge excess nitrogen from the kidneys can upset the typical acidity levels in the urine and trigger production of oxalates, substances in the liver that form kidney stones, Razani says.
4. Irregular Bowel Movements
Eating any nutrient in excess — including protein — can make it hard to digest and lead to digestive issues such as constipation, Razani says. Constipation is common when you eat too much protein because most people do this by cutting back on other nutrients like fiber and lack a balanced diet to regulate the bowels, Razani says.
“If high protein dietary patterns are deficient in fiber, then bowel issues may be the result of such low fiber intake,” Kirkpatrick says.
5. Weight Gain
High protein diets are promoted as a good way to reduce your hunger levels so you eat fewer overall calories, Razani says, so it may seem counterintuitive that eating too much protein could lead to weight gain. But the fact is, there’s a lack of scientific evidence to back up claims that high-protein diets lead to weight loss, and some may actually experience weight gain.
The problem: Not everybody actually eats less on a high protein diet. “Excess protein intake, if balanced by less intake of other foods, is good for weight loss,” Razani says. “But if your total calorie intake is higher than before even if it is all in the form of protein, then weight gain occurs.”
How to Reduce Protein Intake
Most people eat more protein than they need, even when they’re not trying to follow a high-protein diet, Razani says. For example, you’ll get around 17 grams of protein from a 3-oz serving of cooked cod and 26 grams of protein in a 4-oz serving of boneless, skinless chicken breast — and those portions are far smaller than what many people put on their dinner plates. Plus, you can also get 8 grams of protein in a cup of milk or a cup of cooked pasta — foods that might not necessarily be on your radar as protein sources.
Two good ways to reduce your total protein intake are to focus on your portion sizes and make sure you include other nutrient-rich foods. Following a Mediterranean style diet rich in whole grains, fresh fruits and vegetables, nuts, legumes, olive oil, and lean poultry and fish can also help you get a balanced diet with the right amount of protein and other nutrients, Razani says. “There is a lot of data to suggest that this diet, with about 15 percent of calories from protein mixed with healthy fats, and complex carbohydrates is the best overall healthy diet for the majority of us,” he says.
The Takeaway
Most people eat too much protein, which can cause extra work for your kidneys and lead to a lot of uncomfortable symptoms such as frequent urination and constipation, and possible health issues over time. The best approach to cut back on excess protein is to watch your portion sizes and include other types of foods such as fruits, vegetables, and whole grains in your diet. And before you up your protein intake or embark on any big changes in your diet, talk to your doctor or see a registered dietitian.
Reyna Franco, RDN, is a New York City–based dietitian-nutritionist, certified specialist in sports dietetics, and certified personal trainer. She is a diplomate of the American College of Lifestyle Medicine and has a master's degree in nutrition and exercise physiology from Columbia University.
In her private practice, she provides medical nutrition therapy for weight management, sports nutrition, diabetes, cardiac disease, renal disease, gastrointestinal disorders, cancer, food allergies, eating disorders, and childhood nutrition. To serve her diverse patients, she demonstrates cultural sensitivity and knowledge of customary food practices. She applies the tenets of lifestyle medicine to reduce the risk of chronic disease and improve health outcomes for her patients.
Franco is also a corporate wellness consultant who conducts wellness counseling and seminars for organizations of every size. She taught sports nutrition to medical students at the Albert Einstein College of Medicine, taught life cycle nutrition and nutrition counseling to undergraduate students at LaGuardia Community College, and precepts nutrition students and interns. She created the sports nutrition rotation for the New York Distance Dietetic Internship program.
She is the chair of the American College of Lifestyle Medicine's Registered Dietitian-Nutritionist Member Interest Group. She is also the treasurer and secretary of the New York State Academy of Nutrition and Dietetics, having previously served in many other leadership roles for the organization, including as past president, awards committee chair, and grant committee chair, among others. She is active in the local Greater New York Dietetic Association and Long Island Academy of Nutrition and Dietetics, too.
Lisa Rapaport is a journalist with more than 20 years of experience on the health beat as a writer and editor. She holds a master’s degree from the UC Berkeley Graduate School of Journalism and spent a year as a Knight-Wallace journalism fellow at the University of Michigan. Her work has appeared in dozens of local and national media outlets, including Reuters, Bloomberg, WNYC, The Washington Post,Los Angeles Times, Scientific American, San Jose Mercury News, Oakland Tribune, Huffington Post, Yahoo! News, The Sacramento Bee, and The Buffalo News.
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
Weiler M et al. Is It Time to Reconsider the U.S. Recommendations for Dietary Protein and Amino Acid Intake? Nutrients. February 6, 2023.
