All About Protein
If you've followed any of my Facebook posts, you would know that I speak a lot about macronutrients, or macros for short. When looking at the diet as a whole, macronutrients are basically nutrients of larger particle size that make up the bulk of any existing diet and are required to produce sufficient energy for daily activities.
To support training and competition, athletes and active individuals should consume a balanced diet that provides all the essential nutrients: carbohydrates, protein, fat, water, vitamins, and minerals [3]. Let's take a look at dietary protein in depth while also addressing common points of confusion such as:
• What is protein?
• What are great sources of protein?
• How much protein do I need?
• Is a high-protein diet safe?
Hopefully you're not following the average American diet which tends to consist of a majority of daily calories coming from fats and carbs (often times in overconsumption) with little regard for protein intake. Individuals with these dietary habits seem to directly correlate with those that likely have unfavorable body composition coupled with potential health complications such as high blood pressure, high cholesterol, cardiovascular disease, and various forms of metabolic syndromes. Long-story short, you NEED protein and should pay attention to your daily protein consumption particularly if your goal is to improve body composition and long-term health.
What is Protein and where do I get it?
Not peanut butter. Don't you dare say peanut butter! Likely due to marketing, people tend to think peanut butter is a significant source of protein. At a whopping 8 grams of incomplete proteins per serving and roughly ~16g fat, any nut butter would not fit into the protein category and would be a significant source of fat.
Just likes carbs and fats, protein is composed of carbon, hydrogen, and oxygen atoms. The only difference between protein and the other two macros is that proteins also contain nitrogen. Protein consists of amino acids; "amino" means "nitrogen-containing."
Without going into too much science just know that there are high quality proteins and proteins that are lower in quality but still very useful; complete and incomplete proteins. High quality proteins are those with a high biological value or a complete protein in most cases.
This just means high quality protein sources are those that contain all of the amino acids the body needs such as those from animal origin (eggs, meat, fish, poultry, and dairy products) [3].
Lower quality proteins, or incomplete proteins, are those that are deficient in one or more of the essential amino acids (grains, nuts, beans, vegetables, and gelatin). Soy protein is the highest in quality in contrast to other lower quality sources.
More often than not, those that follow a vegan diet are typically very educated when it comes to the topic of discussing protein needs since they choose to only consume plant protein sources. Variety with a vegan diet is very important in order to provide a plethora of amino acids from different sources by consuming complementary proteins.
Although complementary protein sources do not have to be consumed in the same meal sitting, common combinations include beans and rice, corn and beans, hummus and pita chips, and peanut butter on bread. These are all great ways to provide the body with the appropriate amount of essential amino acids.
On a side note, if you are consuming more than the RDA for protein requirements (you should be), you likely won't need to worry about complete or incomplete proteins.
How much protein do I need?
Ah, the million dollar question...unlike carbs and fat, little of the protein you eat is used for energy (unless in caloric restriction). This means "extra protein" does NOT turn into body fat.
Protein's role in the body is to serve as building blocks for new tissue, repair tissue, and replace protein in your existing cells. Exercise and and strenuous physical activity increase cell turnover, which is the constant breakdown and regeneration of cells. This is one of the major reasons why athletes and fitness enthusiasts need to put priority on protein intake if your goal is to increase or maintain muscle size, strength, and optimize recovery [1].
How much protein an individual needs is largely variant on factors such as caloric intake, biological value of the protein consumed, body composition, and types of exercise you engage in along with the duration and intensity of that exercise [1]. If you are sedentary then your protein requirements are much lower than those of someone that performs resistance training on a regular basis. If you are in a chronic net caloric deficit (fewer calories consumed than expended) with the purpose of trying to reduce weight/body fat then protein requirements become higher as protein can be metabolized as a source of energy.
At a minimum, typically for inactive folks, the Recommended Daily Allowance (RDA) for protein intake is 0.8g/kg of bodyweight per day (0.36g/pound). That's not much protein at all but it's enough to maintain general health.
For individuals that participate in regular aerobic endurance training, the demands of the training increase the needs for protein within the range of 1.0-1.6g/kg (0.45-0.73g/lb) of bodyweight; more towards the upper ranges for longer durations or higher intensity. Endurance athletes need more protein in comparison to sedentary folks for the purpose of tissue repair as well as the increased breakdown of branched chain amino acids used as a fuel source during exercise.
Athletes participating in heavy resistance training have even higher protein needs within the range of 1.6-3.0+g/kg/day (0.73-1.36g/lb/day of lean body weight).
To make it less confusing, if you are an endurance athlete or strength/power athlete, consume protein somewhere within the range of 1.4g/kg-3.0+g/kg to cover all your bases. This is of course assuming you are consuming adequate calories and not in a caloric deficit as this would increase your protein needs to around 2.0g/kg or greater [1,2].
The one caveat to these recommendations is if you are obese in which case you would consume enough protein to support your TARGET body weight. To make things easier without multiplying decimals, aim for around a gram of protein per pound of bodyweight provided that you do not have a significant amount of body fat to lose.
How safe is it consuming a high-protein diet?
If you go over these amounts, then it's no big deal. There is no evidence in healthy individuals without renal complications to suggest that a high-protein diet is dangerous or detrimental to health. As a matter of fact, in a 2000 study published in the International Journal of Sport Nutrition and Exercise Metabolism, researchers concluded that "protein intake under 1.27g/lb of bodyweight per day does not impair renal function in well-trained athletes, as indicated by the measures of renal function used in this study." Protein restriction may be valid in those with existing kidney disease but there is no significant evidence to support the idea that a high-protein diet has detrimental effects on kidney function in healthy individuals [4,5].
You may have also heard a myth circulating on the internetz and media outlets that a high-protein diet can be harmful to your bones. This is completely contradictory to human physiology and I'm not sure how people come to these conclusions!
Not having enough protein in your diet leaves you at a much higher risk for lower bone mineral density and bone loss [6,7]. I'm sure you've heard of an elderly individual or possibly a family member, falling and breaking their hip or surrounding structure. These bone fractures could have likely been prevented during a fall if their dietary protein intake was adequate (along with creatine supplementation to maintain lean tissue and strength). Research from 1998 found that protein supplements provided to elderly subjects helped them to heal faster from bone-related injuries, specifically femoral fractures (the hardest bone in the human body). Supplementing with 20 grams of protein a day not only reduced bone loss but also allowed them to return home sooner from rehab [8].
By now I'm likely losing your attention with all of this science. The general consensus of the scientific literature concludes that protein intakes for athletic or physically active individuals is between 1.2g-3.0+g/kg of bodyweight. Again, this may need to be higher if you're in a caloric deficit with the purpose of shedding body fat.
From practical experience over the past decade, I've seen clients make impressive results consuming around one gram per pound of body weight for leaner individuals and similar results for clients that had more body fat to lose using target body weight.
In part 2 of this article series on protein, I'll discuss how a higher protein intake will help you to lose weight. Being more specific - increasing your protein intake aids in losing body fat and building or maintaining muscle. Also, I will discuss what kinds of protein are optimal along with the best time to consume it.
References:
• Campbell Bill, Richard Kreider, Tim Ziegenfuss, Paul La Bounty, Mike Roberts, Darren Burke, Jamie Landis, Jose Antonio, and Hector Lopez. "International Society of Sports Nutrition Position Stand: Protein and Exercise." Journal of the International Society of Sports Nutrition. JISSN, 26 Sept. 2007. Web. 23 Sept. 2013. <http://www.jissn.com/content/4/1/8>.
• Lemon, P.W.R. Effects of exercise on dietary protein requirements. Int J Sports Nutr. 8:426-447.1998
• Reimers, Kristin. "Chapter 10: Nutritional Factors in Health and Performance."Essentials of Strength Training and Conditioning. 3rd ed. Champaign, IL: Human Kinetics, 2000. 206-08. Print.
• Poortmans JR and Dellalieux O. Do regular high-protein diets have potential health risks on kidney function in athletes? Int J Sport Nutr Exerc Metab. 2000; 10 (1):28-38.
• Martin WF, et al. Dietary protein intake and renal function. Nutr Metab. 2005; 2:25.
• Heaney RP. Effects of caffeine on bone and the calcium economy. Food Chem Toxicol. 2002; 40 (9): 1263-70.
• Kerstetter JE, et al. Low protein intake: the impact on calcium and bone homeostasis in humans. J Nutr. 2003; 133 (3): 855S-861S.
• Porter KH and Johnson MA. Dietary protein supplementation and recovery from femoral fracture. Nutr Rev. 1998 Nov; 56 (11): 337-40.