I’ve had two people recently ask me to talk a bit about protein. I’ll admit that asking a plant based physician taking a nutrition course to talk about protein is a bit like asking a Trekkie what their favorite Star Trek episode is. So rather than diving into this topic as I am usually want to do, I thought I’d toss out a couple of snippets and see what bounces back. If you read something that interests you, let me know and I’ll make it the topic of a future post.
- How much protein is needed? The flippant answer is YMMV (your milage may vary) because the RDA (recommended dietary allowance) is based upon your body weight. Thus, everyone’s “number” is a little different. But, practically speaking, the numbers are not that different. The RDA figure is based upon the EAR (estimated average requirement), previously called the Minimum Daily Requirement. The EAR is 0.5–0.6 grams of dietary protein per kg body weight per day. In order to account for variations in diet, activity levels, etc. the RDA is constructed to encompass the EAR + 2 standard deviations. In this way, the RDA encompasses the needs to over 95% of the population and only about 2% (on the low side only) won’t have their protein needs met by following the RDA. So, what is the RDA? The RDA for dietary protein is 0.80 grams of dietary protein per kg body weight per day. So, if you’re a 150 pound person (68 kg) your RDA of dietary protein is 55 grams. Expressed as the percent of total diet calories, protein should comprise 8-10% of total dietary calories.
- It is important to note that the RDA is NOT the recommended minimum. It is the recommended TOTAL amount of protein necessary to maintain good health.
- A plant based diet naturally provides 8-10% of calories as dietary protein. While it is possible to push total protein intake to higher levels without consuming animals, it is difficult and requires the use of plant protein supplements. Given the inherent problems with high protein intake (see #8, below) there is no reason to do so.
- Is there a way to mix some meats into a plant based diet and still stay around the 10% level of calories as protein? Not really. Since a plant based diet alone provides perfectly adequate amounts of protein any additional protein as meat will push the total protein amount up into unhealthy territory.
- Do plants need to be “combined” to provide adequate and complete protein. Short answer: no. Long answer: no. 🙂 There was some concern about this many years ago, but it is widely understood that anyone eating a varied whole grain plant based diet need not concern themselves with protein combinations.
- Is animal protein needed for any reason? Again, short answer is no. The longer answer is also no, but the interested reader should have some information on why there is such a widely held misconception that animal protein is better for you than plant protein. I would argue, in fact, that exactly the opposite is true. But back in the early days of protein science, it was observed that animal proteins were used “more efficiently” than plant based proteins. That is to say, when people and animals are fed animal protein, which closely resembles their own protein in composition, the enzymes to digest the animal protein, the absorption, and subsequent utilization of the protein is all more easily done. As a result of this observation, animal based protein was labelled as “high quality” protein and plant based protein was labelled as “low quality” protein. The seemingly obvious follow up to that observation is: does it make a difference? And the answer is yes, but not how you think it does.
- Diets high in “high quality” animal protein do stimulate faster body growth rate and production of more growth factors. In a previous post I reported that American’s were not only getting fatter, but also taller. Unfortunately, weight is increasing faster than height, so body mass index (BMI) is increasing as well. But, it turns out that increased growth rate and growth factor production also means more cancer, which is just as stimulated by the protein as normal cells. It’s why we’re seeing earlier and earlier menarche (age of beginning menstrual cycles) in our girls, which increases the lifetime exposure of mammary tissues to increasing amounts of estrogen, which results in increasing breast cancer rates. It also means more growth factors, like Insulin-like growth factor 1 (IGF-1), which was implicated in increased cancer rates.
- Last for today, increased total protein intake is associated with “diseases of affluence”. This includes cancer, heart disease, diabetes, kidney disease and similar long term illnesses. Higher protein intake is independently associated with elevated cholesterol levels. Animal proteins are, by necessity, associated with animal fats (i.e. saturated fats, the ones you’re not supposed to have). Thus a diet rich in animal protein must also be rich in fat. Lastly, a diet of animal proteins and fats is associated with elevated dietary acids, that leads to leaching of calcium from the bones and osteoporosis. It’s well established that countries with the highest meat and dairy consumption have, by far, the highest rates of osteoporosis.
Hope this gives you all a bit to ponder. As I said before, let me know and I’ll be glad to expand upon any or all!
2 replies on “Let’s Start to Talk About Protein”
Shopping last night, I noticed the cereal aisle full of cereal boxes with ‘protein’ in bold letters on the box. It seems to be the buzz word with energy bars too. When did we become obsessed with protein and what is the perception it’s doing for us? Is it riding the sport drink wave or tied to the protein diet that was a fad not long ago (that I can’t remember the name of right now)?
You’ve got a protein twofer there! It seems pretty clear that the chemists and nutritionists that “discovered” and first studied protein back in the 1830’s and on through the century noted the importance of this macronutrient to growth of experimental animals. (There are 4 macronutrients in food: protein, fat, carbohydrate, and water) Protein is pretty much the only way to get nitrogen into the system, so it is important not only for basic health, but also for growth, which relies on an adequate supply of “building blocks” and enzymes to facilitate growth. Also, there was (and still is, I would argue) a fundamental gestalt that being able to afford to eat animal flesh was a sign of success and prosperity. And animal products, whether flesh, milk or eggs, contain no carbohydrate at all. So protein was: 1) essential for health, 2) a proven facilitator for growth and 3) a status symbol. In one of those funny little twists that occur throughout science, Carl Voit, the “Father of Nutrition” experimentally showed that an adult male human requires about 52 grams of protein a day for health ( a number that fits very closely to current RDA), but when he published his first dietary recommendations, he arbitrarily increased that to 120 grams with a “more is better” mentality.
The second part is food companies capitalizing on the belief that non-animal sources of food need to be protein “fortified” to be healthy. It’s a continuation of the strong misconception that plant based protein is somehow insufficient because it is “low quality”. And it is true that our bodies do not handle plant based protein quite as efficiently as they do animal based proteins, but that does not, in any way, mean that plant based protein is insufficient. When you are starting your bonfire, paper is a much less efficient accelerant than gasoline, but much safer.
Finally, I think you’re thinking of the Atkin’s Diet. The Atkin’s diet prohibits all carbohydrate and allows only protein and fats. Since the brain and many of the body systems require carbohydrate to function, the body is switched into a metabolic mode called ketosis in order to make sugar from protein and fat. This is a very inefficient and dangerous process. This is also exactly what happens to insulin dependent diabetics that don’t take their insulin. The ketosis house of cards falls apart the very moment any carbohydrate passes your lips, though, which is why this “diet” has a zero long term success rate and should not be condoned by any responsible physician or nutritionist.