It seems like every other food on the supermarket shelves is touting how much protein it contains, leading you to believe that we are all protein deficient. Nothing could be further from the truth. Most Americans get 16% of their total calories from protein which equals 1.2 to 1.5 grams per kilogram daily. The recommended dietary allowance (RDA) for protein is set at 0.8 grams per kilogram.
Our protein needs in both quantity and quality is complicated. Protein comes from both animal and vegetable foods. The type or quality of protein is defined by the amino acid building blocks the protein contains. Food protein is broken down into amino acid fragments during digestion. These individual amino acids are used by the body for growth, to transport and store nutrients, to repair tissues, and to remove wastes. Amino acids can even provide energy for the body, but only when other sources like carbohydrates or fat are not available.
How effectively our bodies use the protein we get from food depends on a number of factors. In the US we tend to skew our protein intake for the day toward dinner with less protein eaten at breakfast and lunch. This may not be the best pattern for optimum protein utilization. Research has suggested that spreading our protein intake throughout the day with each meal containing 25 to 30 grams of protein is the best way to utilize protein efficiently, build and repair muscles, and cut down on hunger.
Protein quality is also important. Amino acids are classified as essential and nonessential. The nonessential ones can be made in the body. Essential amino acids cannot and must be supplied by the protein foods you eat. Animal-based proteins – meat, fish, poultry, eggs, dairy – contain all 9 of the essential amino acids in optimal amounts to be used efficiently. Plant proteins may lack one or more of the essential amino acids or may provide a very limited amount. Beans are low in methionine.
To offset the limiting amino acids in plant-based proteins, in the past people were advised to eat plant proteins that complimented each other to make the total amino acid picture more like one found in animal-based protein foods. Food pairs that do this include – a peanut butter sandwich on whole wheat bread, tofu and brown rice, beans and nuts on a salad, soy milk and cereal. Though these pairings are still excellent to boost protein quality, we now know that the complimentary plant proteins do not have to be eaten at the same meal. As long as various plant-based proteins are eaten throughout the day the body can make use of their amino acids to build and support the body’s needs.
To learn more about protein take a look at our book Protein Counter available as a ebook.
