About a year ago, I wrote an article titled “How much protein do I need?“. This article is a follow-up based on the best research that I’ve read since then. If you want the basics on why protein is so important, please refer to the above article; and perhaps this one on collagen.
This (i.e.: “How much protein per day do I need?”) is a question that I do NOT get asked often enough from patients. Of course everyone’s needs are different, so there is no magic number for everybody. When it comes to protein (and other nutrients), it depends on weight, along with stress and activity levels. In wanting to stay up to date on the best information, I recently came across a spectacular article that talks all about protein requirements.
Before I summarize the article, I thought it would be interesting to point out the etymology of “protein”. The English word “protein” is derived from the Greek word “proteios”, meaning “chief rank”, “first place”, or “primary” depending on where you look. I feel that alone is enough to express the importance of getting ample amounts of protein everyday. That said, let’s now see why.
The author, Donald K. Layman makes four basic points about the importance of protein.
The key concepts are as follows:
1) “Protein is a critical part of the adult diet”
2) “Protein needs are proportional to body weight; NOT energy intake”
3) “Adult protein utilization is a function of intake at individual meals”
4) “Most adults benefit from protein intakes above the minimum RDA”
Let’s look at these points in more detail.
Number 1 – Well, this is generally obvious so I won’t expand on this point. You can read my other articles linked above if you’re not sure why it’s “critical”.
Number 2 – When a person asks me (or I determine) how much protein they need; I base it on body weight and physical activity as mentioned above. Layman says specifically, “protein needs are proportional to body weight; NOT energy intake”. This means that you and I need to consume a certain number of grams of protein per day based on how much we weigh and NOT simply on a percentage of total caloric intake per day. So it wouldn’t be wise to say, “I eat a 2,000 calorie per day diet, follow a strict 40-30-30 diet (carbs, protein, fat respectively) and therefore I’ll eat “x” number of grams of protein per day”. Depending on how much you weigh, you could be shorting yourself with a formula like this. Since protein requirements are based on body weight, you’d actually need to increase the percentage of protein in your diet if you restricted your total caloric intake (as one might if attempting to lose weight).
What’s the magic number you ask? Well, the minimum RDA (recommended daily allowance) is 0.8 g/kg of body weight. The minimum number of grams per day can therefore be determined by dividing your weight in pounds by 2.2 and then multiplying that number by 0.8. So a 150lb. person would need a minimum of about 55 grams per day (150/2.2 = 68 x 0.8 = 54.4). Remember now, this is the minimum! RDA is intended to be “the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (approximately 98 percent) healthy individuals”. I’ll get to more specific numbers soon, let me move on to point number 3.
Number 3 – Again, the third point reads: “Adult protein utilization is a function of intake at individual meals”. Note the term “protein utilization”. This is certainly worth looking into because after all, what good is protein intake if it’s not being utilized. Layman goes on to say that current guidelines focused on the RDA minimize the importance of having protein at every meal. When it comes to children and young adults, this point isn’t as critical; because “uneven meal distribution of protein appears not to adversely affect growth” in that age group. However, in adults (because of changes in metabolism) this is a very critical point. Layman’s research says: “Adults require a minimum of 15 grams of essential amino acids or at least 30 grams of total protein to fully stimulate skeletal muscle protein synthesis”. [italics and underlining added by me] In adults, diets that contain adequate protein at only one meal produce this beneficial effect only after that meal. So getting most of your days intake by eating say a steak or other significant source of protein at dinner alone will not cut it. Also, he cites two studies after saying “most adults consume less than 10 grams of protein at breakfast”.
Number 4 – This reads: “Most adults benefit from protein intakes above the minimum RDA”.
Bear in mind this last critical point because protein is not only beneficial for muscle and tissue growth. To quote Layman again, he says: “During the last decade a growing body of research reveals that dietary protein intakes above the RDA are beneficial in maintaining muscle function and mobility and in the treatment of diseases including obesity, osteoporosis, type 2 diabetes, Metabolic Syndrome, heart disease, and sarcopenia”. Even further health benefits include satiety (essentially feeling full and not wanting to eat more), thermogenesis (basically increasing the rate that the body burns stored fat allowing for the release of energy), and my personal favorite glycemic (or blood sugar) control.
I can’t think of a single patient who is ever fat- or carbohydrate-deficient, but protein-deficient, absolutely!
Last and not at all least, the utilization of your protein intake won’t occur very well if you’re not digesting it; and one of the most important reasons people don’t digest protein well is because of a lack of hydrochloric (stomach) acid.
Hope this helps!
Sources:
http://www.nutritionandmetabolism.com/content/6/1/12
http://www.dietandfitnesstoday.com/rda.php
Dr. Robert D’Aquila – NYC Chiropractor – Applied Kinesiology