Getting Enough Quality Protein

by | Nov 22, 2023 | Article and Issues | 0 comments

That’s the first question I’m asked when people find out I eat a plant-based diet. Understandable, since everyone seems to be talking about high-protein diets, protein shakes, protein bars, and protein powder. Indeed, proteins are a basic and necessary building block for everything that lives.

Have you ever wondered how large, muscular animals like cows, elephants, horses, bison, and giraffes get their protein since they’re all herbivores? You guessed it. The same way I do– by eating plants.

Did you know that all plants have some protein? For example, 1 cup of green peas has 8 grams of protein, spinach 5 grams, and soybeans 11? Think about it—it seems more efficient to me to cut out the “middleman” and get your protein directly from plants. And healthier, too, as plants are higher in fiber, and lower in fat and calories than animal sources.

But vegetables don’t have as much protein per ounce as meat or dairy, so can one get enough protein just by eating plants? According to nutrition experts, the average person needs around 50 grams of protein per day, or 0.35 Grams per pound of body weight. (Certain factors can increase protein needs, however, like extreme stress, trauma, major surgery, burns, and age over 65.) It might surprise you to know that most Americans get way more than they need—averaging 100-120 grams per day— due to high meat and dairy intake.

Let’s look at a sample menu on a plant-based diet:

Breakfast:

  • 1 cup whole oatmeal with raisins, dates, walnuts
  • 1 cup plain soymilk
  • 1 slice whole-wheat toast with plant-based margarine
  • ½ cup berries

Lunch

  • 1 cup lentil soup
  • 1 square corn bread
  • 1 mixed-green salad with vinaigrette dressing
  • ½ cup fresh fruit salad

Dinner

  • 1 cup stir-fried mixed vegetables and tofu with brown sauce
  • 1 cup steamed brown rice
  • Herbal tea

The totals for the day are 1,600 calories and 53 grams of protein. You can see that even with no animal products at all, it’s easy to get all the protein you need.

Now, you might ask, is the quality of plant protein as good as animal protein? Does it have all the essential amino acids my body needs? Early researchers thought we needed to get all the amino acids in one meal in order to make it a “complete” protein. They encouraged vegetarians to be sure to pair say a legume and a grain together. Now we know from more recent studies that isn’t necessary. Eating a variety of whole, unrefined, plant-based foods (nuts, whole grains, seeds, vegetables, legumes) will give you all the essential amino acids you need.

So why is eating animal proteins not recommended? There is a growing stream of evidence suggesting that too much protein may cause or worsen health problems, especially if it comes from animal sources. Here is a partial list:

  • Contributes to increased mortality from heart disease1,2
  • Worsens blood sugar control in people with diabetes3
  • Increases risk of kidney stones4
  • Increases osteoporosis—loss of calcium from bones5,6
  • Reduced bone strength in children7
  • Increases cancer risk8,9,10,11
  • Correlates with increased mortality in those under 65 years old12
  • Increases risk of chronic diseases due to inflammation13

I hope that answers your questions about protein. I’ve included some references so you can read more, or feel free to ask your question in the “ASK DOC” tab.

References:

  1. Marion Tharrey, Francois Mariotti et al., “Patterns of Plant and Animal Protein Intake Are Strongly Associated with Cardiovascular Mortality: The Adventist Health Study-2 Cohort,” International Journal of Epidemiology (April 2, 2018), https://doi.org/10.1093/ije/dyy030 ↩︎
  2. D.M. Ornish, et al., “Can Lifestyle Changes Reverse Coronary Atherosclerosis? The Lifestyle Heart Trial,” The Lancet 336, no. 8708 (July 21, 1990). ↩︎
  3. Effie Viguiliouk, Sarah E. Stewart et al., “Effect of Replacing Animal Protein with Plant Protein on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials,” Nutrients 2015, no. 7: 9804-24, https://doi.org/10.3390/nu7125509 ↩︎
  4. L. Borghi, T. Schianchi et al., “Comparison of Two Diets for the Prevention of Recurrent Stones in Idiopathic Hypercalciuria,” New England Journal of Medicine 346, no.2 (Jan 10, 2002): 77-84. ↩︎
  5. U.S. Barzel, “Excess Dietary Protein Can Adversely Affect Bone,” Journal of Nutrition 128, no. 6 (June 1998): 1051-53. ↩︎
  6. J.E. Kerstetter, M.D. Mitnick et al., “Changes in Bone Turnover in Young Women Consuming Different Levels of Dietary Protein,” Journal of Clinical Endocrinology and Metabolism 84, no. d (1999), 1052-55. ↩︎
  7. Ute Alexy, Thomas Remer et al., “Long-Term Protein Intake and Dietary Potential Renal Acid Load Are Associated with Bone Modeling and Remodeling at the Proximal Radius in Healthy Children,” American Journal of Clinical Nutrition 82 (2005): 1107-14. ↩︎
  8. S.A. Bingham, “Meat or Wheat for the Next Millennium” Plenary lecture. High-Meat Diets and Cancer Risk,” Proceedings of the Nutrition Society 58, no. 2 (1999): 243-48. ↩︎
  9. T. Norat and E. Riboli, “Meat Consumption and Colorectal Cancer: A Review of Epidemiologic Evidence,” Nutrition Reviews 59, no. 2 (2001); 37-47. ↩︎
  10. E. Giovannucci, E. B. Rimm et al, “Intake of Fat, Meat, and Fiber in Relation to Risk of Colon Cancer in Men,” Cancer Research 54, no. 9 (1994): 2390-97. ↩︎
  11. A. Tavani, C. LaVecchia et al, “Red Meat Intake and Cancer Risk: A Study in Italy,” International Journal of Cancer 89, no.2 (2000): 425-28. ↩︎
  12. Morgan E. Levine, Jorge A. Suarez et al., “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,” Cell Metabolism 19 (Mar.4, 2014): 2390-97. ↩︎
  13. P.J. Barnes and M. Karin, “NF-kB: A Pivotal Transcription Factor in Chronic Inflammatory Diseases,” New England Journal of Medicine 10, no. 336 (Apr. 10, 1997): 1066-1071. ↩︎

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