Do vegans get enough protein?

One most common questions I get about the vegan diet is about protein. “If I don’t eat meat or dairy can I get enough protein?” “Can I still build muscle on a vegan diet?” “Without animal protein will I have enough energy?” The answer to these questions is unequivocally: YES!

If you want to skip the details that follow, here’s the main point:

If you eat a well-balanced vegan diet (i.e. eat stuff besides just grains) don’t worry about getting enough protein or calculating your protein needs, even if you are an athlete.

Now for the explanation:

There is an excellent article on this topic by Reed Mangels, Ph.D., R.D., on this topic here: “Protein in the Vegan Diet”

In this article, Dr. Mangels suggests 10% of total daily calories from protein is required for a healthy adult. Using the same sources, I argue that the amount we need is as low as 8%. I’d also like to put some of the foods required to meet this requirement in a Chinese context.

The Institute of Medicine’s Food and Nutrition Board (FNB) publishes the standard nutrition requirements for the United States. The most updated information is in the 2005, “Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients).”

The FNB represents the establishment and is rather conservative in its recommendations. For both men and women, they’ve set the Recommended Daily Allowance (RDA) at .80 grams of protein per kg of body weight per day. The World Health Organization also publishes similar data for worldwide population recommendations. They arrived at an RDA of .83g per kg of bodyweight per day, fairly similar to the FNB requirements. ¹ This breaks down to about 10% of calories as protein. Dr. Mangels follows the FNB guideline when making dietary recommendations in his article.

However, a more precise measure for protein intake is the Estimated Allowed Recommendation (EAR), which the FNB sets at .66 g protein/kg/day (about 8% of calories from protein). The EAR for any given nutrient reports the need for a statistically average person, whereas the RDA is set roughly 2 standard deviations (or, exactly 1.24 times) higher than the EAR. This means the RDA meets or exceeds the requirements of 97.5% of the population.

The Institute of Medicine has argued in the past that nutrient labels on food (the ones that show you how much of your daily nutrition you get from a serving) should be based on the EAR instead of the RDA. However, the US Food and Drug Administration (FDA) uses RDA values assuming that most people will undershoot the recommendations in planning meals. In the US ² and in China ³, we consume far above the conservative recommendation 10% of calories from proteins. Vegans eat less protein than omnivores, but still get more than enough. ⁴

Another point made in the IOM report: the human body recycles both essential and non-essential amino acids at a rate of about 90% in diets devoid of protein. So if for some reason you hit below the mark on the RDA or EAR once in a while, you should be just fine.

*In determining daily calorie needs, assumed a man and woman who get moderate exercise 5 days a week.
Calorie Calculator

Grams into Food

So how much is 38 or 48 grams of protein? It’s actually much easier to consume than you would think. Take, for example, the menu of a stingy student living in Beijing:

*When cooking oil is included in the menu, it brings down the percentage of protein as share of total calories closer to 10%.

As you can see, even a low-calorie survival diet easily hits the protein requirements for the average 73 kg (160 lbs) man and exceeds those of a 57 kg (125lb) woman. This isn’t the ideal menu, but it illustrates that even when eating simple and cheap vegan food it’s not hard to get enough protein.

As for the white rice on the menu, its often been shunned for being a “simple carb”, but in the case of protein it’s not bad. White rice is 8% protein by energy, exactly the EAR recommended amount. White rice has another surprising advantage that I’ll touch on in a future article.

Perhaps most important to note is, you don’t need to stress out about planning your meals around protein as long as you are eating a well-balanced diet.

Are some proteins better than others?

There is often confusion on the quality of plant versus animal proteins. Protein quality is measured in two ways: (1) How well the nitrogen in the food is absorbed and (2) the presence of essential amino acids.

Animal protein is generally more easily absorbed than say, raw plant protein. Based on this assumption, Dr. Mangels argues vegans should consume more protein than recommended for non-vegetarians:

“Since vegans eat a variety of plant protein sources, somewhere between 0.8 and 1 gram of protein per kilogram would be a protein recommendation for vegans.”

However, once vegetables have been cooked and processed, they are often just as digestible as animal proteins. Because of this, the FNB makes no distinctions in the recommended daily intake for vegetarians:

“Available evidence does not support recommending a separate protein requirement for vegetarians who consume complementary mixtures of plant proteins.” ⁵

In terms of amino acids, most animal proteins include all 8 essential amino acids in sufficient amounts. Plants usually contain all eight but will be relatively low in one or two categories. This is easily remedied by eating different kinds of plants throughout the day to round out your amino acid intake.

Some people assume intuitively that since animal proteins more closely resemble our own bodies that they are a better protein source. However, during the digestive process, all proteins are broken down into their component amino acids. Whether or not the original source contained the right proportions of amino acids is irrelevant. The body can just as easily reassemble amino acids from a variety of plant sources into the proteins you need.

What about athletes?

After reviewing the evidence of the needs of both endurance and resistance athletes, the FNB comes up with the following conclusion:

“In view of the lack of compelling evidence to the contrary, no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise.”

I’ve seen a number floating around on the web that recommends eating 0.5-1.0 gram protein per pound of body weight per day for intense exercise regimes or body building.

To put this in perspective, for a 24 year-old, 5’4’’, 125 lb woman (yours truly) who exercises intensely daily or twice a day, the handy online calorie calculator recommends eating 2248 calories daily. If she ate 1g of protein for every pound of body weight, this would amount to 500 calories as protein, or, a total of 22% of daily calories as protein.

Most recommendations for higher protein I’ve found intake seem to be related to magazines, websites, or “experts” who have an interest in pushing products. Not that we should take all government reports at face value. However, the FNB report recommends a relatively low protein intake recommendation (8-10% of calories) despite connections with companies that produce protein products. ⁶

At the end of the day, for the high-performance athletes, the best strategy might be just to monitor training progress at the margin in response to different protein levels. For most people, moderate exercise for general health or strength building shouldn’t require extra levels of protein.

Protein Consumption in China

As mentioned, the average Chinese citizen, even in rural areas, has long been getting plenty of protein. Demand for animal products indicates that protein consumption will only increase in the coming years.

Real areas of concern in nutrition include anemia, intestinal worms, other micronutrient deficiencies related to poor diet, and obesity.

The demand for more protein could hypothetically add to the burden of nutritional problems among low-income Chinese. The lowest-income urban Chinese and average rural Chinese spend about 47% of their income on food. ⁷ As the demand for meat increases, it drives up the price of staple crops. This harms the groups that spend the most on food and are most sensitive to decreased consumption. Therein lies one of the paradoxes of the “more protein is better” paradigm.

Who is protein deficient?

Protein deficiency does exist, and is fairly common worldwide. ⁸ However, protein-energy malnutrition (PEM) does not exist in isolation. In the developed world where PEM is rare, it is generally secondary to other diseases like AIDS or tuberculosis that interfere with normal protein requirements. Hospitalized patients, elderly people living in homes or who are depressed, and infants ⁹ are other vulnerable populations.

In the developing world, PEM is primarily related to overall food deprivation, rather than inadequate protein intake by itself. ¹⁰ Children living in Asia, Africa, Central America, or the Caribbean who subsist on nutrient- and calorie-poor diets are the most at risk. PEM manifests as two conditions: marasmus and kwashiorkor. Marasmus is a result of starvation in children aged 6-18 mo. Kwashiorkor is usually seen in children weaned too early onto a diet of low-protein starches (such as cassava) ¹¹ , or in children with acute infections. ¹²

If you are eating a well-balanced diet with enough calories, you have no reason to worry about PEM.

Why is everyone so worried about protein then?

There are some nutrient deficiencies vegans need to worry about, in particular iron, B vitamins, and EPA/DHA essential fatty acids. People often confuse protein with these essential nutrients. While nutrient dense foods are often high in protein, it doesn’t necessarily follow that eating more protein will solve micronutrient deficiencies. A varied, plant-based diet not only provides enough protein but can also supply all of the nutrients the body needs. (A more detailed discussion of important micronutrients for vegans available here).

The main source of confusion is the massive industry ($2.7 billion in the US to be exact ¹³) in protein supplements. The sale of protein powders has thrived despite evidence against its necessity, a testament to the power of savvy marketing.  There are protein products tailored for every age and fitness goal. The protein advertising campaign has so thorough penetrated our national psyche that most Americans now regard more protein as the gold standard for planning meals.  China, so it appears, is the next big market for these companies.

Protein powder cannot make you jump higher or run faster. Building muscle is simple: eat more calories ¹⁴, do weight-bearing exercise, and stay healthy by getting enough sleep etc.

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