This information is based on personal experiences and general knowledge. It is not professional medical advice. Always consult a healthcare provider before making changes to your diet, lifestyle, or treatment plans. This content was created with the assistance of AI tools to ensure thorough research and readability.
A common concern about vegetarian, vegan, and plant-based diets is whether they provide enough protein. Research shows that a well-planned meatless diet can supply all necessary nutrients, including adequate protein.
Can You Get Enough Protein?
The main question when switching to a plant-based diet is: Can I get enough protein? The answer is a definite yes!
Some people believe that protein only comes from animal products and that without them, protein intake is inadequate. Others think protein is never an issue, no matter the diet. The truth lies between these extremes.
Sources of Plant Protein
Grains, legumes, seeds, nuts, and vegetables are all good sources of protein. Even fruits contain small amounts of protein. Therefore, plant-based diets can easily meet and often exceed the recommended protein intake. However, in parts of the world with limited food variety, protein deficiency can be a problem.
When Protein Intake May Be Low
Protein can be insufficient if a diet is mainly fruit (as in some raw vegan diets), very low in calories (such as with anorexia or loss of appetite), or contains too many processed or junk foods (which can also be vegan). Minimal consumption of legumes and nuts can also lead to low protein. Older adults and athletes often require more protein than average.
Signs of Protein Deficiency
Physical signs include swelling caused by fluid retention, increased infections, muscle wasting, and higher risk of bone fractures, especially in seniors. Severe deficiency can lead to skin problems, brittle nails, fragile hair, and hair loss. In infants and children, growth may be stunted. Mild protein shortages may increase appetite and contribute to obesity, while severe shortages reduce appetite. Blood tests measuring serum albumin can indicate protein deficiency.
How Much Protein Do People Typically Get?
In the United States, the average adult consumes about 88 grams of protein daily, which is 14-16% of total calories. For a man weighing 154 pounds (70 kilograms), this exceeds the recommended dietary allowance (RDA) by 25-30%. For a woman weighing 127 pounds (58 kilograms), this is almost twice the RDA.
Most Americans get about two-thirds of their protein from animal sources. Studies in the UK, France, and North America show protein intakes vary by diet type. However, the Adventist Health Study-2 found similar protein intake among health-conscious groups, regardless of whether they ate meat.
Plant vs. Animal Protein for Strength and Bone Health
A recent study showed no difference in strength among athletes consuming 1.6 grams of protein per kilogram of body weight (twice the RDA), whether from plant sources like soy or animal sources like whey protein.
The Adventist Health Study-2 also found no difference in bone fracture risk or bone strength among men with different diets, and no difference for women, as long as calcium and vitamin D intake were sufficient.
Can You Eat Too Much Protein?
The liver breaks down extra protein by removing nitrogen, which becomes ammonia and then urea, excreted by the kidneys. Some nitrogen supports hair, skin, and nails. Very high protein intake—often from excess meat or protein supplements—can strain organs and increase risks for chronic diseases.
Research reviewing 32 studies linked excessive protein with:
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Liver stress, shown by high liver enzymes and albumin in blood
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Kidney issues, including increased urea and risk of kidney stones
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Higher risk of colon and other cancers, especially from red meat
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Progression of cardiovascular disease
Such excessive protein intake is not seen in adults eating varied whole-food, plant-based diets.
Protein Intake by Country and Diet Type
Meat Eaters
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EPIC-Oxford (UK): 90 grams protein, 17.2% of calories
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Nutrient-Santé (France): 84 grams protein, 17.6% of calories
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AHS-2 (US & Canada): 74.7 grams protein, 14.7% of calories
People Between Meat Eaters and Vegans
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EPIC-Oxford (UK):
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Lacto-ovo vegetarians: 70 grams, 14% calories
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Fish eaters: 79 grams, 15.5% calories
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Nutrient-Santé (France): 64 grams, 14.2% calories
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AHS-2 (US & Canada):
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Lacto-ovo vegetarians: 70.6 grams, 13.7% calories
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Fish eaters: 72.7 grams, 14.2% calories
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Vegans
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EPIC-Oxford (UK): 64 grams protein, 13.1% of calories
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Nutrient-Santé (France): 60 grams protein, 12.8% of calories
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AHS-2 (US & Canada): 70.7 grams protein, 14.4% of calories
The Bottom Line
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Most adults in Western countries, including vegans, consume more than enough protein.
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Plant proteins support strength and bone health just as well as animal proteins when intake is adequate.
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Most Americans exceed the protein RDA.
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Excessive protein intake, often from animal sources or supplements, can strain organs and raise chronic disease risks.
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Whole-food, plant-based diets do not tend to result in excessive protein consumption.
Research
- Plant-Powered Protein: Nutrition Essentials and Dietary Guidelines for All Ages by guest authors Brenda Davis, RD; Vesanto Melina, MS, RD; and Cory Davis, MBA
- Personal Knowledge
