Is Too Much Protein Bad for Your Health?
Protein for health
Protein provides many benefits for our health. It helps strengthen our immune system and promotes muscle growth and strength.
Too little protein results in physical weakness, anemia, edema, vascular dysfunction and a weakened immune system. Moreover, once we enter our 40s, we're at a higher risk of developing sarcopenia. Sarcopenia is a loss of muscle tissue and function; even things like walking and daily tasks can become difficult!
And of course, resistance training in concert with adequate protein intake helps us prevent sarcopenia.
How much protein do we need?
This largely depends on our goal, but the current recommended amount for healthy adults who are doing minimal physical activity is 0.8g of protein per kilogram of body weight per day.
For most of us here at Bulk Nutrients (and likely you, too!) to meet the requirements for muscle growth and strength, we're looking at between 1-1.6 of protein per kilogram of body weight per day.
So just how much then? For those performing minimal exercise (1.0 grams), moderate (1.3 grams), and intense (1.6 grams).
Weight loss is of course a different thing entirely. The benefits of weight loss are profound (and beyond the scope of this article) but are very beneficial for optimal health.
An adequate protein intake for weight loss is recommended at 2.3 - 3.1 grams of protein per kilogram of fat-free mass per day.
How much protein is too much?
Research suggests the tolerable limit might be 3.5 grams per kilogram of body weight per day for "well-adapted subjects."
But unless you're at a very low level of body fat, and preparing for a physique show of some kind, you more than likely don't need that much.
Moreover, it seems ~20-25 grams of protein per meal is enough to stimulate muscle growth. But additional research has tested up to 40 grams and found it to be beneficial, but that was more for other tissues in the body. More research here is needed but consuming 30 grams might be a nice happy medium.
But in the real world, we're not sitting at a dinner table worrying about more than 40 grams of protein. What we don't use will be utilised as other energy forms or excreted as waste.
As long as we know that consuming 40 + grams of protein is no better off for muscle growth than maybe 20-25 grams, we're fine!
But again, more work needs to be done here.
Protein and kidney health
Myths have circulated for decades surrounding protein and kidney health. Even today, despite rigorous scientific research, the myth that too much protein harms kidneys still persists.
We might be able to track this myth to a study done in 1928, that fed rats (not humans!) a diet high in protein when they had only one kidney.
And just like that -- the myth was born!
But what happens when we set up a high-protein intake for healthy people?
Well, protein DOESN'T affect kidney function, and specifically, what's called glomerular filtration rate (GFR). GFR refers to a test that deciphers how well the kidneys filter blood and discard waste.
Another study put healthy resistance-trained men on a high protein diet, where they consumed ~2.51 - 3.32 grams of protein per kilogram of body weight per day... for an entire year.
And what did they find? No issues with kidney function!
A review recently in 2019 sifted through the evidence and found something quite eye-opening. The researchers examined protein intake, kidney function, and mortality, and found:
- Low protein intakes of less than 0.8 grams of protein per kilogram of body weight per day, may increase the chance of death.
- Baseline intakes of protein didn't cause kidney function decline
So, what does it all mean? If you're healthy, have no underlying kidney issues (and have two of them), high protein diets shouldn't be a threat to them or your health at all.
And of course, we've got you covered with our Bulk Nutrients WPC options.
The bottom line is that protein is necessary for optimal health. It is great for our immune systems, and for preventing sarcopenia. Protein requirements are anywhere from 0.8 grams to 3.1 grams, depending on how active you are, and what your goal is.
Also, 20-25 grams of protein per meal may be enough to stimulate muscle growth, and up to 40 might be beneficial sometimes, too. A happy medium might be 30 grams, but more research here is needed. Importantly, protein is not harmful to healthy individuals with two functioning kidneys, with that myth stemming from a study in the 20s done on rats, who had only one kidney!
Like many, Dayne was once desperate to lose weight and get into shape. But everyone he asked, everything he read, lead to the same place... nowhere.
His journey started there - researching science journals and completing a Sports Nutrition Specialist qualification so he could make weight loss easier.
More about Dayne HudsonReferences:
- Bilancio, Giancarlo, et al. "Dietary Protein, Kidney Function and Mortality: Review of the Evidence from Epidemiological Studies." Nutrients, vol. 11, no. 1, 2019, p. 196.
- Helms ER, Zinn C, Rowlands DS, Brown SR. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. Int J Sport Nutr Exerc Metab. 2014 Apr;24(2):127-38. doi: 10.1123/ijsnem.2013-0054. Epub 2013 Oct 2. PMID: 24092765.
- Jackson H, Moore OJ. THE EFFECT OF HIGH PROTEIN DIETS ON THE REMAINING KIDNEY OF RATS. J Clin Invest. 1928;5(3):415-425. doi:10.1172/JCI100168
- Jose Antonio, Anya Ellerbroek, Tobin Silver, et al., “A High Protein Diet Has No Harmful Effects: A One-Year Crossover Study in Resistance-Trained Males,” Journal of Nutrition and Metabolism, vol. 2016, Article ID 9104792, 5 pages, 2016. https://www.hindawi.com/journals/jnme/2016/9104792/.
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