Not All Protein is Created Equally

America's focus on nutritious eating began to receive national attention in the 1940s when President Roosevelt introduced the RDA, or Recommended Daily Allowance (RDA) model. This model, which took on the shape of a pyramid in the 1980s (and hence now goes by the term "food pyramid"), has gone through a number of iterations since its inception more than 60 years ago[i].
This change and evolution of the RDA model is, in many respects, a positive step. It demonstrates that, just as America's information on diet and nutrition is advancing, so too are the models that guide its eating habits. In fact, the USDA itself has decided to update the term and now refers to "RDI's" ("Reference Daily Intake") instead of RDA's.
However, undermining some of this positive change is the fact that many Americans are increasingly confused over what, how, and when to eat. A survey conducted by the USDA in 1996 verified this fact when 40% of respondents agreed strongly with the statement that "there are so many recommendations about healthy ways to eat, it's hard to know what to believe"[ii].
One of the most serious expressions of this growing dietary confusion has to do with a concept called the Daily Value, or "DV". Introduced by the USDA in the 1990s, the DV is a dietary numerical reference that is supposed to allow people to make healthy eating choices[iii].
The philosophical idea behind the DV, which is expressed as a percentage, is that it provides a very important piece of information. The DV informs consumers how much of a nutrient they are getting from a particular food item. For example, if the DV label on a can of beans declares that it represents "10% of the DV for fat", then consumers can keep track of that number to know if, throughout the day, how much fat they are eating[1].
However, one does not have to be a mathematician or a dietician to see that the above idea begs a significant question: is this10% of the DV for fat "good" or is it "bad"? In other words, should a consumer choose this source of fat because it represents a good source of fat, or avoid it for the opposite reason?
It is this question that has caused so much confusion among health-conscious consumers. It has caused particular anxiety among those who are wisely ensuring that they eat the recommended daily allowance for protein.
The importance of protein in diet cannot be understated. It is not simply an essential macronutrient for athletes, such as bodybuilders and runners. Protein is critical for life itself, regardless of mobility or athleticism. Among other essential functions, protein maintains and repairs muscle tissue, aids digestion, regulates chemicals, manages hormones, and produces enzymes[iv]. In extreme cases, a dangerous lack of protein actually leads to a condition called Kwashiorkor, where the body cannibalizes itself[2].
Trying to determine the right amount of protein – as expressed in terms of DV% -- has been a difficult challenge for most eaters. Unfortunately, as a result of this confusion, some consumers have not been eating high quality protein. This is because the DV number is simply not enough information upon which they can make healthy protein eating decisions.
The missing number in the DV equation is the Reference Daily Intake (RDI) level. The RDI for protein is, generally, 50 grams per day. Consumers can take the number of total grams of protein in a product, and divide it by this RDI for protein to determine what the "optimum" DV number should be.
For example, if a product offers 25 grams of protein, and the RDI is 50 grams per day, then the product's "optimum" DV will be 50%. Therefore, the figure "50%" should appear on the product's labeling. If the number is lower than 50%, the consumers instantly know that it is not an optimum source of protein.
Finding high quality sources for essential micronutrients like protein (among others) is a challenge that should not be difficult, but it is, because some food makers do not want to educate consumers on how to detect high quality from low quality. This is particularly unfortunate in the health and nutrition food industry, where one would expect manufacturers strive for high quality nutrition. Regrettably, this is not always the case.
However, that is not reason to despair. Rather, it just as much reason to support companies that are making the effort to ensure that their products reflect only high quality DV levels, and a concurrent effort to educate the public on how to determine optimum DV.
[1] The FDA is clear that the DV concept is not intended to direct people on how much they should eat. In this example, the eater should not conclude that eating 10 cans of beans will achieve "100% of the recommended fat intake per day". The DV is intended as a reference number only and not as a recommendation. The intake per day is suggested by the RDA/RDI, which will be discussed further in this article.
[2] Kwashiorkor is more prevalent in some parts of the developing world, but incidences have been reported in the US.
References
[i] Source: "Food Pyramid History".
http://iml.jou.ufl.edu/projects/Fall02/Greene/history.htm
[ii] Source: America's Eating Habits: Changes and Consequences. USDA.
http://www.ers.usda.gov/publications/aib750/
[iii] Source "Daily Values Encourage Healthy Eating". FDA.
http://www.fda.gov/fdac/special/foodlabel/dvs.html
[iv] Source: "The Importance of Protein". OhioHealth.