Q: When eating vegetarian meals, is it important to choose food combinations that provide complementary protein?
A: You are referring to the fact that most plant foods have incomplete protein, meaning they are low in one or more of the essential amino acids that we need to form muscle and other body tissues, enzymes, hormones and more. Amino acids are the building blocks that make up protein. For example, rice and beans each supply amino acids that are low in the other. In the past, it was thought that these needed to be eaten at the same meal for the body to use the amino acids. Now studies show that the body can get needed amino acids from protein eaten throughout the same day.
Different types of plant foods vary in amino acid content. That’s why it is important, especially if you are eating primarily vegetarian meals, to get a variety of protein sources. For example, grains, nuts and vegetables might not be able to meet needs for the amino acid called lysine without the help of legumes (dried beans and peas). If you eat a variety of whole grains, legumes (dried beans and peas), seeds, nuts and vegetables throughout the day, and in amounts that meet your calorie needs, you should meet protein and amino acid needs without focusing on creating specific combinations in each meal.
Karen Collins, MS, RDN, CDN, FAND
American Institute for Cancer Research
The American Institute for Cancer Research (AICR) is the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the scientific literature and educates the public about the results. It has contributed over $100 million for innovative research conducted at universities, hospitals and research centers across the country. AICR has published two landmark reports that interpret the accumulated research in the field, and is committed to a process of continuous review. AICR also provides a wide range of educational programs to help millions of Americans learn to make dietary changes for lower cancer risk. Its award-winning New American Plate program is presented in brochures, seminars and on its website, http://www.aicr.org. AICR is a member of the World Cancer Research Fund International.