Why are not all proteins created equal?

Not all proteins are the same. Protein sources react differently in the body depending on unique absorption rates and different levels of essential and non-essential amino acids.

Why are not all proteins created equal?

Not all proteins are the same. Protein sources react differently in the body depending on unique absorption rates and different levels of essential and non-essential amino acids. The unique amino acid composition of proteins affects how the body is able to use them for growth, recovery and maintenance. Consumers are realizing the benefits that dietary proteins can provide.

However, not all proteins are produced the same way, from endurance athletes and those who work out on weekends to those who are elderly. When it comes to the composition of amino acids in proteins, some protein sources better meet human needs than others. Protein is a key part of any diet. The average person needs about 7 grams of protein per day for every 20 pounds of body weight.

Because proteins are found in a large number of foods, many people can easily achieve this goal. However, not all protein “packages” are manufactured the same way. Because foods contain much more than protein, it's important to pay attention to what they contain. Therefore, on the healthy eating plate, it is recommended to choose healthy foods with proteins.

The following table shows a comparison of the amount of broccoli, cod and “plant-based” donut to obtain 100 g of protein. According to scientists at the University of Arkansas, animal proteins have greater protein digestibility and a better profile of essential amino acids in relation to dietary needs. This won't be news to anyone. However, since the rise of plant-based diets seems unstoppable, numerous investigations have recently been devoted to evaluating how comparable plant-based protein is to its animal counterparts.

The National Academy of Medicine also establishes a wide range of acceptable protein intake, which ranges from 10% to 35% of daily calories. Whole-body protein balance increased more in the beef, pork, and egg groups than in all groups that consumed plant-based protein food sources. And most other developed countries have a deficiency, because protein-packed plant and animal foods abound. As a result, the researchers state that “the equivalents in ounces of protein foods, as expressed in DGAs, are not metabolically equivalent either in terms of anabolic response or caloric value, and this must be considered as ADGs are developed.

New research states that animal protein sources provide a greater net protein gain than plant-based ones and therefore should not be considered the same. An analysis conducted at Harvard with more than 130,000 men and women who were followed for up to 32 years found that the percentage of calories in total protein intake was not related to overall mortality or to specific causes of death. Changes from baseline after consumption of the different protein food sources were compared to that person's starting value. Proteins are made up of building blocks called amino acids, which are then linked together by peptide bonds to create larger peptide units.

A corresponding editorial by Glenda Courtney-Martin (University of Toronto) highlights the importance and timely contribution of this study, which could guide future decisions on how ADGs can better classify protein foods. A new study (funded by Beef Checkoff, National Pork Board, and the Egg Nutrition Center of the American Egg Board), recently published in The Journal of Nutrition, investigated the physiological response to several ounce equivalents of protein food sources and found that consuming ounces equivalent to ounces of animal-based protein food sources produced a greater increase in net whole-body protein balance than ounce equivalents of plant-based protein food sources. Consuming ounce equivalents of animal-based protein food sources resulted in a greater increase in whole-body net protein balance above the initial value than ounce equivalents of plant-based protein food sources.