51 Facts About Your Dietary Protein Intake
There is a lot of information out there on how best to manage your protein intake. You can search and easily find information telling you protein can prevent cancer, help you lose weight, prevent heart disease, and even slow down aging!
Claims without citations make it difficult to know what is true, what has been exaggerated, and what is flat out false.
After some research into the scientific literature, scouring blogs from nutritionists, and combing through reports from health institutions like the Centers for Disease Control (CDC), the National Academy of Medicine, the American Heart Association (AHA), the World Health Organization (WHO), and others, I put together this list of facts about your protein intake.
This list of 51 things to know about your protein intake; broken down into The Basics (1-6), Protein and Your Diet (7-13), The Details (14-28), Facts for Athletes (29-37), and Global Health & Chronic Diseases (38-51).
Protein Intake: The Basics
1. Protein is one of the three macronutrients key to a well-balanced diet
Your caloric intake is generally broken down at a high level into three categories, or “macronutrients.” These include proteins, carbohydrates, and fats. All three are generally regarded as part of a well-balanced diet.
2. Protein intake should generally constitute somewhere between 10 - 35% of your caloric intake
While the World Health Organization (WHO) suggests protein intake should constitute 10-15% of your caloric intake, the CDC and the Institute of Medicine have established an Acceptable Macronutrient Distribution Ranges of 10-35% for adults aged 19 and older, 10-30% for children aged 4-18, and 5-20% for children under 4. However, some modern diets challenge this (more on this, later).
3. Individual recommended protein intake suggestions depend on your body weight
Another guideline for recommended dietary protein intake is 0.8 grams of protein per kilogram of body weight (0.36 grams per pound).
4. Men and women have the same protein intake requirements
According to the USDA guidelines, the percentage of calories from your diet derived from protein do not differ between men and women. However, women typically require fewer calories than men. So while the percentage may be the same, the overall quantity of protein consumed will be less for women than it is for men.
5. The nutrition label “Protein” does not constitute just one thing
As mentioned in fact #1, protein is a term to describe one of the three macronutrients. You may know that fats and carbohydrates are also broad terms that include specific subcategories like omega-3 fatty acids or sugars. Proteins work the same way. Proteins can be broken down into amino acids. We’ll go into more detail on these, later.
6. Most Americans consume an adequate amount of protein
According to the CDC, the diet of American men and women averages 16% and 15.5% protein, respectively. This falls in line with the National Academy of Medicine’s recommendations. This also aligns well with NHANES data. Check out our interactive charts to learn more about the average American’s dietary patterns with respect to macronutrients and micronutrients!
Protein and Your Diet
7. Protein, in and of itself, will not cause weight loss
The USDA and the Department of Health and Human Services maintains that “strong evidence shows that there is no optimal proportion of macronutrients that can facilitate weight loss or assist with maintaining weight loss.” Diets with different proportions have all demonstrated weight loss and weight gain - the critical component is still total caloric intake. But, protein may still help…
8. Protein produces higher satiety than carbs and fats
High satiety for certain proteins means you feel fuller after eating them. So while proteins themselves don’t cause weight loss, a diet rich in protein may help you lose weight by helping you feel full, and thus, consume fewer calories.
9. Increased protein intake during caloric restriction may help maintain muscle during weight loss
Those looking to lose weight may experience an unfortunate side effect when they succeed - their muscle mass declines along with the fat! In order to maintain muscle mass during weight loss - particularly important for the elderly to maintain mobility and prevent falls - studies show that maintaining a relatively high protein intake can help.
10. The ketogenic diet, high in fat, is also higher in protein than the typical Western diet
The standard ketogenic diet recommends that 20% of your caloric intake comes from protein, while the high protein ketogenic diet recommends 35%. The rest? Primarily fats.
11. Vegans and vegetarians typically consume less protein
A comparison of restricted diets showed vegetarians had less protein intake than omnivores, and vegans even less so. Nevertheless, their protein intake levels were still within a healthy range.
12. Diets from the Blue Zones span a wide range of protein sources and quantities
The Blue Zones harbor some of the healthiest and long-lived individuals in the world, so their diets are worth investigating. Their diets vary quite a bit, but they all fall within the recommended range for protein intake of 10-35%. Based off of research from the Blue Zones Solution, the breakdown of the percentage of calories derived from protein is as follows:
Okinawa, Japan: 10%
Ikaria, Greece: 17%
Nicoya Peninsula, Costa Rica: 25%
Loma Linda California, USA: 28%
Sardinia, Italy: 32%
13. Blue Zones diets do not contain much meat
Despite eating more protein than the average American, their protein source is largely derived from non-meat products. The breakdown of their caloric intake derived from meat is as follows:
Okinawa, Japan: 2%
Ikaria, Greece: 5%
Nicoya Peninsula, Costa Rica: 5%
Loma Linda California, USA: 4%
Sardinia, Italy: 5%
Protein Intake: The Details
14. Nine essential amino acids must be obtained from your diet
There are 20 standard dietary amino acids. The body degrades and resynthesizes proteins continuously throughout the day. But this process is not perfectly efficient. Some are lost, so they must be replaced. Sometimes termed indispensable amino acids, these 9 amino acids cannot be produced from other molecular precursors in the body. What does that mean? The only way to make sure your body has them is to eat them!
15. Protein Quality is a term that better describes some of these aspects of adequate dietary protein intake
The quality of protein is more important than simply the number of grams of protein in your food. The Food and Agriculture Organization of the UN and the World Health Organization describe how this essentially comes down to the digestibility of the protein (how well your body can actually absorb and use the protein you eat), and the amino acid composition (how complete the protein is to meet your health needs).
16. The nutrition label “Protein” does take protein quality into account
The FDA’s labeling protocols stipulate that the protein quantity on nutrition labels take into account both the amino acid profile and its digestibility to give, more or less, a measure of nutritionally available, quality protein.
17. Meat is a complete protein
Meat, by and large, has all of the amino acids necessary for dietary health in digestible forms.
18. Protein in vegetables are generally less digestible
This means that although a vegetable might contain a decent amount of protein, your body might not be able to efficiently digest it all, and therefore not use it all. But this is very much vegetable-dependent and nutrient-dependent.
19. Vegetables tend not to contain all essential amino acids either
And because plants typically lack appreciably digestible amounts of one or more amino acids, the Institute of Medicine classifies them as incomplete proteins.