After being out of town for the past week, I made a trip to the grocery store to replenish food for the house. I made my normal routine pass from the fresh vegetables and fruit, to the legumes, and finishing out through the frozen vegetables. While checking out, the young man bagging my groceries commented, "you have the weirdest variety of vegetables." Taking it as a compliment, I responded, "Thank you." After a deep pause, he asked, "So, where do you get your protein from?" I simply pointed to the same vegetables and legumes he was bagging. In the time it took me to pay for my food, he confessed the he thought only meat provided protein, and I encouraged him to go learn more about protein in vegetables (his homework).
This misconception – that we cannot get enough protein from eating a plant-based diet – is sadly common. We have been trained to assume that meat is the only way to get our essential amounts of protein, which is just not true.
The Meat Only Myth
Protein is a major macronutrient we get from food, and is made up of amino acids. These amino acids can generally be categorized as essential and non-essential. The 9 essential amino acids are important, because the body does not make them – rather, we must consume them through our foods. A food that contains all 9, is commonly referred to as a 'complete protein'. Meat contains these essential amino acids, thus there is an assumption (and myth), that meat is the only complete protein.
The Protein Plants
In actuality, many plant-based foods are complete proteins. For example, take a look at the following figure. The BLUE bar is the estimated World Health Organization needs (grams per day) for a 170 lb, healthy and well-nourished person across each of the 9 essential amino acids. The GREEN bars are the values (via USDA) in one of my favorite salads that I make at home: Spinach, kidney beans, fresh broccoli, quinoa, and peas.
Notice that I can get nearly all of my total DAILY need of essential amino acids with ONE MEAL! In some instances, like Tryoptophan and Threonine, I can exceed the daily need in this very tasty salad.
A lot of other plants have all 9 essential amino acids, such as tomatoes, green peppers, corn, lettuce, celery, cucumbers, oats, brown rice, carrots, and pinto beans. The USDA has all this information for you to browse.
By looking at the protein and essential amino acid content in plant-based foods, we must conlude that the belief that we cannot get enough protein by eating vegetables – is a myth. In addition, plant-based foods provide numerous additional nutritional advantages, such as vitamins and minerals. Some have even argued that meat, although a complete protein, can be an 'incomplete vitamin' – not a myth.
Eat your vegetables!