When you become vegan or vegetarian, suddenly everyone becomes all concerned about your protein intake. With frenetic intensity they ask, “But where do you get your protein?” And though they seem to genuinely want to know, they’re already skeptical of the answer before they’ve even heard it.
That’s because our culture’s beliefs about animal-based proteins are so deeply entrenched that to go against them is nothing short of blasphemy. But the thing is, those beliefs are based on myths, misinformation, and lies.
The myths about protein
Take a look at the most pervasive beliefs about meat and protein:
- Protein is only found in animal products like meat, eggs, and dairy.
- You need to eat meat (a lot of it) to build muscle mass, and you need lots of protein to slim down.
- Protein keeps you fuller longer.
- The more protein in your diet the better.
And while there is plenty of testimonial and anecdotal evidence to back these claims, the most complete and un-biased research (read: the studies not commissioned by the meat industry) proves them all to be false. Let’s look at the claims one by one, paired with the truth about protein — including the facts about how much you protein you really need.
The truth: What you need to know about protein
First things first: Animal-based foods are not the only place to find protein — all plant-based foods contain protein. “Research has shown that all plants contain protein and at least 14% of the total calories of every plant are protein,” writes Dr. Scott Stoll, a board-certified specialist in physical medicine and rehabilitation. Vegetables, beans, grains, nuts, seeds, and even fruit all contain protein, and some more than others. For example: 1 cup of broccoli has about 2.5 grams of protein, 1 cup of brown rice has 5 grams, 1 cup of edamame has 17 grams, and 1 cup of quinoa has 24 grams of protein.
The idea that meat is the best source of protein is simply a myth. “Some people say that eggs, cow’s milk, meat, and fish are high-quality protein,” writes Dr. Reed Mangels for the Vegetarian Resource Group. “This means that they have large amounts of all the essential amino acids.” But we actually have a biological requirement for amino acids, he says, not for protein — and there are plenty of plant sources that can give you all the amino acids you need, plus all the micronutrients found in nature’s finest foods without the fat and cholesterol of animal products. “Soybeans, quinoa (a grain), and spinach also are considered high-quality protein,” Mangels offers as an example, and “other protein sources of non-animal origin usually have all of the essential amino acids.”
While it’s true that protein can help build mass, it’s not necessarily lean or — even muscle. Consuming a diet high in animal proteins has shown to cause weight gain and cancer, among other things. That’s because protein stimulates growth hormones, especially if it’s from an animal source — and those hormones don’t discriminate. This is one of the central points of the groundbreaking work “The China Study,” the largest comprehensive study of human nutrition ever conducted, according to wellandgood.com. A host of studies conducted since the book’s publication have confirmed that diets high in animal protein raise cancer risk and that people who live on these diets are more likely to die early for a number of reasons, according to LiveScience. But meat isn’t the only protein to blame: cow’s milk does its share of damage on the human body: “In multiple, peer-reviewed animal studies, researchers discovered that they could actually turn the growth of cancer cells on and off by raising and lowering doses of casein, the main protein found in cow’s milk,” reports wellandgood.com. And in case you’re still not convinced that plant-based protein is superior to animal-based, remember this: “The link between high-protein intake and risk of cancer almost vanished when the researchers considered participants whose protein mainly came from plants, such as beans,” LiveScience reports.
If you’re looking for a snack to tide you over longer, guess what: protein isn’t what keeps you full. It’s one of those things that’s been repeated so often that it’s taken as fact, though it’s actually only partially true. Sure, protein can help keep the hunger at bay, but not by itself. “When protein and fiber are eaten together, they are digested more slowly than when eaten alone or as compared to a meal consisting of simple carbohydrates,” writes Michele Borboa, MS, for SheKnows.com. In fact, you could leave protein out of this and give all the credit to fiber. “High-fiber foods also tend to contain more nutrients and fewer calories, are digested more slowly, and help us feel full sooner,” according to Elaine Magee, MPH, RD, for WebMD. Another reason, according to the Mayo Clinic: “High-fiber foods generally require more chewing time, which gives your body time to register when you’re no longer hungry, so you’re less likely to overeat. Also, a high-fiber diet tends to make a meal feel larger and linger longer, so you stay full for a greater amount of time.” And just so you know: Fiber is only found in plant-based foods. There is none in animal products.
So you now know that more is not better when it comes to protein. In fact, getting too much protein is actually dangerous. “Just because our bodies have a vital need for a substance does not mean that twice or three times our need is even better. In the case of protein, the concept that more is better is dead wrong,” writes Alan Goldhamer, D.C., founder of the TrueNorth Health Clinic. On an extreme level, consuming too much protein can lead to protein toxicity, which causes kidney failure and eventual death. But those who have a high-protein diet are more likely to suffer from more mainstream maladies: Eating too much protein has been shown to cause disease and sickness throughout the entire body, like kidney disease, cancer, osteoporosis, autoimmune diseases, candidiasis (yeast overgrowth), hypersensitivity issues, and disorders caused by chronic inflammation. And, as previously discussed, it makes you fat. “It is ironic,” Goldhamer concludes, “that the chief argument used to promote the use of animal products — that is, the purported need for large quantities of protein — is the greatest reason for avoiding them.”
how much protein do we need?
The thing is, most Americans are not getting too little protein, they’re getting way too much — yes, even the vegans, who consume no animal products at all. Which begs the question, how much protein do we really need?
It’s a tough question to answer because every expert seems to have a different opinion — and pretty much all of those beliefs are backed by science. In my studies I’ve read recommendations ranging from 10 percent of your daily total calories to 40 percent. This could mean anywhere from 50 grams a day to almost 200 grams, which is a huge difference.
The only way I’ve found to answer that question with surety is to pose another question: How does your diet make you feel? If you’re not eating enough protein, you may notice a decrease in muscle mass or definition, muscle weakness and fatigue, hair loss, irritability and mood swings, anemia, skin changes, and water retention. If you’re getting too much protein, on the other hand, you’re likely to experience weight gain, dehydration, high cholesterol, and even more serious effects like kidney disease or dysfunction, kidney stones, reduced liver and brain function, and cancer.
While neither situation is ideal, it’s clear that the risks of consuming too much protein are far more grave than consuming too little. So let’s take a look at the lower protein recommendation.
Many experts on the whole-food, plant-based diet recommend that 10 percent of your daily calories should come from protein. Accordingly, they also recommend that 80 percent of your calories should come from carbohydrates and the final 10 percent from healthy fats. So how much is that exactly? Let’s look at the formula.
First, convert your weight into kilograms. You can quickly do that by dividing your weight in pounds by 2.2. Next, multiply the number of kilograms by 0.8. That’s how many grams of protein you need in a day. For example, if you weigh 150 lbs., you need about 55 grams of protein per day. Here’s a quick look at protein intakes for various weights:
It’s important to note, however, that if you are extremely active and/or a body builder or pregnant, your protein needs will be increased. Andy Bellatti, M.S., R.D.N., recommends multiplying your weight in kilograms by 1.2 or 1.3 (all the way up to 1.5) for these special situations, but please consult a qualified professional for advice on your personal needs.
What does that look like in terms of real food?
- A cup of oatmeal cooked in soy milk with an ounce of walnuts on top has about 20 grams of protein.
- A green smoothie with kale, chia seeds, flax seeds, 1 carrot, 1 banana, and a handful of blueberries has about 10 grams of protein.
- A spinach salad with tomatoes, and yellow pepper has 5 grams of protein.
- Vegetable stir-fry with carrots, snow peas, broccoli, bok choy, bean sprouts, edamame, and cashews on a bed of brown rice has 30 grams of protein.
If this is what you ate in a day, all these plant-based foods would combine to give you a total of 65 grams of protein — easily meeting the daily recommendations and even exceeding for some people.
While it can be nice to have a concrete number to make us feel that we’re on track and in control, most experts advise against holding to a figure and keeping rigid track. They argue that it’s this kind of rigid, checklist mentality that makes people fear food and gives it power over them. If you’re getting enough calories, they say, you don’t need to keep track. You’ll easily get enough protein.
The final word
If you’re considering going plant-based or even just trying to add more veggies and whole grains into your diet, you can let go of the fear of not getting enough protein or coming up nutritionally deficient. In fact, a plant-based diet not only gives you enough protein without having to think about it, it gives you good quality components bundled with other healthful components found only in plants, like fiber and a dazzling array of vitamins, minerals, and micronutrients. A plant-based diet gives you everything your body needs to thrive — and in abundance! — without the unhealthy and downright dangerous side effects of a diet too full of animal-based proteins and fats.
For more information, you can read this post on protein from the U.C. Davis Integrative Medicine program, this collection of articles and blog posts on protein from the T. Colin Campbell Center for Nutrition Studies at Cornell, and any of the articles linked to in this piece.