If you’re interested in weight loss or improving your overall health, you probably spend at least a portion of your time thinking about the amount of carbohydrates and fats you eat. But unless you’re a professional athlete or bodybuilder, you probably don’t spend nearly as much time pondering your protein intake. However, our bodies are made up of approximately 15% protein, which we need for everything from building muscle to manufacturing hormones and maintaining and repairing tissues. When you really start to think about everything protein does for your health, you may find yourself asking, how much protein should I eat? If so, we invite you to read on to discover your optimal dietary protein intake for overall health and well-being.
The Dietary Reference Intakes
The National Academy of Sciences dietary reference intakes (DRIs) are widely accepted as the most authoritative source for defining nutritional requirements. In fact, the DRIs are the basis for the more commonly recognized recommendations from the United States Department of Agriculture (USDA) called the Dietary Guidelines for Americans—translated for the public as MyPlate.
The DRIs define the recommended dietary allowance (RDA) for a wide range of micronutrients (vitamins and minerals) as well as proteins and carbohydrates (but not fats). The DRIs also indicate the recommended dietary intake of proteins, carbohydrates, and fats in terms of a percentage of total calorie intake.
The Recommended Dietary Allowance
The RDA for protein is 0.8 grams for every kilogram of body weight. If we convert that to the English equivalent of 2.2 pounds, that would mean a 175-pound person needs to eat about 63 to 65 grams of protein (or 2.2 ounces) per day to meet the RDA.
However, the average American eats approximately 4 to 5 ounces of protein per day, or about twice the RDA. This may seem like a small amount of protein if you have a 10-ounce steak on the menu for dinner tonight. But it’s important to distinguish the intake of pure protein—which is what’s reflected by the dietary guidelines—from protein food sources.
What do we mean by this?
Even a high-quality protein source like lean meat isn’t pure protein, as it also contains fat and micronutrients like vitamins and minerals. But there are still approximately 7 grams of protein in 1 ounce of red meat, so a 175-pound person can indeed satisfy the RDA for protein by eating a 10-ounce steak. However, there are many sources of protein in the average diet, many of which have less protein per gram than steak.
Nevertheless, if you add up all the protein food sources you might eat in a day, including breakfast with eggs, yogurt, or cereal with milk; lunch with ice cream or pudding for dessert; and dinner with salmon, chicken breasts, or pork chops, you’re still probably eating at least twice the RDA for protein.
And if you add to the obvious protein sources the protein contained in foods like wheat, peas, potatoes, soy, etc., you’re likely eating quite a bit more than the RDA.
Does eating more protein than the RDA suggests lead to health issues like obesity and diabetes? Some health professionals believe so. And research does suggest that too much protein may be harmful for people with kidney disease.
However, it’s important to remember that the RDA is defined as the minimum amount that should be eaten to maintain body protein. In other words, the RDA refers to the lowest dietary protein intake at which the rates of protein synthesis and breakdown are theoretically matched throughout the day.
As for sticking to this minimum, there’s never been a health outcomes study that’s shown that eating the RDA for protein is preferable to eating a greater amount of protein.
Dietary Protein Intake as a Percent of Total Calories
In addition to the RDA, the DRIs recommend that protein intake fall within a certain percentage of total calorie intake. Since all the food we eat is in the form of three macronutrients—carbohydrates, fats, and proteins (four if you include alcohol)—the DRIs committee accounted for the fact that the amount of each macronutrient eaten will influence the amount of the other macronutrients in the diet.
For example, if you eat a high-protein diet, you are simultaneously decreasing the amount of fats and/or carbohydrates you eat. And recommended ranges of calorie intake for each macronutrient were set to account for this interrelationship.
In the case of dietary protein, the DRIs recommend that total intake constitute between 10% and 35% of dietary calorie intake. However, the DRIs also state that there’s no evidence of harmful effects with intakes above this level.
For a person of average body weight with a relatively low activity level, the RDA for protein provides about 10% of the day’s total calorie intake—the lower limit of the range for protein. Yet a diet providing 3.5 times more protein is still within the recommendations of the DRIs.
But a dietary protein intake recommendation with a range of 3.5 times (or more) can hardly be considered a useful guideline. Consequently, we have to accept that the “experts” have let us down—at least as far as giving us concrete guidelines for ensuring we’re eating enough protein.
So we need to figure this out for ourselves. And the best way to start doing this is by understanding the difference between minimal and optimal protein consumption.
Minimal vs. Optimal Protein Consumption
The RDA for protein corresponds to about 10% of daily calories. This is the minimal amount of protein we need to eat to avoid loss of muscle mass. Since the RDA is equivalent to only about 10% of dietary calories, you might consider protein content a minor component of your diet.
But this perspective is missing the boat.
In fact, protein should take center stage in almost every person’s diet. Likewise, there’s a particularly good argument for the centrality of protein in an athlete’s diet in terms of both muscle mass and strength.
More generally—and as we briefly touched on earlier—dietary protein has a central role in the body’s nutritional arsenal against the chronic diseases and stresses many of us deal with every day. Indeed, many of these beneficial effects are related to dietary protein’s influence on muscle.
So the starting point of any nutritional approach to improving physical health and performance is a balanced diet that contains the optimal—rather than minimal—amount of protein.
So How Much Protein Should I Eat?
If you’re still wondering how much protein you need, the scientific data indicate the optimal level is even greater than the RDA of 10% of daily calorie intake.
However, the average American’s protein consumption is about 20% of their daily calorie intake—a perfectly reasonable amount for anyone striving to meet their daily protein requirements.
While consuming more protein may provide further benefits, the total amount of calories from protein food sources makes greater protein intake difficult to accomplish in the context of a balanced diet.
And that’s where amino acids—the building blocks of protein—and amino acid supplements can come in handy.
The potential role of essential amino acid supplementation in achieving optimal daily protein intake becomes even more evident when you consider that supplements provide the active components of dietary proteins without the accompanying non-protein components (carbs and fats) found in food sources. Even protein supplements like protein powders may be loaded with added sugar, calories, and artificial ingredients.
So if you’re struggling to meet your protein needs (a distinct possibility if you’re vegan) and want to build muscle—or maybe you’re an older adult who wants to ensure you’re at least not losing important muscle tissue—you may want to look into supplementing your daily protein intake with amino acids.
Just make sure you look for a formula that provides a balanced supply of all nine essential amino acids. That way, you can be sure you’re getting all the benefits amino acid nutrition can provide.