A whole food plant-based diet provides all the protein you need. This article explains why you don’t have to worry about protein.
How much protein do you need?
The protein requirement for adults is 0.83 grams per kilogram body weight per day. For a person weighing 70 kg, this is about 58 grams. Children and pregnant and breastfeeding women need a little more protein. This is also true for vegetarians and vegans. Vegetarians need 20% more protein. For a person weighing 70 kg, this is about 70 grams. A vegan needs 30% more protein, so a vegan person weighing 70 kg needs about 75.5 grams (1).
What about protein deficiency?
In Western countries, most people consume more protein than they need. People in the Netherlands consume on average 78 grams of protein per day (2). Most people who follow a plant-based diet consume enough protein as well (3). Nevertheless, it’s important to eat a complete and varied diet. Which foods can you eat to get enough protein?
Plant protein vs. animal protein
Good plant sources of protein are bread, grains (such as rice, oats, millet, wheat, spelt, rye), pseudo cereals (such as amaranth, buckwheat, quinoa), legumes (such as lentils, peas, beans, soybeans), nuts, peanuts and seeds. Soy products such as tofu and tempeh are also good sources of protein (4).
Proteins from plants are a bit harder to digest. This is partly because plants contain fibres and cell walls. By processing plant products (for example by cooking or fermenting them) they are more digestible (3, 5).
Essential amino acids
Proteins are made up of 22 different amino acids. Nine of these amino acids are essential. This means your body can’t make them by itself. Plant protein does contain all amino acids, although the proportions in plant foods differ. For example, grains contain a lot of methionine and little lysine. For legumes, it’s the opposite. Therefore, there used to be a recommendation that said to combine grains and legumes in one meal, for example rice and beans. Nowadays, we know you don’t have to combine these foods in the same meal. According to the American Academy of Nutrition and Dietetics, you can get all the essential amino acids when you eat a variety of plant protein sources every day (6). In other words, if you eat grains and legumes regularly, you don’t need to worry about the amino acids.
How to get enough protein?
A good guide to getting enough protein is to have two servings of beans, three servings of whole grains and one serving of nuts every day. A serving of beans is, for example, 130 grams of beans or 60 grams of hummus. A serving of grains could be a slice of bread or 100 grams of cooked grains. And a serving of nuts is about a handful of nuts or nut butter for 1-2 slices of bread. These quantities are also recommended by Dr. Michael Greger, an American doctor who developed a dietary guideline for plant eaters: the “Daily Dozen” (7). How can you apply this in your day to day life?
- Breakfast: oatmeal with fruit, soy milk and some nuts and seeds; or soy yoghurt with cereals, fruit and nuts and seeds.
- Lunch: whole wheat bread with hummus/nut butter; or salad with legumes and grains (for example brown rice or whole wheat pasta).
- Dinner: grains (for example brown rice or whole wheat pasta) with beans and vegetables.
- Soy beans have a high protein quality. That means they are well digestible and have a good proportion of essential amino acids (3). This is one of the reasons why it’s good to use soy products. Some examples are tofu, tempeh and soy drink.
- Quinoa and amaranth have a high protein quality as well (8). These products are called pseudo cereals. They are usually more costly, but you can try if you like them.
Benefits of plant proteins
Getting enough protein is no problem at all if you follow a complete diet with a sufficient amount of grains and legumes. Opting for plant protein sources also has benefits for your health. People who consume more plant proteins have less chance of developing cardiovascular disease (9) and type 2 diabetes (10).
Consequences of too much protein
Many people consume more protein than the recommended amount. In the past, scientists thought that too much protein may lead to osteoporosis and damage to the kidneys. However, this does not appear to be the case when those proteins come from normal food (10, 11). Only people with kidney problems should be careful of eating too much protein (12). However, a high consumption of (animal) protein is associated with a greater risk of developing diabetes (9). Protein consumption increases the production of insulin in the blood (13). The Netherlands Nutrition Centre recommends consuming a maximum of twice the recommended amount of protein (1).
Elderly people and children
For elderly, it is important to pay attention to protein consumption. In Western countries, protein deficiency mainly occurs in the elderly. This is probably because older people often eat less food in general (14). In addition, they are less able to absorb protein within one meal. That is why it is better to take several protein-rich meals per day (15).
Children, on the other hand, get enough or even more than enough protein, even when they eat plant-based. This is shown by research among children aged 1 to 3 years in Germany. However, it appears that children who follow a plant-based diet are smaller and have a lower body weight. The protein recommendations are higher for children than for adults, but children also need more energy. Compared to their body weight, they have to eat relatively more in general (16).
Protein and sports
Athletes often think that they should get a lot of protein. Strength and endurance athletes need 1.5 to a maximum of 2 grams of protein per kilogram of body weight. However, it is not necessary to take protein powders or drinks for that. Because athletes eat more in any case, they already get more protein (1). Taking large amounts of whey protein can potentially damage your liver and kidneys and cause aggression, acne and disruption to the gut bacteria (17).
Research shows that an average of 30 grams of protein per meal is optimal for building muscles. If you take more protein than this in one meal, your muscles cannot use it (14). For building muscle strength and muscle mass, it does not matter whether you get protein from vegetable or animal sources (18).
No worries about protein
When someone asks you questions about protein, you can now explain that you can get enough protein with plant-based nutrition. If you eat a varied plant-based diet, with sufficient grains and legumes, you also get all the essential amino acids. In addition, you can tell that person that vegetable protein sources are healthier than animal sources because they lower the risk of diabetes and cardiovascular disease.
This article was written by Wouter Stap, intern and fourth-year Nutrition and Dietetics student.
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