I am somewhat unfamiliar with the concepts of "incomplete" vs. "complete" proteins.  When I was earning my Master's degree in Nutritional Sciences in 1998 we were taught that the concept was no longer valid and we did not study it.  However, I sometimes hear dietitians using the terms "incomplete" and "complete" proteins.  I am curious to get some input from the professionals on this site about the concept.  What does it mean?  Is it valid?  Do you base your recommendations on it? 
Thanks.

MH

I agree that this is primarily an out-of-date concept. I DO talk about protein choices with people who are vegetarian, encouraging them to consume a variety of different protein sources throughout the day. I had a similar discussion yesterday with a woman who's daughter is following the Kind Diet, by Alicia Silverstone and Neal Barnard, MD. She's concerned that her daughter isn't getting enough total protein, yet when I explained that protein is in a variety of foods (all of whicih her daughter eats daily) she realized it's not the big issue she imagined.

However, it's not uncommon for me to talk with people who are vegetarian but eat no soy products, legumes, or dairy. These folks DO need to pay attention to their protein choices, as well as learn healthy eating habits overall.

 I do discuss the concept of complete versus incomplete proteins with my patients . The patients may know  that foods  such as meat, fish, eggs, cheese and some plant food sources such as soybeans, buckwheat, quinoa  have all the essential amino acids, but, they need help understanding the concept of protein combining in order to come up with a diabetes-friendly meal plan. For example, I  share the following practical/educational tips with my patients in order to help them with their meal/snack planning and feel that the tips help them in the long run:

 peanut butter on a slice of whole wheat bread

•  casserole with a small amount of meat
•  salad with beans and a hard cooked egg
•  yogurt with a bit of granola
•  a small bean and cheese burrito
•  macaroni and cheese
•  oatmeal with milk
•  tofu-vegetable stir-fry over rice or pasta
• rice and beans

The Vegetarian Resource Group is an excellent source of research-based information on vegetarian diets. They state upfront in their article on protein and the vegan diet that:

"It is very easy for a vegan diet to meet the recommendations for protein, as long as calorie intake is adequte. Strict protein combining is not necessary; it is more important to eat a varied diet throughout the day."  http://www.vrg.org/nutrition/protein.htm

This article goes on to explain how the myth of protein combining first got started, and why it's much simpler than we used to think to obtain a high-quality protein diet using only plant-based food sources. This article concludes with: "We recommend eating a variety of unrefined grains, legumes, seeds, nuts, and vegetables throughout the day, so that if one food is low in a particular essential amino acid, another food will make up this deficit."

Thanks for the resource.  I use the PCRM's program that got started in the last quarter for folks that are interested in taking the plung. It's a great location for them to get motivated and to learn how to prepare foods without animal protein sources.

http://support.pcrm.org/site/PageServer?pagename=21day_vegan_kickstart&JServSessionIda003=upegog3qg1.app234c