Yep, There’s Such a Thing as Eating Too Much Protein. Here's What a Dietitian Wants You to Know

You probably don’t need us to tell you that protein is absolutely essential. Often described as a critical “building block” for good health, this nutrient helps your body build muscle, clot blood, fight infection, and repair cells. 

But as good for you as protein is, you don’t want to consistently consume way more than your body needs. “Even the healthiest foods in the world can pose problems if we eat too much of them,” says Anthea Levi, RD, a registered dietitian based in Brooklyn, New York. But how much protein is too much protein?

Below, learn how to make sure you’re getting enough of this muscle-building macro to meet your goals without exceeding a healthy limit. 

How Much Protein Do You Need Each Day?

To figure out your daily protein needs, you’ll have to do a little math: The Academy of Nutrition and Dietetics recommends the average person eat about 0.8 grams of protein per kilogram each day, or 0.35 grams per pound. So if you weigh 165 pounds, you’d need at least 60 grams of protein in a day. 

But this guidance may not be right for everyone. Pregnant and breastfeeding women need more protein, for example, and as you age, your protein needs also increase. Around age 50, the American College of Sports Medicine (ACSM) recommends aiming for closer to 1 gram per kilogram of body weight (that’s about 0.45 grams per pound) to maintain muscle mass. For a person who is 165 pounds, that adds up to about 75 grams of protein per day.

People who exercise more often also have higher protein needs, especially if you’re trying to increase muscle while regularly training or lifting weights. If that describes you, the ACSM says you might need as much as 1.2–1.7 grams of protein per kilogram of body weight per day, or 0.5–0.8 grams per pound. Some experts suggest an even higher number—the International Society of Sports Nutrition, for instance, recommends some active individuals get up to 2 grams of protein per kilogram of body weight. That could mean up to 90–150 grams a day if you weigh 165 pounds, depending on your unique needs.

So how can you determine the best range for you? A solid place to start is the USDA’s handy Dietary Reference Intakes (DRI) calculator, which can help you pinpoint how much protein to aim for, as well as other important nutrients like carbohydrates, fats, and daily water intake. Your doctor or a registered dietitian can also help calculate the best protein intake for you, depending on your activity level and fitness goals.

Is It Possible to Eat Too Much Protein?

While you absolutely want to make sure your diet includes plenty of protein, it’s possible to overdo things and have too much. For starters, eating a ton of any particular food will probably make you feel… not great. The average person might have really uncomfortable gastrointestinal (GI) symptoms after eating too much protein, Levi adds.

The type of protein matters, too. Consistently eating more animal protein sources than your body needs has been linked to a higher incidence of kidney stones, as well as an increased risk of heart disease and colon cancer. All foods can be part of a healthy diet, but these risks are greater if you tend to eat lots of red meat, which contains more saturated fat. Seafood and leaner animal proteins like chicken or poultry contain less saturated fat, and plant-based proteins—think beans, legumes, and tofu—have even less.

How Much Protein Is Too Much?

In general, most people can process around 20–40 grams of protein in a meal—so “I wouldn’t recommend eating more than about 45 grams of protein in one sitting,” Levi says. (For context: One 100-gram steak contains about 25 grams of protein, so eating two—while delicious—might lead to a little discomfort.) According to Mayo Clinic, consuming more than 2 grams of protein per kilogram in the course of a day would also be considered on the high side for many people. 

But again, it’s hard to narrow down a specific, end-all-be-all number because protein needs are so individual, Levi says: Just as a person’s recommended daily allowance varies depending on their activity levels, age, and body weight, determining how much of this building-block nutrient is “too much” also depends on a number of factors. And what’s considered too much protein for one person might be just the right amount for someone else. (Remember, it’s never a bad idea to speak with your healthcare provider if you have any questions or concerns.)

Consequences of Eating Too Much Protein

Eating one protein-rich meal or loading up on more of the macro than average for a little while probably won’t lead to noticeable symptoms. But consistently eating much more of the nutrient than your body needs over long periods of time—particularly if you’re filling your plate with lots of red meat or processed proteins—can be detrimental to your health. Here are a few possible side effects to consider: 

1. You Might Experience GI Upset

Too much of any nutrient or food—yes, even broccoli!—can upset your stomach, Levi says. “Eating large amounts of protein can cause gastrointestinal symptoms,” she notes, adding that if protein is replacing fiber sources in your diet, you may start to experience constipation. But diarrhea and bloating are also possible, particularly if you’re eating lots of red meat.

2. You Could Be Hurting Your Cardiovascular Health

Speaking of red meat: If your diet includes a lot of beef or processed meats like hot dogs, sausages, deli meats, and bacon, you may be consuming unhealthy amounts of saturated fat. Over time, this can increase your low-density lipoprotein cholesterol levels (that’s the “bad” kind, FYI) and up your risk of heart disease as well, according to Mayo Clinic.

3. You Might Notice Bad Breath

If you’ve ever followed the keto diet or have known someone who has, you might have heard of something that’s often referred to as “keto breath.” According to the Cleveland Clinic, this can be a temporary side effect when your body enters a state of ketosis, which can happen when you’re eating lots of protein and fewer carbs. If you’re not trying to enter ketosis, keto breath might be a sign that you’re eating more protein than you need.

4. You Could Develop Kidney Issues

Your kidneys are in charge of many crucial functions, including removing waste from the body and filtering your blood. Over time, though, too much protein can make it hard for this organ to do its job: Lots of protein and not enough water can lead to dehydration, for one, as well as increase your risk of kidney stones. And it’s extra important to avoid high-protein diets if you already have kidney disease, since too much of this nutrient can force your kidneys to work harder and exacerbate this condition, the Cleveland Clinic notes.

How Can You Tell If You’re Eating Too Much Protein?

Other than experiencing some stomach discomfort or possible bad breath, you may not know if you’re overdoing your protein intake. Most negative side effects, such as heart disease, develop over time. But if you’re concerned that your diet might include too much of this nutrient, discuss what you’ve been eating with your doctor or a registered dietitian; together, you can determine if you’re in the right ballpark with your intake or whether it might make sense to cut back.

One possible symptom you definitely shouldn’t ignore, though? Foamy or bubbly-looking urine or facial swelling. These could suggest you have proteinuria, or too much protein in your urine, which could be a sign of kidney disease.

How to Get the Right Amount of Protein for Your Fitness Goals

So how can you nail down your ideal protein intake—and optimally reach that number? Here are a few pro tips:

The Takeaway

Protein is critical to your health, and it’s important to make sure you’re getting enough in your everyday diet. But it is possible to have too much of a good thing, especially because most Americans are already filling up on lots of animal proteins like eggs, poultry, and meat.

How much protein is too much will depend on personal factors like your age, weight, and activity level. Some experts recommend avoiding eating more than 45 grams of protein in one sitting and not eating more than 2–2.2 grams of protein per kilogram of body weight a day—but again, this number can vary on your unique circumstances.

A smart approach may be to focus on diversifying the kinds of protein you eat, and aiming for more plant-based sources and seafood. Make sure, too, that you know your RDI for protein, since it can vary a lot depending on your age, activity levels, and fitness goals. If you’re ever unsure, your doctor or a registered dietitian can help you figure out the right amount of protein for your situation.

This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.