Three of the four macronutrients play critical roles in the healthy and proper functioning of the human body. Their roles in a keto lifestyle remain very important, however, the consumption amounts of each differ from standardized recommendations from the government and general consensus found currently in most health and nutritional documentation. Understanding the importance and role of each macronutrient provides insight into a responsible integration and adaptation to meet the goals and principles of leto or low carb living. In this article I will provide a detailed look into the macronutrient of Protein. This is Part 4 of a 5 part series on Understanding Macronutrients. Check out the rest of the series for a complete understanding of all the macros.
THE IMPORTANCE OF PROTEIN
Protein is the most important macronutrient and is required for tissue maintenance, replacement, function and growth. It is used to produce enzymes, hormones, neurotransmitters and various molecules that serve vital functions. It is essential for healthy nails, hair, cartilage, skin and is critical to building muscles and maintaining a healthy lean muscle mass. Protein is not a preferred or always used energy source, and is not stored, but if the body is not getting calories from other macronutrients it can be used for energy.
BREAKING DOWN PROTEIN
Dietary proteins are broken down into peptides and amino acids. Amino acids are the building blocks of protein and are used by the body to create new proteins needed for muscle growth, antibody production, formulation of blood cells and hormone synthesis. There are 20 amino acids used by the body and 9 of these are considered essential. These essential amino acids (EAAs) can only be obtained through dietary intake and are required for your body to properly function.
There is often debate and questions surrounding the appropriate amount of protein an individual should consume. Recommended protein intake is typically determined by a certain amount per pound of body weight. Protein intake typically correlates with growth rate which decreases from infancy until adulthood although older adults have increased needs. The 2015-2020 U.S. Dietary Guidelines recommend that 10-35% of caloric intake comes from dietary protein for adult men and women. The Recommended Dietary Reference Intakes (DRI) for both men and women is .8 grams of good quality protein per kilogram of body weight. This equals only .36 grams per pound which amounts to 56 grams per day for the average sedentary man and 46 grams for the average sedentary woman. Recent research and numerous case studies suggest that while these amounts are enough to prevent deficiency they are far from sufficient to ensure optimal health and body composition. (1,2,3)
Similar to the other macronutrients, the ideal amount of protein varies by individual and factors such as activity levels, age, muscle mass, physique goals and current state of health make a difference. A more common and mainstream recommendation for protein consumption is .6 – .8 grams per pound of body weight or 1.3 – 1.8 grams per kilogram of body weight.
PROTEIN AND WEIGHT LOSS
Protein is very important for weight loss and maintenance since it is considered to be more satiating than carbohydrates and fats. Protein at around 25-30% of total daily caloric intake has shown to increase metabolism and significantly reduce appetite. Additionally, studies have suggested that higher amounts of protein are important for those that want to maintain lean muscle mass while losing weight. A high protein intake can help prevent the muscle loss that usually occurs when dieting. Diet-induced thermogenesis is also an interesting metabolic concept that proposes increased protein intake could further facilitate weight loss. Thermogenesis is a concept that certain macros, specifically protein, cause an increase in internal energy expenditure above the basal metabolic rate. This essentially causes the body to burn more calories naturally just by eating more protein. (4,5,6,7)
RISK OF TOO MUCH PROTEIN
High protein intake has often been blamed for several health problems to include causing kidney damage and osteoporosis. The American Heart Association (AHA) warns that “Individuals who follow these [high protein] diets are at risk for…potential cardiac, renal, bone, and liver abnormalities overall.” However, recent science and research have debunked many of these claims. Although protein restriction is helpful for people with pre-existing kidney problems, protein has never been shown to cause kidney damage in healthy people. Additionally, several epidemiological studies have shown a positive association between protein intake and bone density. (8)
“We recommend protein between 1.5 and 2.0 grams per kilogram reference body weight (0.7 to 0.9 grams per pound reference weight). This translates to between 90 and 150 grams per day for a range of adults, which is about what the average adult in the U.S. is already eating. This level is well tolerated and is not associated with adverse effects on bone, kidney or other health indicators.
Volek, PhD, RD; Phinney, MD, PhD (9)
PROTEIN AND EXERCISE
Numerous studies have attempted to better define the appropriate amount of protein intake for maintenance and even more so for those exercising and trying to gain lean muscle mass. It is generally agreed upon in the fitness and nutritional world that individuals attempting to gain lean muscle mass require additional dietary protein. Studies also suggest that endurance athletes require increased protein amounts. Case studies have strongly shown that higher protein diets have consistently been shown to result in greater weight loss, greater fat loss, and preservation of lean mass as compared to lower protein diets. A common recommendation for those trying to gain muscle mass is to consume 1 gram of protein per pound of body weight. There are numerous studies that support this recommendation, some support even higher amounts, while others suggest that anything over .8 grams per pound of body weight is unnecessary. Amongst all articles, research, and studies that I have read .7 to 1 gram of protein per pound of body weight tends to be generally agreed upon with athletes and resistance trainers falling on the higher end of that range. There isn’t much research or proof of any benefit associated with eating more than 1.2 grams of protein per pound of body weight. (5,10,11,12)
PROTEIN WHILE ON KETO
As referenced above, .6 to 1 gram of protein per pound of body weight is an agreed upon range of consumption amongst recent research, science and case studies with athletes, trainers, nutritionists and doctors all in general agreement. There is generally no need to alter this amount during keto because this macronutrient remains just as, if not more, vital to your health and bodily functions. For those that are sedentary, the lower end (.6 grams) can be ideal but for those that are moderately or more active .8 grams is generally optimal. And remember, it is more satiating than fat so it is a powerful facilitation of weight loss if that is your goal. A common concern from those in the keto community is that too much protein can produce unfavorable glucose levels through the process of gluconeogenesis (GNG) and kick you out of ketosis. GNG is the process by which glucose is made out of protein (using glucogenic amino acids) in the liver and kidneys. However, this concern is largely unfounded as recent research suggests that the rate of GNG remains fairly stable in widely varying metabolic conditions. In some experiments, ingesting 50 grams of protein resulted in the same amount of glucose production through GNG as drinking water. Studies have also suggested that epilepsy patients on a modified Atkins diet consisting of 64 percent fat and 31 percent protein was optimal at reducing the risk of seizures. The digestive system is quite complex and studying diabetes has proven to be very helpful in better understanding the metabolic effects of different macronutrients and foods. Although the concern over GNG may be overstated, there is some evidence that protein may slightly increase insulin levels, however, the rise in glucagon that comes at the same time mitigates the fat-forming effects of insulin. One potential concern with any rise in insulin is the negative impacts on ketone production. People often claim that their ketone levels are reduced and witnessed through testing (blood or breath tests) after eating large amounts of protein. However, this is only temporary and likely is only a potential issue for those that are in the very early stages of the keto-adaptation phase. More science needs to be done to better understand the impacts of protein intake on ketosis, however, a potentially smart approach may be to spread out the consumption of .6 to 1 grams of protein per body weight throughout your day. Another may be to reduce your protein consumption to the lower end of this range when just starting keto and throughout the few weeks of adaptation especially if you are sedentary and not exercising often. This means that you are at least consuming .6 grams of dietary protein per pound of lean muscle mass. If you are extremely obese, a recommended practice to figure out your recommended protein amount is to determine .6 – 1 gram of protein per pound of your lean muscle mass or desired goal weight – not your actual body weight. It is mostly your lean muscle mass that determines the amount of protein that you need. (13,14,15)
RIP’D RANGER INSIGHT
I average 130-150 grams of protein daily which is approximately 25 % of my total caloric intake. This also equals approximately .83 grams of protein per pound of body weight. I work out almost daily and consume a large portion of my protein before and after my morning workouts. At about .8 grams of protein consumption per pound of my body weight I have been able to maintain and at times slightly gain lean muscle mass over the past year depending on my workout and training routine. I work hard to maintain a low body fat percentage while remaining highly conditioned with cardio workouts and heavy resistance weight training. The only supplement I take is Branch Chain Amino Acids (BCAAs) and I also drink whey protein shakes on most days. We are different and our bodies react in various ways but I don’t shy away from protein and it has always been an important part of my success in training both for and outside of the military. It is a key part of my ketogenic lifestyle and it has never negatively impacted my ability to remain in nutritional ketosis. For all my clients and those I help out the standard I always use for macronutrient guidance and associated meal planning is .8 grams of protein per pound of lean body mass. Remember, fat gives you energy on keto while protein keeps your body strong and functional.
- Dietary Guidelines For Americans 2015 -2020, Eight Edition. https://health.gov/dietaryguidelines/2015/resources/2015-2020_Dietary_Guidelines.pdf
- Table A7-1. Daily Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations, Dietary Guidelines for Americans 2015-2020 Eight Edition. https://health.gov/dietaryguidelines/2015/guidelines/appendix-7/
- Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fatty Acids, Cholesterol, Protein, and Amino Acids; Institute of Medicine of the National Academies, 2005. https://www.nap.edu/read/10490/chapter/1
- Westerterp, Protein intake and energy balaance, 2008. https://www.ncbi.nlm.nih.gov/pubmed/18448177
- Souza, Effects of 4 weight-loss diets differing in fat, protein, and carbohydrates on fat mass, lean mass, visceral adipose tissue, and hepatic fat: results from the POUNDS LOST trial, The American Journal of Clinical Nutrition, 2012. http://ajcn.nutrition.org/content/early/2012/01/17/ajcn.111.026328
- Halton, The effects of high protein diets on thermogenesis, satiety and weight loss: a critical review. 2004. https://www.ncbi.nlm.nih.gov/pubmed/15466943
- Westerterp, Diet induced thermogenesis, Nutrition and Metabolism, 2004. https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-1-5
- Manninen, High-Protein Weight Loss Diets and Purported Adverse Effects: Where is the Evidence?, 2004. https://jissn.biomedcentral.com/articles/10.1186/1550-2783-1-1-45
- Volek, Phinney, The Art and Science of Low Carbohydrate Living, 2011.
- Bosse, Dietary protein to maximize resistance training; a review and examination of protein spread and change theories, Journal of the International Society of Sports Nutrition, 2012. https://jissn.biomedcentral.com/articles/10.1186/1550-2783-9-42
- Phillips, Dietary protein for athletes: from requirements to optimum adaptation. 2011. https://www.ncbi.nlm.nih.gov/pubmed/22150425
- Phillips, Dietary protein for athletes: from requirements to metabolic advantage, 2006. https://www.ncbi.nlm.nih.gov/pubmed/17213878
- Nuttall, Regulation of hepatic glucose production and the role of gluconeogenesis in humans: is the rate of gluconeogenesis constant?, 2008. https://www.ncbi.nlm.nih.gov/pubmed/18561209
- Khan, Glucose appearance rate following protein ingestion in normal subjects, 1992.
- Wilson, Lowery, The Ketogenic Bible, 2017.