Is a High Protein Diet Safe? An Evidence Based Answer

A high protein diet is NOT biocompatible with human physiology.

This post will address some common questions I get around protein from clients and students. One of my primary goals when teaching about nutrition is to help people understand that there are really incredible, highly usable sources of protein in plants!

Let’s first establish a foundation for the main point of this post.

Protein is made up of amino acids.  There are both endogenous and exogenous sources. This means that of course, you get some protein through the food that you consume (exogenous), but your body also makes proteins (endogenous). In fact, the average person actually makes as much or more protein than they would typically consume.¹  Your body is amazing!

Many people use the term protein synonymously with meat. Although meat normally is considered a protein source, they are not one and the same.  There are also lots of plant sources of protein such as beans, lentils, nuts, seeds, quinoa, and even broccoli (to name a few).

All nutrients are important. Protein isn’t in itself bad or good (nor are carbs or fats for that matter); However, too much (or even an important thing) can cause many challenges. Although it’s rare for most people, you can even get too much water. Many nutrients are dose-dependent, so too much or not enough has a domino effect of potential issues in the body. Protein is no exception.

Also, it’s important to note that protein deficiency is rare in the US. The standard American diet is overloaded with protein. A lack of protein should not be a concern for the vast majority of the population.

A high protein diet is defined as a diet where 20% or more of your daily caloric intake is coming from protein.  The standard American diet is normally at least 15% or higher.¹

So what’s the problem?  A high protein diet is strongly associated with:

1. Weight gain² and obesity³
2. Cardiovascular disease⁴
3. Cancer⁵⁶
4. Kidney disease⁷
5. Morbidity⁸

What about plant vs. animal sources of protein?  Is a protein a protein?  In other words, if we are comparing 20 grams of protein from beans to 20 grams of protein from chicken, are we even looking at comparable substances in terms of the energy that they can produce in the human body?  That depends on several factors, but one important point is the nutrient density comparison.  Although both sources may have the same number of grams, plant sources more often have more micronutrients and phytochemicals.  Also, meat has NO fiber so it will not help the microbiome like plant sources will. Although it’s not the purpose of this post, the microbiome has multiple implications on weight loss and overall health.⁹

It is clear from the research that animal proteins (as opposed to plant proteins) are associated with many causes of morbidity.¹⁰  So it’s not just about what it doesn’t have (i.e. fiber) but also about what it does have: more saturated fat,¹¹ bacteria, and other pathogens.¹²  In other words, even if you can get the same amount of protein from meat, is it worth the risk?  I don’t think so.

The RDA (recommended daily allowance) for protein is about .4 grams/lb of body weight. This means that on average a woman will need about 46 grams and a man will need around 56 grams. Of course, these are averages and may need to be adjusted a bit for immune stress, activity level, and if pregnant or nursing. Also, note, the amount that you should be getting is based on your ideal/healthy body weight, not your current weight. This can be helpful for achieving your ideal body weight, regardless of if you need to gain or lose pounds.

Although it is true that there are some populations that need a bit more protein, such as athletes, pregnant and nursing mothers, etc., those populations also need more calories. So assuming their proportions of macronutrients are balanced with a primarily whole food plant diet, they just need to eat more food to get a bit more of everything that they need.¹³

We live in a culture that is so fear-based in so many ways. I hear people all the time asking about protein. They are “afraid they will become deficient.”  If you’re eating a junk food diet, you’re likely to have issues with every nutrient, not just protein. But if you stick with an incredible, delicious, whole food plant-based diet, organic and properly prepared, you will be safe and overly protected from disease deficiencies of most kinds.

If you feel like you’re doing all you can and not getting the results you want, we are here to help.  You can check out our natural health tips on social media or, if you’re ready to really make changes, call the clinic to schedule your life-changing consultation.  269-204-6525

Reference List:

1. Stipanuk MH, Caudill MA. Biochemical, Physiological and Molecular Aspects of Human Nutrition. Fourth. Elsevier; 2019.
2. Hernández-Alonso P, Salas-Salvadó J, Ruiz-Canela M, et al. High dietary protein intake is associated with increased body weight and total death risk. Clin Nutr. 2016. doi:10.1016/j.clnu.2015.03.016
3. Smith GI, Yoshino J, Kelly SC, et al. High-Protein Intake during Weight Loss Therapy Eliminates the Weight-Loss-Induced Improvement in Insulin Action in Obese Postmenopausal Women. Cell Rep. 2016. doi:10.1016/j.celrep.2016.09.047
4. Virtanen HEK, Voutilainen S, Koskinen TT, Mursu J, Tuomainen T-P, Virtanen JK. Intake of Different Dietary Proteins and Risk of Heart Failure in Men. Circ Hear Fail. 2018. doi:10.1161/circheartfailure.117.004531
5. Fontana L, Klein S, Holloszy JO. Long-term low-protein, low-calorie diet, and endurance exercise modulate metabolic factors associated with cancer risk. Am J Clin Nutr. 2006. doi:10.1093/ajcn/84.6.1456
6. Sourbeer KN, Howard LE, Andriole GL, Moreira DM, Freedland SJ, Vidal AC. PD31-01 METABOLIC SYNDROME COMPONENTS AND PROSTATE CANCER RISK: RESULTS FROM THE REDUCE STUDY. J Urol. 2014. doi:10.1016/j.juro.2014.02.2260
7. Kalantar-Zadeh K, Kramer HM, Fouque D. High-protein diet is bad for kidney health: unleashing the taboo. Nephrol Dial Transplant. 2020. doi:10.1093/ndt/gfz216
8. Trichopoulou A, Psaltopoulou T, Orfanos P, Hsieh CC, Trichopoulos D. Low-carbohydrate-high-protein diet and long-term survival in a general population cohort. Eur J Clin Nutr. 2007. doi:10.1038/sj.ejcn.1602557
9. Cullen CM, Aneja KK, Beyhan S, et al. Emerging Priorities for Microbiome Research. Front Microbiol. 2020. doi:10.3389/fmicb.2020.00136
10. Song M, Fung TT, Hu FB, et al. Association of animal and plant protein intake with all-cause and cause-specific mortality. JAMA Intern Med. 2016. doi:10.1001/jamainternmed.2016.4182
11. O’Doherty MG, Cantwell MM, Murray LJ, Anderson LA, Abnet CC. Dietary fat and meat intakes and risk of reflux esophagitis, Barrett’s esophagus and esophageal adenocarcinoma. Int J Cancer. 2011. doi:10.1002/ijc.26108
12. Rouger A, Tresse O, Zagorec M. Bacterial Contaminants of Poultry Meat: Sources, Species, and Dynamics. Microorganisms. 2017. doi:10.3390/microorganisms5030050
13. Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet. 2016. doi:10.1016/j.jand.2016.09.025
14. Feature image by valeria_aksakova from Freepik
15. Photo by Racool_studio from Freepik

Nothing said or implied in this post is intended to treat, cure, diagnose or prevent any disease.  It does not take the place of a qualified health care practitioner and is intended for educational purposes only.