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, most people don’t need more than the recommended daily amount.
“People may need more protein when healing from surgery, competing as an elite athlete, or experiencing health risks due to muscle loss with age, but most of us 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 or nutritionist.
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 metabolised, 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 fibre and lack a balanced diet to regulate the bowels, Razani says.
“If high protein dietary patterns are deficient in fibre, then bowel issues may be the result of such low fibre 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.
“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,” Razani says.
