Today’s high-protein diet takes many forms. From the Atkins diet to the paleo diet and even some versions of the keto diet, protein is often touted as the miracle macronutrient. You’ve probably seen countless protein shakes, bars, and protein-fortified foods lining the shelves of your local grocery store.

How much protein do we need?

But first, let’s clear the air…protein is a critical component of our diet. It’s involved in virtually every biochemical function in our body, from building and repairing tissues to producing enzymes and hormones.

So, how much protein do our bodies need to conduct these essential tasks? To get a better idea, we spoke with Registered Dietitian, Jamie Kesmodel, MS, RDN, who works at Culina Health, a nationwide nutrition care provider.

The current recommended dietary allowance (RDA) for protein is 0.36 grams per pound (or 0.8 grams per kilogram) of body weight per day for adults. For example, a 175-pound person with an average physical activity level should aim to consume about 70 grams of protein per day. Or looking at it from a caloric standpoint, you should consume about 10%-35% of your calories as protein, which equates to 50 to 175 grams a day on a 2,000 calorie diet.

However, Kesmodel points out there’s no assigned gram amount per day for everyone, as our body’s protein needs are highly individualized, based on our body weight, muscle mass, activity level and duration, among other factors. Because of this, protein needs could increase to 1-1.5 grams per kilogram of body weight per day for those with rigorous physical activity or building muscle mass.

And others in the medical community push that recommendation even higher. Dr. Peter Attia, author of New York Times Bestseller, Outlive: The Science & Art of Longevity, stated in his podcast that most people are not getting enough protein. He continued, saying that the current RDA of 0.8 grams per kilogram of body weight is a “pathetic” amount and should be revised to 1 gram per pound of body weight.

But estimating this higher level of protein consumption is where things get murky because, as it turns out, several larger-scale, peer-reviewed studies reveal that consuming too much protein can have some pretty significant downsides.

Protein’s effect on the body

Despite protein’s necessity in our diet, myriad health risks may occur when consuming too much. Kesmodel highlighted some of the ways consuming too much protein may affect various organs and functions of our body.

Kidney & liver function

Our kidneys play a crucial role in processing or filtering the waste products from protein metabolism. When you consume excessive amounts of protein, we’re essentially making our kidneys work overtime. For those with existing kidney issues, this can quickly become a dire situation.

Separately, long-term protein supplementation has been associated with elevated levels of liver toxicity, apoptotic signals, and inflammation in some studies. But not all medical experts agree with this level of concern. Dr. Attia thinks that most people will never reach these concerning levels of protein, requiring most individuals to consume 3 to 4 grams of protein per kilogram of body weight.

Heart health

While protein itself isn’t necessarily bad for your cardiovascular system, the problem often lies in the source of protein. High-protein diets that rely heavily on saturated fats, like red meat, cheeses, and processed meats, may increase your intake of saturated fats, which are known risk factors for heart disease.

Cancer risk

Some studies have suggested that high consumption of red and processed meats may increase the risk of certain types of cancer, particularly colorectal cancer. Colorectal cancer, previously considered a threat to those over the age of 60, is now the leading cause of cancer death among adults under 50.

Weight gain

Surprisingly, excessive protein intake can hinder weight loss efforts.

While protein can help you feel full and satisfied, consuming more protein than your body needs doesn’t magically become muscle…some of the excess protein is stored as fat, if it’s not excreted as waste or broken down for energy.

Furthermore, be mindful of how you’re consuming protein. If you opt for highly-processed, shelf-stable protein bars and shakes, you’ll have less room in your diet for the fresh foods critical for long-term health: veggies and fruits.

Toxin exposure

Registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard’s Brigham and Women’s Hospital, stated that many protein powders contain heavy metals, like lead, arsenic, cadmium, and mercury. A study reported in the journal Toxicology Reports found similar results, as well as additional contaminants linked to cancer and health conditions.

Type 2 diabetes risk

Excessive intake of whey protein may influence the onset of Type 2 diabetes through several physiological mechanisms, including insulin resistance due to high levels of branched-chain amino acids (BCAAs), including leucine.

Other findings

Recent research from the University of Missouri School of Medicine and the University of Pittsburgh found that consuming too much protein (e.g., 100 grams in a 2,000-calorie diet) may trigger cardiovascular and metabolic health issues.

Though these findings may be concerning, the study only had 23 human participants, and the results incorporated mice and cell studies. It should be further replicated with a higher sample size before reconsidering limitations, especially when revising nutritional guidelines.

What can we do to eat healthier?

So, what’s the takeaway here? Protein is still an essential nutrient, and getting enough is crucial for our health. As with most things in nutrition, the key is balance.

So we asked Jamie for some insightful tips to help us strike that protein sweet spot:

Focus on quality, not quantity

Choose whole foods when you can. Lean meats, fish, eggs, legumes, low-fat dairy, and plant-based proteins like nuts and seeds not only provide protein but also pack other beneficial nutrients.

Spread your protein intake throughout the day

Instead of loading up on protein at one meal, try to include a moderate amount at each meal. This can help with better absorption and utilization of the protein.

Don’t forget about other nutrients

A balanced diet includes carbohydrates and healthy fats, which provide an abundance of essential vitamins, minerals, and other micronutrients. Don’t let your protein obsession crowd out nutrient-dense foods, like avocadoes, leafy greens, berries, and olive oil.

Listen to your body

If you’re experiencing digestive issues, feeling overly full, or noticing other unusual symptoms after increasing your protein intake, it might be time to dial it back a bit.

Consider your individual needs

The human body is incredibly complex, and factors like overall diet, exercise habits, genetics, and individual health status all affect how we process nutrients.

Athletes, pregnant women, and older adults need more protein than the average person. Conversely, people with certain health conditions might need to limit their protein intake.

Be wary of protein supplements

There’s no doubt about it: protein powders are convenient.

However, these protein powders, bars and other products are highly processed.

And most contain added sugars, artificial ingredients, and other less savory additives that may conflict with your overall health goals.

At D2D, we like single-ingredient protein supplements, like pea or whey protein.

Keep an eye on your overall calorie intake

Remember, excess protein doesn’t magically turn into muscle—it can contribute to weight gain if you consume more calories than you burn.

Do your research

Nutrition science is complex and constantly evolving. What we know today might be different from what we’ll discover tomorrow. That’s why it’s always a good idea to stay informed, but also verify dramatic diet claims. And always speak with your doctor to ensure that you are on the right protein track.