You’d think that something so important wouldn’t fall under the “you can’t get too much of a good thing” category, right? Wrong. Here are some signs of eating too much protein, and the best types to prioritize in your diet. 

Why we need protein

More than amino acids, protein has a slew of benefits for our body. There are two types of protein: Complete protein includes all of the nine essential amino acids that we require from our diet, and incomplete protein is missing one or more of those amino acids. More than helping to maintain health, protein also plays a role in skeletal and muscle growth, cognitive development, and cellular function.  “You may have heard that protein is needed for muscle growth and increasing strength, but it also helps with repairs, plays a big role in keeping our immune system strong, maintains proper pH and fluid balance, transports and stores nutrients and finally can act as an energy source if it’s needed,” explains Mona Cabrera, MS, RDN, nutrition consultant for RSP Nutrition. “Protein can  also help with weight loss and our metabolic health because it helps keep us full by reducing our hunger hormone ghrelin and increases our hormone peptide YY, which is our hormone that makes us feel full.”   There are some proteins that we hear about more than others; Silvia Carli, MS, RD, CSCS, LD, a nutritionist for 1AND1 LIFE uses collagen as an example, as it is “the most abundant protein in the body.” Because protein is so important to the function of the body, it’s important to focus on getting enough, and making sure the majority is high-quality.

What are the best sources of protein?

So what exactly are high-quality proteins, and does it matter if they’re complete or incomplete? Generally, complete proteins are animal-based, and incomplete are plant-based. You can combine different types of incomplete proteins to get all the amino acids you would from a complete protein. Whether you eat a diet including animal products or just a plant-based one, there are high-quality protein options out there for you.  “The highest quality proteins are from animal sources: lean meats, eggs, fish are the most bioavailable sources of protein,” notes Carli. “For the vegan counterpart—or just for an omnivore that wants to include variety—soy protein is also very high in quality and digestibility.”  The protein source you choose will depend on your specific dietary needs and sensitivities. Additionally, activity level and age can be taken into account, especially if you use protein to post-workout.  “Whichever protein you choose, it’s important that you eat what you need individually for your body to work at its best,” adds Cabrera.  Cabrera notes common animal-based proteins options are:

Fatty fish (such as salmon)SardinesWhite-meat poultry (chicken or turkey breast)Egg and egg whitesDairy

Cabrera notes common plant-based protein options are:

BeansLegumesTofuTempehSoybeans 

Should you be looking to get protein in the form of a protein powder, which is most commonly used to supplement the body post-exercise, Carli shares that whey is quickly and efficiently absorbed, it’s ideal for post-workout. Because it does come from milk, a vegan would not want to use whey protein, however. If that is the case, or you have a dietary sensitivity to whey products, pea protein can be a suitable option. 

Can you eat too much protein?

There are international guidelines for a Recommended Dietary Allowance (RDA) of protein: 0.8 grams per kilogram of body weight. However, recent research has found that this should ideally be the minimum amount of protein consumed, calling for evaluation of the current recommendations. It has been argued that physical activity and age should also be considered, especially as activity levels often decrease as we age, citing a correlation between the two. “Physically active people—especially athletes and bodybuilders—do require more protein in their diet than people who are sedentary,” confirms Cabrera.  While we know it is possible to eat too much protein, unfortunately there isn’t a definitive amount that can be given. Some guidelines note that high-protein intake starts when consuming more than 2 grams per kilogram of body weight per day. However, many researchers have pushed back against the guidelines and recommend eating more protein than the RDA suggests. Whether or not you are eating too much protein will depend in part on your age and activity level, but it has been suggested that for adults who are moderately active, roughly “10 percent of your calories should come from protein.”  

Signs you might be eating too much protein

Just as with the amount of protein you should consume, more research is needed to confirm some of the purported serious risks of eating too much protein. Cabrera notes that there are some symptoms to look out for, however, that may be a sign that you’re consuming too much protein. 

Symptoms of too much protein

Cabrera specifically notes consuming too much protein may cause:

Indigestion Intestinal discomfort DehydrationNausea Diarrhea Irritability, Constipation Bad breath Weight gain TirednessBad mood 

Serious risks of too much protein

As for serious risks, this is where the research gets a bit murky. Some of the noted serious side effects of high-protein consumption include:

Increased risk of coronary heart disease (“ due to intakes of saturated fat and cholesterol”)Increased risk of cancerIncreased risk of diabetesThe possibility of renal abnormalities

For some of these risks, more research has been called for. If you are concerned about your protein intake, are commonly experiencing some of the symptoms above or think you may be consuming too much protein, it is best to consult your doctor for further testing and to discuss the appropriate amount of protein to include in your daily diet. Next up, read up on easy (and delicious) ways to eat more protein.

Sources

Mona Cabrera, MS, RDN, nutrition consultant for RSP NutritionSilvia Carli, MS, RD, CSCS, LD, a nutritionist for 1AND1 LIFERoyal Society of Chemistry: “Dietary protein intake and human health"Nutrients: “Protein For Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect of Appetite in Aging Adults.“ISRN Nutrition: “Adverse Effects Associated with Protein Intake Above the Recommended Dietary Allowance for Adults.“Cell Metabolism: “Low protein intake is associated with a major reduction in IG-F 1, cancer, and overall mortality in the 65 and younger but not older population.“Nutrients: “Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit.” Can You Eat Too Much Protein  How Much Protein Is Too Much - 26