Protein—All There Is To Know | How Much We Need, Plant-Based Sources, High-Protein Diet Risks, The Importance of Amino Acids, Protein Calculators, New Science & More
PROTEIN: WHAT IT IS & WHAT IT DOES
Dietary protein is a macronutrient. (Nutrients are substances needed for growth, energy provision and other body functions. Macronutrients are those nutrients required in large amounts that provide the energy needed to maintain body functions and carry out the activities of daily life. There are 3 macronutrients – carbohydrates, proteins and fats.)
Protein is in every cell in the body. Our bodies need protein from the foods we eat to build and maintain bones, muscles and skin. (source)
Protein provides essential amino acids, which are needed to make muscle, enable the function of vital organs and immune cells, and act as regulatory and transporter molecules.
Adequate essential amino acid consumption is required for optimal physical and physiological function. (Note that the point is amino acid consumption, not protein consumption.)
Amino acids compose protein. When we eat protein, it’s broken down into amino acids.
This point is explained well in the documentary, What The Health.
Amino Acids are stored in a sort of pool in our body that our systems draw from in order to build stuff like muscles, neurotransmitters, and much more. Our body doesn’t store protein; it stores amino acids.
Protein doesn’t equate directly to muscle; it gets broken down and then rebuilt into whatever our body needs most. And, if we’re young, relatively healthy, and relatively active (versus extremely active or pushing our bodies beyond normal or even high performance), our body isn’t building a bunch of muscle simply as a result of eating protein.
Our body doesn’t build stuff out of protein directly.
“You can’t simply increase your muscle mass by eating more protein,” says Bettina Mittendorfer, professor of medicine and nutritional science at the Washington University School of Medicine in St. Louis. “That’s become quite clear.”
“No matter your age, the tried-and-true way to gain muscle is to lift weights or do other strength training.” (source)
Regarding eating enough amino acids or “complete proteins”:
The body does not need all the essential amino acids at each meal, because it can utilize amino acids from recent meals to form complete proteins. If you have enough protein throughout the day, there is no risk of a deficiency. In other words, the recommended nutrient is protein, but what we really need is amino acids.
“Even the National Institutes of Health (a conservative group when it comes to nutrition issues) supports Lappé’s point. On their website, they say that ‘protein foods are no longer described as being “complete proteins’ or ‘incomplete proteins.”‘ So, please, let’s put this issue to rest.” - Grist
Why Don’t We Know This? Aka: Why We Think Protein Is So Important. Aka: Protein Propaganda:
“Protein propaganda” via meat & dairy industry is decades old. (Read: Protein propaganda: It’s what’s for dinner. A good read and part of this Protein Angst series.)
“Protein” isn’t a food (or category of food). It’s a *nutrient. “Everyone knows that “protein” means beans, poultry and fish, as well as meat. But grains and dairy, each with its own sector, are also important protein sources. The meat industry wants you to equate protein with meat. It should be happy with this guide.”
“Protein supplementation is a several-billion-dollar industry supported by strong dogma and heavily promoted. It’s a solidified notion for the recreational and even the professional athlete.” However, there is now “an impressive collection of scientific findings indicating otherwise.” - source
The perception that high protein intake improves muscle mass, muscle function and body weight has led the general public to believe that a high protein intake from consuming naturally protein-rich and protein-enriched foods is ‘healthy’.
Protein is commonly recommended to help people maintain or lose weight because protein is more satiating than carbohydrate and fat, and advertised as lower calorie (though that depends and quality and source or form plays a huge role in health). (See below regarding plant-based versus animal-sourced protein and correlated mortality rates.)
“...to my knowledge no scientific study has ever shown that consumption of protein beyond the RDA-advised minimum (10 percent of daily calories) stimulates additional muscle growth or expedites physiological repair induced by exercise stress.”
(Read more: Slaying the Protein Myth by Rich Roll for Forks Over Knives. And, the study, Dietary Protein and Muscle Mass: Translating Science to Application and Health Benefit via PubMed)
~65% of adults in the USA consider the protein content when buying food or beverages and report ‘trying to eat more protein’.
Most adults in the USA and other developed countries consume substantially more protein than the RDI and PRI and some consume even more than the amount recommended for older adults.
The point about requirements for older adults is important and explained below. “Older” is defined as over 65- 75 years old.
Ask yourself: Why are we obsessed with protein consumption instead of the one food group globally shown to result in a longer, healthier life (fruits & vegetables)? Really, what do you think the answer is? My vote: It’s more “fun” (indulgent) and often easier to eat. Who do you know eating protein because they “have to” but don’t want to? Who do you know that would rather be having some fresh produce instead of protein? Be that person.
HOW MUCH PROTEIN WE NEED
One of the most common questions that I and any/everyone in the plant-based nutrition camp receive. No one seems to know, everybody wants to know, it seems to be all about counting - grams per day, grams per body weight, etc. - and (strong) opinions abound.
I’ve spent the last few years tracking all schools of thought on the topic, testing approaches, coaching hundreds of clients through relationships with protein and am glad to finally be presenting both a lay of the land and a strong recommendation for how much protein you need.
Some advocates of low-to-moderate protein consumption from either mostly or entirely plant-based sources. (These are approaches I highly and often most respect.):
T. Colin Campbell and The China Study, the Hippocrates Health Institute (emphasis on living food), Wendy Green (one of my teachers), the documentaries & resources provided by Forks Over Knives, What The Health, The Game Changers, and related.
THIS STUDY: “Low Protein Intake is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population”
*If you take away only one reference from this entire piece, make it this study.*
General definitions of “high,” “moderate,” and “low” protein diets:
High: 20%+ of daily calories come from protein sources.
Moderate: 10 – 19% of daily calories come from protein. Note: Most Americans are pursuing a moderate to high protein intake with the mindset that this is a healthy or important daily minimum. (See below for what a daily minimum actually is.)
Low: Less than 10% of daily calories from protein.
Minimum daily protein intake (to prevent muscle wasting): 0.6 grams per 2.2 pounds or about 11grams/day. (Or about 1/2 cup of edamame. Or 3 TBSP hemp hearts. That’s IT.)
How to calculate your daily protein intake goals: (note my term “goals” not requirements”)
Considerations: Pounds of body weight *and lean body mass, daily caloric consumption *and actual daily caloric need, level of activity, age, weight or body-composition goals (are you looking to maintain, gain or lose weight):
If you’re athletically competitive or exercising more than once per day, pregnant or breastfeeding, or over age 65 - 75, your daily protein requirement may be 25 - 50% percent higher.
General grams per day recommendations from different schools of thought:
Assuming ~150 lb person, lightly active, not looking to lose any weight, eating 1,800 calories per day.*
*Daily caloric intake is often largely over-estimated in my experience. The higher the quality of calorie, the less we need. I personally practice and regularly observe a decrease in daily caloric intake decrease of up to 40% when people eat more plant-based and high-quality foods.
12% of daily calories (54 grams) - The DRI (Dietary Reference Intake) is 0.36 grams per pound.
14.2% of daily calories (About 64 grams) - Dr. Mercola: You need about one-half gram of protein per pound of lean body mass.
8 - 10% daily calories (40 - 45 grams) - Harvard Medical School (Based on percent of calories for an active adult, about 10% of calories should come from protein.”)
13% - 15% of daily calories (60 - 67.5 grams) - Ben Greenfield’s Perfect Health Diet (20% carbs, 65% fat, and 15% protein)
11% - 21.5% of daily calories (50 - 97 grams) - Vegan protein calculator (for a 150 lb woman, lightly active, looking to maintain weight)
9.7% of daily calories (43.7 grams) - MayoClinic
9.7% of daily calories (44 grams/day) - Weston A. Price
Average Agreement: *12.5% of daily calories should come from protein.
So, if you eat 1,200 calories per day and do not want to change your body composition or weight, that would be 37.5 grams of protein per day.*
*This is not correcting for lean body mass, which would decrease the total.
IMPORTANT PROTEIN INTAKE CALCULATION & PERSPECTIVE POINTS:
Consider it as a percentage of your daily calories, rather than in grams per day. A 120 pound lightly-active person looking to maintain weight will have entirely different needs than a 220 pound very active person looking to lose weight.
Calculate using your lean body mass rather than total body weight for more accuracy. Calculations can also be done using target body weight/mass rather than actual.
Protein is about 4 calories per gram.
Amino acids are king. Remember the importance of amino acids as actually greater than protein. Protein is simply one of the sources of them.
Complete proteins are a myth. (Just google it.)
Plants contain protein (and amino acids). (See “WHERE WE GET PROTEIN” section, below.)
CAUTION AGAINST TOO MUCH PROTEIN
This is a thing. This is the most important “thing” about this whole article.
HEALTH RISKS ASSOCIATED WITH HIGH PROTEIN INTAKE:
75% INCREASE IN OVERALL MORTALITY AND A 4-FOLD INCREASE IN CANCER AND DIABETES MORTALITY DURING AN 18 YEAR FOLLOW UP PERIOD.
These associations were either abolished or attenuated if the source of proteins was plant-based.
Exception: *Over age 65, high protein intake was associated with reduced cancer and overall mortality. // protein intake representing at least 10% of the calories consumed may be necessary after age 65 or possibly 75 to reduce age-dependent weight loss and prevent an excessive loss of IGF-1 and of other important factors
HEALTH RISKS ASSOCIATED WITH MODERATE PROTEIN INTAKE:
ALSO HAD A 3-FOLD HIGHER CANCER MORTALITY (HR: 3.06; 95% CI: 1.49–6.25), THAT WAS MARGINALLY REDUCED WHEN CONTROLLING FOR PERCENT CALORIES FROM ANIMAL PROTEIN.
Previous studies in the U.S. have found that a low-carbohydrate diet is associated with an increase in overall mortality and showed that when such a diet is from animal-based products, the risk of overall, as well as CVD and cancer mortality, is increased even further.
Source above.
Low protein intake during middle age followed by moderate protein consumption in old subjects may optimize healthspan and longevity.
*OVERALL, OUR HUMAN AND ANIMAL STUDIES INDICATE THAT A LOW PROTEIN DIET DURING MIDDLE AGE IS LIKELY TO BE USEFUL FOR THE PREVENTION OF CANCER, OVERALL MORTALITY, AND POSSIBLY DIABETES THROUGH A PROCESS THAT MAY INVOLVE, AT LEAST IN PART, REGULATION OF CIRCULATING IGF-1 AND INSULIN LEVELS.
The detrimental effect of the low protein diet coincides with a time at which weight begins to decline. Weight tends to increase up until age 50–60, at which point it becomes stable before beginning to decline steadily by an average of 0.5% per year for those over age 65.
Source above.
HIGH-PROTEIN DIETS AND CANCER: A TROUBLING LINK …
DIETS THAT ARE HIGH IN ANIMAL PROTEIN CAN BOOST A HORMONE IN THE BODY KNOWN AS INSULIN-LIKE GROWTH FACTOR (IGF-1).
IGF-1 is similar to insulin, and is produced by the liver. It promotes cell growth, which is a good thing in children. But when we become adults, we need lower levels of this hormone, as it’s only necessary to replace old cells that have died off.
Too much IGF-1 in adults stimulates unwanted things — to grow, such as tumors. A report in Cell Metabolism states that “high protein intake is linked to increased cancer, diabetes, and overall mortality.”
IGF-1 also may encourage abnormal cells to break off and move to other areas of the body. In other words, this hormone can encourage cancer to spread once it has developed.
A large study of more than 6,000 adults supports the benefits of a low-protein diet for younger adults. The study found that:
Adults ages 50 to 65 who ate a high-protein diet were 4 times more likely to die of cancer than those who ate a low-protein diet.
Adults ages 50 to 65 who ate a moderate-protein diet were 3 times more likely to die of cancer than the adults on a low-protein diet.
Adults of all ages who ate a high-protein diet were 5 times more likely to die from diabetes
These associations were adjusted for other health factors, including smoking, waist circumference, and other diseases, and they still held true. But, the links were only found when the proteins came from animal foods, not plant sources.
Note that adults over age 65 may benefit from more protein. Older adults who ate high amounts of protein had a 60 percent lower risk of dying from cancer.
Source above
IN AGREEMENT WITH OTHER EPIDEMIOLOGICAL AND ANIMAL STUDIES (ESTRUCH ET AL., 2013; LINOS AND WILLETT, 2007; MICHAUD ET AL., 2001; WILLETT, 2006) FINDINGS SUGGEST THAT: UP TO AGE 65 - 75, THE 0.7 TO 0.8 GRAMS OF PROTEINS/KG (2.2 LBS) OF BODY WEIGHT/DAY SHOULD BE RECOMMENDED (INSTEAD OF THE 1–1.3 G GRAMS OF PROTEINS/KG OF BODY WEIGHT/DAY).
HIGHLIGHTS & RECAP:
High protein intake linked to increased cancer, diabetes, and overall mortality.
High IGF-1 levels increased the relationship between mortality and high protein.
Higher protein diet may be protective for older adults. (Over age 65 - 75, when body weight begins to decline.)
Low protein intake in mice resulted in reduced IGF-1 and tumor progression.
WHERE TO GET PROTEIN (AND AMINO ACIDS) & PLANT-BASED SOURCES OF PROTEIN:
“all 9 essential amino acids are originally synthesized by plants, and are only found in meat and dairy products because animals have eaten those plants.” - source
“As long as you are getting enough calories from a healthy diet, plant foods give you all the amino acids you need, by themselves or in combination with one another.” - source
“ … if you calculate the amount of each essential amino acid provided by unprocessed plant foods, you will find that any single whole natural plant food, or any combination of them, if eaten as one’s sole source of calories for a day, would provide all of the essential amino acids and not just the minimum requirements but far more than the recommended requirements.”
“Modern researchers know that it is virtually impossible to design a calorie-sufficient diet based on unprocessed whole natural plant foods that is deficient in any of the amino acids. (The only possible exception could be a diet based solely on fruit).”
Same: “... the results show that any single one or combination of these plant foods provides amino acid intakes in excess of the recommended requirements. Therefore, a careful look at the founding scientific research and some simple math prove it is impossible to design an amino acid–deficient diet based on the amounts of unprocessed starches and vegetables sufficient to meet the calorie needs of humans. Furthermore, mixing foods to make a complementary amino acid composition is unnecessary.” - American Heart Association journals
Same: “… a careful look at the founding scientific research and some simple math prove it is impossible to design an amino acid–deficient diet based on the amounts of unprocessed starches and vegetables sufficient to meet the calorie needs of humans. Furthermore, mixing foods to make a complementary amino acid composition is unnecessary.” - source
Some sources of plant-based protein:
Spirulina and chlorella (blue-green algae), which are over 60 percent protein // contain all 9 essential amino acids.
1 bunch kale: 9 grams
Hemp protein powder 1 tablespoon has 11 grams of protein.
Cooked quinoa 1 cup (185 grams) has 8 grams of protein. quinoa is a complete protein; it contains all 9 of the essential amino acids
1 oz (2 TBSP) chia seeds: 4.7 grams
1 head cauliflower: 11 - 15grams
Hemp hearts (2 TBSP): 6.3g
1 bunch of broccoli = 17 grams. (Or 2 cups of broccoli = 5g protein)
1 cups spinach (cooked): 5.3g
Green peas: ½ C: 4.3 g
Soybean sprouts: 1 c: 9.2 grams (here we’ve exceed our daily protein needs by 5grams)
1 C brussels, asparagus, : 3 grams
Quinoa or Peas: 8 grams/C
Edamame, Lima beans, regular beans: 15 - 17 grams/C
FURTHER READING & WATCHING:
T. Colin Campbell Center for Nutritional Studies & The China Study
More to be added over time. This is a living article!
