Because research has shown that a vegetarian or vegan diet may have health benefits for people living with cancer, some survivors decide to embrace a meat-free lifestyle. If you or a loved one has made this decision–because of a cancer diagnosis or for other health or ethical reasons–you may be wondering how to get enough protein.
When vegetarian and vegan diets started becoming popular, there was widespread concern that people excluding meat from their diet would lack protein and other important nutrients. Pairing complementary proteins–the idea that you need to eat beans with rice, for instance, in order to form a complete protein that meets your body’s needs–was seen as a solution, and many still follow this advice.
But do vegetarians really need to eat specific combinations of food in order to get enough protein?
The simple answer: no. As long as you eat a wide variety of whole, natural foods, you don’t need to worry about pairing certain foods together. Your body does a good job of holding onto nutrients you get from one type of food and combining them with nutrients from other foods, as needed.
Let’s get into the less simple answer:
Our bodies use amino acids to make protein. We make some amino acids naturally in our body—these are called non-essential amino acids. There are other amino acids, called essential amino acids, that we must get from the food we eat.
There are many types of essential amino acids, and our bodies need all of them to make protein. When a food contains all the essential amino acids, it is considered a complete protein.
Complete sources of protein:
- Milk, yogurt, cheese
- Meat: beef, pork, poultry, fish, seafood, and eggs
- Soy, like tofu and edamame
A food that does not contain all the essential amino acids is called an incomplete protein.
Incomplete sources of protein:
- Most grains like wheat and rice
- Nuts (almonds, cashews, pistachios, etc.)
- Beans (lentils, chickpeas, navy, pinto, black beans, etc.)
Previously, many people believed that incomplete proteins had to be consumed in pairs that complemented each other in order for our bodies to use the amino acids and make a complete protein. The general rule of thumb was that grains, nuts, and seeds needed to be eaten in the same meal as beans/legumes to form complete proteins (i.e. beans with rice).
While it’s true that those combinations form complete proteins, we now know that we don’t have to eat them at the same time in order to get protein. Our bodies store amino acids until we need them. If you have beans for lunch, your body will hold onto some of those amino acids until you eat rice at dinner, when it can form a complete protein. So, chances are good that if you eat a variety of both complete and incomplete proteins throughout the day (and overall in your diet), you’re getting all the amino acids you need!
Meghan Perkins is Project Angel Heart’s registered dietitian. After a semester studying baking and pastry arts at culinary school, Meghan quickly found her passion for clinical nutrition and transferred to the University of Northern Colorado to earn her bachelor’s degree in dietetics. Meghan has worked in clinical and private practice settings, educating patients about how their food choices impact their health with an emphasis on CKD, diabetes, heart disease, celiac disease, and weight management. In her free time, Meghan enjoys exploring Denver by bike with her husband, trying new coffee and tea shops, hiking in Crested Butte, and relaxing with her dog Barney.