How Much Protein is Too Much?

by | Updated: August 26th, 2019 | Read time: 4 minutes

Protein is a vital contributor to muscle, bone, tissue and joint health, as one of the three macronutrients the human body needs. Before talking about how much you need, however, here’s a quick science lesson from Harvard Nutrition Source:

Woman's Hands Holding Chocolate Protein Powder Container to Represent Question of How Much Protein is Too Much | Vitacost Blog

Protein is made of organic compounds known as amino acids, which generate all cellular functions. There are nine essential amino acids the body cannot manufacture on its own. As such, these must be absorbed through foods rich in protein.

As such, a high-protein diet, combined with regular exercise, can boost your muscle strength, bone density, metabolic function and lean body mass, according to the Journal of the International Society of Sports Nutrition.

However, consuming too much protein can also be risky. Get familiar with the indicators of excessive intake, and find out why it matters and how can you maintain a healthy protein balance for your fitness goals.

How the body reacts to excess protein levels

The Food and Function Journal explains that the body is designed to oxidize amino acids into water-soluble byproducts, such as ammonia—these are then used to fuel your cells and therefore your workout. When their job is done, they’re filtered out when you use the bathroom.

If you consume more protein than what can be metabolized in a single day, over time, you’ll experience excess ammonia because it remains in the body. This impacts how the liver, kidneys and intestines function, causing:

  • Dehydration
  • Intestinal discomfort
  • Nausea
  • Diarrhea
  • Headaches
  • Fatigue
  • Seizures
  • Heightened insulin
  • Toxins in the bloodstream
  • Increased risk of cardiovascular disease

How to know if you’re eating too much protein

The upper limit for most active, healthy adults’ recommended daily allowance (RDA) of protein is 2 grams per kilogram of body weight. Endurance or strength trainers who consume protein to boost their athletic performance can have as much as 3.5 grams and still be within a safe range, according to the report, Dietary protein intake and human health.

Consuming higher levels of protein for an extended amount of time will lead to adverse physical effects. For example, in a study of 40 resistance-trained athletes who ingested 4.4 grams of protein over the course of 8 weeks, 10 dropped out because of a stated inability to tolerate that much protein. One individual also suffered gastrointestinal distress and chronic elevated body temperature.

While the increase in protein had no visible impact on their body composition, it lead to discomfort and unwanted health outcomes. If you start to observe these issues in your own body, it could be an early indicator of excessive protein intake.

How to determine your optimal protein intake

There are a number of variables that factor into your specific range of healthy protein consumption, including gender, body mass, exercise level and age bracket. As a baseline, however, you can plan for 15 to 20 percent of your entire daily caloric intake to come from protein.

For example, a 50-year-old woman, who is 140 pounds and is not active should consume 53 grams of protein on a daily basis, explains Harvard Health. If you’re not sure about the math, use the calculator from the Food and Nutrition Information Center as a starting point.

Another consideration to make is where your protein comes from. Whether you choose to eat plant-based proteins or animal-based proteins, it’s important to understand that not all protein-rich foods yield the same health benefits. To illustrate this point, Harvard Nutrition Source shares a breakdown of four different protein sources and how each of their nutritional profiles compare:

  • A 4-ounce beef sirloin steak contains 33 grams of protein, but it has 5 grams of saturated fat.
  • A 4-ounce ham steak contains 22 grams of protein and just 1.6 grams of saturated fat, but it has 1,500 milligrams of sodium.
  • A 4-ounce salmon contains 30 grams of protein, 1 gram of saturated fat, trace amounts of sodium, and is high in omega-3 fatty acids.
  • A 1-cup serving of lentils contains 18 grams of protein, 15 grams of fiber, and has virtually no saturated fat or sodium.

As you can see, not all protein is created equal. Consider the fat, sodium and caloric values when planning your meals to ensure you’re staying on track with all your health goals.

Know your protein needs

Don’t go overboard with protein. Instead, stick to the  proper daily allowance to be sure you’re giving your body what it needs, and avoiding the adverse effects of eating too much. However, you’ll more likely struggle with getting enough each day, so focus on regularly eating a diverse range of protein sources first and foremost.