Now that we know about you, let's figure out how much protein in diet you need. Click the button below to make the final calculations. The end goal is to give you the ability to make better choices and provide a rough guideline for protein's role in your healthy diet plan.
Protein in diet has significant importance to our health and there are a few considerations to make from the wide variety of food sources rich in this macronutrient. We should focus on first seeking high-quality for your healthy diet plan.
There are two characteristics that define high-quality protein. Complete proteins contain all the essential amino acids needed from diet to act as building blocks for a wide array of proteins.
The second principle of high-quality protein is for it to be easily digested and absorbed into our system. Among the worst offenders are refined grains as breakfast cereals and dried beans, especially of the black, kidney and pinto varieties.
However, one of the most heavily cited scholarly articles on the subject suggests that protein digestibility is of greater concern in the diets of developing, and often impoverished, countries. Diversity in protein sources is the driving factor behind this conclusion. Including strict vegetarians, the digestibility of protein in diet is estimated to be between 88% and 94% in North America.
Over the years, several rating systems have been created to determine and rank the highest-quality protein sources. The most prominent and acknowledged system today takes into account both characteristics, completeness and digestibility.
The Protein Digestibility Corrected Amino Acid Score (PDCAAS) rates food sources on a 0.00 - 1.00 scale, where any food with a score of 1.00 is considered essentially a perfect protein. There are only two whole foods that get top marks for protein in diet: cows milk and eggs.
The World Health Organization has very recently published a review of the PDCAAS exposing its shortcomings and plan to implement a more accurate system in the near future. We should treat the PDCAAS as a tool to help educate ourselves, not as mantra. As we will see, obtaining high-quality protein from single food sources isn't the only option for your healthy diet plan.
Our bodies use amino acids in specific proportions to one another and can only function as well as their weakest link. When one or more of the nine essential amino acids is lacking in the diet, all proteins which need the limiting amino acid as part of their blueprint cannot be made.
This potential deficiency essentially limits the usefulness of all the other amino acids. As a result, eating only complete proteins has been touted as the only guaranteed way to avoid this issue. More importantly, a bad reputation has been given to protein sources that have a limited amino acid profile called "incomplete proteins." Let's address this issue.
No protein source is truly incomplete. All proteins sources have some amount of each of the nine essential amino acids, but many foods have less than ideal proportions of these amino acids.
In the early 1970's, a now infamous book was published proposing a solution to global hunger, but in the process introduced a theory to alleviate essential amino acid imbalance. Francis Moore Lappe's "Diet for a Small Planet" advocated protein combining, which suggested that eating certain foods together would compensate for the other's limiting amino acid(s) would effectively create a complete protein.
Let's use a popular cultural meal combination to serve as a concrete example. Rice and beans taste delicious together, but also compliment each as proteins. Rice has a strong amino acid profile but is lacking in lysine. On the other hand, most varieties of beans are rich sources of lysine but are limited in methionine. Together, they create a well-proportioned profile of essential amino acids comparable to any single, complete protein source.
It has been argued in the Journal of the American Heart Association that mixing foods to create complementary proteins is superfluous. The medical doctor authoring the review went as far to state that even "a vegetarian diet based on any single or combination of unprocessed starches, with the addition of fruits and vegetables, supplies all the protein [and] amino acids... necessary for excellent health."
Nutritionists, dietitians, and, even Lappe now wholeheartedly agree that the theory of protein combining is unnecessary. Why?
Free amino acids circulating throughout our bloodstream form a "pool" which represents the primary source to build proteins. While this pool is fluid, it is estimated to be 100 grams of well-proportioned essential and non-essential amino acids. As proteins are broken down reusable amino acids enter the pool, while those in excess are converted to energy or excreted as waste. Our bodies are very sophisticated!
Basically, our amino acid pool acts as a reserve. As long as we continue to replenish it with a variety of food sources our amino acid pool will continue to thrive, and our bodies will function at full capacity.
Selecting a diverse source of animal and plant-based proteins according to the guidelines in the Daily Food Guide will provide high-quality proteins in your healthy diet plan that will always be complete!
On the outside, making protein an increasing part of our diet seems like a win-win proposition. After all, our bodies choose to use its glycogen (reserves of carbohydrates) and burn excess fat before converting protein to energy.
One of the current nutrition trends in the modern diet is to include more protein. Its ability to give a feeling of fullness, known as satiety, is a key reason for the push to do so. There is merit in this view, it is only half of the story. Most nutritionists would agree that being deficient in protein is a condition limited to the developing world.
Nutrition guidelines set forth by global health agencies and federal governments believe that we need approximately 5% of our calories from protein to survive.
The generally accepted range is between 10% - 35% of calories from protein. As you can see, this is a large range and part of creating your healthy diet plan is to determine the amount of protein - along with other nutrients - needed specifically for your body. We will be getting to that very shortly.
A common theme underlying Healthy Diet Mentor is balance.
As stated previously, the balance of nitrogen in the body is the primary way to test if we are getting enough, or too much protein in diet. Under normal circumstances, in healthy adults maintaining lean body mass and weight, the amount of nitrogen leaving our bodies should equal the amount of nitrogen coming into our bodies. This is nitrogen equilibrium.
Listed below in the table are situations where positive and negative nitrogen balances can occur. In either case, the intake of protein should be increased to accommodate the body before returning to nitrogen equilibrium.
Positive Nitrogen Balance
Negative Nitrogen Balance
Individual intakes of protein do not need to be monitored to the exact gram in your healthy diet plan, but despite common belief, taking in too much protein in diet can have significant risks just as not taking in enough. It has been estimated in the American Journal of Clinical Nutrition that the average adult protein intake is as high as 113 grams/day.
Compare that number to your recommendation. In many instances, this average intake calculated by the AJCN is too high. However, a valid question to raise is how Healthy Diet Mentor creates its recommendations.
In a well-controlled and frequently cited study that evaluates protein requirements for individuals, the authors compared strength athletes to people with who have sedentary lifestyles. They found that nitrogen equilibrium in strength athletes was reached at a level double the amount of protein in diet as that of the less-active individuals. This may seem intuitive but it brings home an important point.
The study concluded that a protein intake of .89 grams/kilogram for sedentary people and 1.76 grams/kilogram for strength athletes was recommended, which is aligned with the nitrogen balance data. Any intake amount higher for the respective lifestyles showed no signs of increased protein synthesis and increased leucine oxidation, an indicator of protein overload.
Let's consider an example make light of these studies. Using the estimate of 113 grams/day consumed in the modern diet and the recommendations in Tarnopolsky's study of protein requirements, we have two different scenarios below. The results are shocking.
This amount of daily protein in diet would be sufficient for an athlete weighing about...
64 kg or 141 lbs
This amount of daily protein in diet would be sufficient for a sedentary person weighing about...
127 kg or 279 lbs
While government and health agency nutrition guidelines for protein are based solely on an individuals body weight, lifestyle is a major component that must be accounted for in determining protein in diet for your healthy diet plan.
**As always, feel free to use the navigation below to backtrack and get an overview of Healthy Diet Mentor and our plan to get you on your way to a lifelong healthy diet.
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