Protein combining

Protein combining (also protein complementing) is a controversial theory that vegetarians, particlarly vegans, must eat certain complementary foods like beans and rice together in the same meal. The purpose of protein combining is to ensure that plant foods with incomplete essential amino acid content combine to form a complete protein, meeting all amino acid requirements for human growth and maintenance.

Many health organizations now consider protein combining within the same meal to be unnecessary.cite web
title = Vegetarian Diets
url = http://www.mypyramid.gov/tips_resources/vegetarian_diets.html
publisher = United States Department of Agriculture
accessdate = 2008-06-18
quote = Combining different protein sources in the same meal is not necessary.] cite web
title = Position of the American Dietitians Association and Dietitians of Canada: Vegetarian Diets
url = http://www.dietitians.ca/news/downloads/vegetarian_position_paper_2003.pdf
publisher = Dietitians of Canada
year = 2003
accessdate = 2008-06-18
quote = Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults; thus complementary proteins do not need to be consumed at the same meal.] Instead they recommend that vegans consume a variety of plant foods to ensure that all protein requirements are met.

ource of the theory

The protein combining theory was based on interpretation of studies performed in the early 1900s on the growth of rats. The theory entered popular consciousness with the publication of Frances Moore Lappé's 1971 bestseller "Diet for a Small Planet". In later editions of "Diet for a Small Planet", beginning in 1981, Lappé changed her position on protein combining. In this later edition, Lappé wrote:

:"In 1971 I stressed protein complementarity because I assumed that the only way to get enough protein ... was to create a protein as usable by the body as animal protein. In combating the myth that meat is the only way to get high-quality protein, I reinforced another myth. I gave the impression that in order to get enough protein without meat, considerable care was needed in choosing foods. Actually, it is much easier than I thought.

:"With three important exceptions, there is little danger of protein deficiency in a plant food diet. The exceptions are diets very heavily dependent on [1] fruit or on [2] some tubers, such as sweet potatoes or cassava, or on [3] junk food (refined flours, sugars, and fat). Fortunately, relatively few people in the world try to survive on diets in which these foods are virtually the sole source of calories. In all other diets, if people are getting enough calories, they are virtually certain of getting enough protein." [Diet for a Small Planet (ISBN 0-345-32120-0), 1981, p. 162; emphasis in original]

Current status

Some nutritionists and health institutions continue to present protein combining as a recommendation for vegetarians and vegans. However, this recommendation has been challenged as unnecessary and misleading by vegetarian and vegan associationscite web
title = Protein in the Vegan Diet
url = http://www.vrg.org/nutrition/protein.htm
publisher = Vegetarian Resource Group
accessdate = 2008-06-18] cite web
title = Protein
url = http://www.vegansociety.com/food/nutrition/protein.php
publisher = Vegan Society
accessdate = 2008-06-18] and some nutritionists. [ [http://www.nealhendrickson.com/mcdougall/021100puletter.htm McDougall vs. the American Heart Association] ]

References