How much Protein do I need? And what are the best sources?
These are the MOST common questions I get asked!!
Why?
Because marketing and social media sends varying messages and let’s face it… it can be totally confusing!
Here are some MYTHS that are circulating…
You need protein at EVERY meal and…
Animal products (red meat, white meat, seafood, eggs, dairy etc.) are the only and/or superior source of protein.
Plants are either devoid of, low in, or an inferior source of protein.
I’ll explain WHY these are myths... but first, it’s important that you understand…
HOW PROTEIN IS MADE…
Carbon, oxygen, hydrogen and nitrates are needed to make protein. Plants convert carbon, oxygen and hydrogen from water, air and sunlight… Nitrates are taken up from the soil and these are used to build up protein.
Animals eat PLANT matter (i.e. grazing on grass, or being fed grains) and access the PROTEIN and glucose and lipids that are locked in the plant cell wall.
PROTEIN FROM MEAT, SEAFOOD, EGGS AND DAIRY…
Animals CANNOT make protein. All protein originates from plants. Animals take in amino acids (the building blocks of protein) from plants to make muscle tissue. The protein found in animal tissues is recycled plant protein. Animals get their protein from plants.
CAN YOU GET PROTEIN FROM ‘JUST’ PLANTS?
Absolutely!!
You CAN get your protein directly from whole fruit, vegetables, beans, legumes, nuts, seeds and grains… ALL contain protein to varying degrees.
There is a common misconception about PLANTS and PROTEIN, with it being widely believed that plant foods are either devoid of protein or do not have adequate amount, or enough types, of amino acids. The truth is… “In fact, all plant foods contain all 20 dietary amino acids”
WHAT DOES PROTEIN DO?
Protein is a macronutrient, and it is important to include in your diet. It’s the main building blocks of muscles, organs, skin and hair. In addition, proteins regulate your metabolism, support the immune system, plays a role in the formation of blood cells and liver detoxification.
Proteins are made up of individual Amino Acids. When you eat food, and it enters the stomach, gastric juices secreted start to break down proteins followed by the secretion of Pepsinogen when the acidity of the stomach reaches a pH of 2. Pepsinogen’s activity is directly dependent on the pH of the stomach environment. At pH values greater than 2.5, Pepsinogens (then converted to Pepsin) activity begins to decline, with incomplete degradation of proteins. So eating Protein, and the absorption of Protein, are two very different things.
Once the partially broken down protein leaves the stomach, Pancreatic Proteolytic enzymes break down proteins into free amino acids and short chain peptides with 2 to 6 amino acids. These are then transported across the intestinal wall (through a series of actions). The body takes these individual amino acids and reconnects them where necessary in the body (image at end of this section).
There are two types of amino acids:
Non-essential amino acids: Are produced by the body. There are 11 non-essential amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
Essential amino acids: Your body cannot produce these. There are 9 essential amino acids, but adults only need to obtain eight of them: valine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine and tryptophan. The ninth amino acid, histidine, is only essential for infants and is available in breast milk.
By mixing a variety of whole plant-based Protein sources there is absolutely no risk of missing out on any of the 20 amino acids. In fact, plants have a much more beneficial effect on our physiology, not only with Protein but with all important fibre for the Gut Microbiome.
When you eat plants you get Protein PLUS Fibre
which equals a super healthy Gut Microbiome and a super healthy YOU
So how much protein do you need?
While the Recommended Dietary Intake (RDI) of Protein depends on your age, gender and specific health requirements/conditions and physical activity here is a general guide of grams(g) per kilo (kg) of body weight required.
Children … 0-6 mths = 1.43 g/kg. 7-12 mths =1.60 g/kg. 1-3 yrs. = 1.08 g/kg. 4-8 yrs. = 0.91 g/kg.
Males… 9-13 yrs = 0.94 g/kg. 14-18 yrs. = 0.99 g/kg. 19-70 yrs. = 0.84 g/kg. 70+ yrs. = 1.07 g/kg.
Females… 9-13 yrs. = 0.87 g/kg. 14-18 yrs. = 0.77 g/kg. 19-70 yrs. = 0.75 g/kg. 70+ yrs. = 0.94 g/kg.
Pregnancy… 14-18 yrs. =1.02g/kg. 19-50 yrs. = 1.00g/kg.
Lactation… 14-18 yrs. = 1.1g/kg. 19-50 yrs. = 1.1g/kg.
Sports Nutrition: 19-70 yrs = 1.2-1.5 g/kg.
However, with all the Protein ‘hype’, many people are consuming too much protein and with protein being used minimally by the intestinal Microbiota, it can often lead to detrimental health issues.
“Although anaerobic fermentation of fibers is the largest source of SCFAs, acetate, propionate, and butyrate can also be produced from amino acid metabolism. However, less than 1% of the large intestine microbiota uses these metabolic pathways to produce SCFAs”
Excess Protein CANNOT be stored in the body and its elimination can strain the liver and kidneys. There is mounting evidence that excess Protein consumption, especially from animal sources, is linked to certain cancers (i.e.: colon, breast, prostate, pancreas), kidney disease and even osteoporosis.
"Proteins may also be substrates for colonic microbiota, but their fermentation is usually associated with the growth of potential pathogens and the production of undesirable substances"
AND increasing ‘animal’ protein is detrimental to health…
However, from a microbiota perspective, data from animal models indicate that increasing protein intake, especially of animal origin, is associated with induction of dysbiosis, depletion of bacterial taxa producing SCFA and increased production of trimethylamine N-oxide (TMAO), a marker of increased cardiovascular risk"
AND replacing some of your animal proteins with plant based proteins is good for you…
“results indicate that partial replacement of red and processed meats with legume products can potentially change microbiota activity and gut metabolites, suggesting a protective gut metabolic profile against colorectal cancer”
AND reduce your exposure to Persistent Organic Pollutants by including more plants…
“Epidemiological studies indicate an association between intake of certain dietary protein sources and obesity. Different sources of protein such as beans, vegetables, dairy, seafood, and meat differ in amino acid composition. Further, the type and level of other factors, such as fatty acids and persistent organic pollutants (POPs) vary between dietary protein sources. All these factors can modulate the composition of the gut microbiota and may thereby influence their obesogenic properties”
AND if proteins are plant-derived you will have better health outcomes…
“In humans aged 50–65, results from the study of Levine et al. suggest that a high protein intake may be associated with increased overall mortality. However, this was not observed if the proteins were plant derived”
AND reduce animal origin TMAO and reach and maintain a healthy weight…
“The gut microbiota may also convert components from different protein sources into compounds that may be linked to development of disease. Well-known examples are L-carnitine and phosphatidylcholine, present in red meats and egg, which can be metabolized to trimethylamine and trimethylamine oxide (TMAO). In humans, circulating TMAO levels are reported to be associated with increased risk for atherosclerosis development and recently also linked to obesity”
“Proteins derived from seafood, meat, chicken (animal products) contain varying amounts of amino acids, fatty acids, and pollutants, which may interact with the gut microbiota and change the host metabolism, and further impact on obesity development”
AND get stronger bones with plant-based proteins…
“Different sources of dietary protein may have different effects on bone metabolism. Animal foods provide predominantly acid precursors, whereas protein in vegetable foods is accompanied by base precursors not found in animal foods. Imbalance between dietary acid and base precursors leads to a chronic net dietary acid load that may have adverse consequences on bone”
“High consumption of protein from animal origin may be unfavourable, whereas a higher vegetable protein intake may be beneficial for bone health. Our results strengthen the hypothesis that high calcium intake combined with adequate protein intake based on a high ratio of vegetable to animal protein may be protective against osteoporosis”
PROTEIN FROM PLANTS IS A WIN FOR YOUR HEALTH
When you eat a diet rich in fruit, vegetables, whole grains, nuts, seeds, beans and legumes you get all the Protein you need, PLUS a multitude of macro and micro nutrients with an added boost of phytonutrients and antioxidants. Whole food plant-based proteins are pooled by the body throughout the day to form complete proteins. Studies, research and experience show that people thrive on a whole food plant-based diet without having to seek ‘animal sources’ of Protein. There is no such thing as a Protein deficiency in the Western World. However, there is a fibre and nutrient deficiency amongst many individuals!
This table provides some approximations of grams of protein available in whole plant-based foods and also listing animal protein for comparison purposes. There are a lot more but here is a snapshot…
Food, Qty and Protein (Gr)
Beef/Lamb, 100g = 25-28g
Red lentils, 100g = 25g
Green lentils, 100g = 24g
Tahini, 100g = 23g
Chicken, 100g = 22g
Cheese, 100g = 20g
Edamame, 1 cup = 18g
Sesame seeds, 100g = 18g
Fish, 100g = 18-22g
Tempeh, 100g = 13g
Tofu, 100g = 10g
Hemp seeds, 28g = 10g
Amaranth, 1 cup = 9g
Pumpkin seeds, 28g = 8g
Quinoa, 1 cup = 8g
Beans (black, pinto, kidney etc), ½ cup = 7-8g
Wild rice, 1 cup = 6.5g
Egg, 1 large = 6g
Chickpeas, ½ cup = 6g
Almonds, 28g = 6g
Cashews, 28g = 6g
Flaxseeds, 28g = 6g
Chia seeds, 28g = 6g
Buckwheat, 1 cup = 6g
Sunflower seeds, 28g = 5g
Spinach, 1 cup = 5g
Oatmeal, 100g = 5g
Mushrooms, 5 whole = 4g
Brussel sprouts, 1 cup = 4g
Avocado, 1 medium = 4g
Potato, 1 medium = 4g
Corn, ½ cup = 4g
Milk, 100ml = 3.3g
Broccoli, 1 cup = 3g
Rice, 100g = 2.2g
Blackberries/Blueberries, 1 cup = 2g
Sweet potato, 100g = 2g
Cauliflower, 100g = 1.6g
Banana, 1 medium = 1.5g
Cabbage, 100g = 1.3g
So, as you can see, there is no problem getting your Protein needs met from eating a variety of plants every day.
IMPORTANT: Focusing on a single macro-nutrient, to the exclusion of all of the other vitally important nutrients, can lead to an ‘excess or depletion’ of other nutrients which can result in troubling and serious conditions later on.
This is just ONE of the many food strategies (there’s lifestyle ones too) that are proven (by science), that when implemented, WILL ensure you feed your Microbiome… so IT THRIVES… and thus… YOU THRIVE.
I hope this article helps you and your health.
If you want to know more about my programs that are designed to IMPROVE your Gut Health then head HERE or if you want to eat your way back to health — one meal at a time — check out my Gut Health Recipe Compendium. Nat xx
References
Association of Protein Intake with Bone Mineral Density and Bone Mineral Content among Elderly Women: The OSTPRE Fracture Prevention Study. J Nutr Health Aging. 2017.
The relation between dietary protein, calcium and bone health in women: results from the EPIC-Potsdam cohort. 2005.
A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. 2001.
The nutritional value of plant-based diets in relation to human amino acid and protein requirements. 1999.
Egg yolk protein and egg yolk phosvitin inhibit calcium, magnesium, and iron absorptions in rats. 2007.
Maximizing the intersection of human health and the health of the environment with regard to the amount and type of protein produced and consumed in the United States. 2019