A Closer Look at Protein for Improved Body Composition—Are You Getting Enough?
Lean muscle mass plays an outsize role in overall health and becomes even more critical as we age. The elemental building blocks for this tissue are supplied by protein intake, but how much protein do women really need? This article explains how protein is metabolized and how demand changes with your hormones to help you audit your intake and make sure you’re getting enough.
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The guidance included in this post is intended for active women participating in some form of regular resistance training and exercise.
Information in this post and on this web site is provided for informational purposes only. The information is a result of practice experience and research by the author. This information is not intended as a substitute for the advice provided by your physician or other healthcare professional or any information contained on or in any product label or packaging. Do not use the information on this web site for diagnosing or treating a health problem or disease, or prescribing medication or other treatment. Information and statements regarding dietary supplements have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease. Always speak with your physician or another healthcare professional before taking any medication or nutritional, herbal, or homeopathic supplement, or using any treatment for a health problem.
Getting more is only part of the protein picture—consuming a complete protein profile is critical for body composition. When amino acid deficiencies exist, the body breaks down muscle as the reserve supply even if total protein is sufficient.
Short on time? Here are the key takeaways:
Protein comprises amino acids that are required for countless essential functions throughout the body and can be used as a last resort for energy.
Amino acids account for 20% of total body mass and 50% of solid body mass.
For moderately active menstruating women, protein demand is significantly higher than the RDA.
Getting more is only part of the protein picture—consuming a complete protein profile is critical for body composition. When amino acid deficiencies exist, the body breaks down muscle as the reserve supply even if total protein is sufficient.
Protein can only help build muscle in the presence of a stimulus—higher protein intake must be paired with resistance to see favorable changes in body composition.
During the low-hormone follicular phase, active females need between 0.5 and 0.8 grams of protein per pound of bodyweight per day—comprising 30% of total calories—for general muscle growth, repair, and strength adaptations. [6]
Dr. Stacy Sims recommends bumping this up to between 0.8 and 1 gram of protein per pound of body weight and 35% of total calories in the high-hormone phase to mitigate the catabolic effects of progesterone. [1a]
Estrogen hormones stimulate muscle growth and when levels decline during perimenopause, a new stimulus must be introduced to maintain muscle mass.
In perimenopause and beyond, add resistance and high-intensity training to your routine and increase protein intake to between 0.8 to 1 grams per pound of body weight.
What is Protein?
Protein supplies amino acids which make up 20% of our total body mass and are responsible for countless essential functions in the body and brain.
Protein is one of the three macronutrients that the body requires in large amounts for energy—the other two being carbohydrate and fat. Macros supply the calories necessary to support every system in the body and keep you active. While fad diets might promote severely limiting an entire category of macronutrients, we must consume all three to function. Carbs and fat tend to get a lot of attention as being either good or bad. Protein however, is often overlooked or only partially understood and tends to be deficient in menstruating women. Though too much protein can lead to weight gain or liver and kidney distress, most of us have room to add more of this macronutrient into our diets.
Before you start piling your plate with protein, it’s important to understand how protein is metabolized, how demand changes with your cycle and activity level, and how different sources compare.
The Diet Darling of Macronutrients
All three macronutrients—carbs, fats, and protein—can be broken down and used as energy. Carbohydrates provide glucose for immediate use, fats break down into fatty acids for a more slowly released supply, and when metabolized, proteins break down into amino acids which must go through an additional step before being converted into usable energy. This is why protein differs from carbohydrate and fat in that its primary function isn’t to provide energy and it generally only answers this call when the other two macronutrients are lacking.
So what is protein’s primary role? The amino acids from protein are not only used to build muscle and other cellular structures, but to synthesize other proteins that are essential to vital functions. Additionally, amino acids are the precursors to key neurotransmitters like serotonin, melatonin, dopamine, and norepinephrine which means they influence cognition and brain performance. The availability of amino acids can affect everything from sleep and hormone secretion to blood pressure and mood. [3]
Dr Stacy Sims lovingly refers to protein as a diet darling because it supports a variety of systems with less caloric load than carbs and fats. [1] Note: carbs and protein both have 4 calories per gram, but protein requires more energy to digest so the net calories are less.
To highlight a few of the benefits, protein:
helps build and maintain muscle mass
improves basal metabolic rate
helps burn more body fat
contributes to hormone regulation
supports weight loss [2]
reduces blood sugar swings
improves satiety and decreases cravings
helps recovery and repair after exercise
supports the immune system
Takeaway → Protein comprises amino acids that are required for countless essential functions throughout the body and can be used as a last resort for energy. When dietary protein is deficient, the body breaks down muscle to access a reserve of amino acids and carry out necessary functions.
The Complete Protein Conundrum—Not All Protein is Created Equal
By now, you’ve probably heard the recommendation for increasing protein in more places than one. Not to mention the barrage of marketing on food labels that boast the latest plant sources and high protein grams per serving. However, not all sources are created equal and getting more is only part of the whole protein picture.
Essential Amino Acids and Complete Proteins
As mentioned above, protein comprises amino acids and when broken down it supplies the essential building blocks for nearly every physiological function in the body and brain. What’s tricky is that only 11 of these amino acids can be manufactured in house. The other 9, termed essential amino acids (EAAs), must be provided through diet and a protein is only considered complete when it contains all 9.
You Need The Whole Amino Acid Crew
We need the full spectrum of essential amino acids to preserve muscle mass, support enzyme production, regulate hormones, improve cognition performance, stabilize mood, and optimize metabolism.
In a recent podcast interview, SEO of Kion Angelo Keely likened the essential amino acids to a construction crew with leucine being the general contractor and the remaining 8 EAAs being the subs. [10] If the GC is absent when the workers show up, no building is happening that day. If one of the subs doesn’t show, you might have walls, but no plumbing. What’s worse is when you only have a partial crew, workers might get pulled from other jobs i.e. muscle, to complete the critical path tasks.
The bottom line? Incomplete proteins cannot be consumed in isolation and you must choose from a variety of sources to create a complete protein profile. For example, did you know that the latest collagen protein trend is typically not a complete source? If you consume a collagen supplement, but neglect the remaining amino acids that complete the protein, chances are you won’t see the results you’re looking for.
Challenges for A Plant-Based Diet
Meeting your complete protein demand is easier with a diet that includes animal protein because most meat, fish, and dairy include all 9 essential amino acids. The task is challenging, but not impossible when you’re getting protein from plant sources. The key is to include a variety of foods that include all amino acids, particularly those high in leucine for muscle building and tryptophan for cognitive function. Don’t worry though, it is not imperative to aggregate complete proteins with every meal—they can be combined cumulatively throughout the day.
Below is a reference list of complete plant proteins as well as those high in leucine and tryptophan.
Complete Plant Proteins
quinoa
seaweed
leafy greens
soy
oats
sunflower seeds
buckwheat
lentils
High Leucine Content
watercress
hemp
kidney beans
soybeans
chia seed
peanuts
pumpkin seeds
spirulina
High Tryptophan Content
pumpkin seeds
mushrooms
tempeh
lima beans
broccoli
amaranth
spinach
peas
Takeaway → We need a full spectrum of amino acids to preserve muscle mass and carry out essential functions in the body and brain. There are 9 essential amino acids (EAAs) that cannot be produced by the body and must be consumed as protein. Furthermore, a protein is only considered complete when it contains all 9 EAAs. Consuming a complete protein profile throughout the day is imperative for body composition—when deficiencies are present, the body breaks down muscle as the reserve supply even when total protein intake is sufficient.
Meeting Protein Demand
The recommended dietary allowance (RDA) for protein is 0.36 grams per pound of body weight per day and tends to be insufficient as a baseline for adults who exceed a sedentary lifestyle. [5] With a predisposition to metabolic flexibility and carbohydrate sparing, this modest intake may even be detrimental for active menstruating women. [4]
Too Little Leads to Muscle Wasting and Brain Fog
As described above, protein provides the amino acids that keep your body and brain functioning. When sufficient amino acids are not available in the food we eat, the body’s backup plan is to break down muscle for a reliable reserve.
A diet lacking protein can lead to feeling flatlined during workouts because the carbohydrates consumed aren’t used as intended for energy, but instead get used for muscle repair. Moreover, when this happens in the already catabolic luteal phase, we get stuck in a cycle of muscle wasting and unfavorable body composition even if the scale tells a different story. With less muscle mass, your weight may go down, but fewer calories are burned at rest and with lower circulating amino acid concentration, cognitive performance declines.
How Much Is Too Much?
The body is very adept at putting protein to good use. When supply exceeds demand, the liver readily metabolizes dietary protein and directs amino acids to wherever they can be used. [9] That being said, many protein sources are high in calories and fat and as with any nutrient surplus, that which goes unused is generally stored in adipose tissue (fat cells).
Additionally, protein can only help build muscle in the presence of a stimulus. This means that your higher protein intake must be paired with some form of resistance training to see favorable changes in body composition. Consider gradually increasing your protein intake on resistance training days and timing it around sweat sessions—specific guidance is provided below.
Hormone Influences On Protein Demand
The key hormones that regulate the endogenous menstrual cycle are estrogen and progesterone. When the relative concentrations of each change throughout the month, a series of metabolic shifts occur that influence how our bodies use macronutrients to fuel essential functions and exercise. [4] For protein considerations, we’ll look at three key phases: low hormone, estrogenic, and high hormone.
Low-Hormone Phase: Menstruation and Early Follicular
estrogen ↓ progesterone ↓
During the low-hormone phase, women’s bodies access and store carbohydrates well and we experience better recovery. This is likely when we are hitting higher intensity, exerting more power, and lifting heavier weight. With a lower level of hormones, we experience less catabolism (tissue breakdown) and less central nervous system fatigue (mood perturbations). As with the other phases of the cycle, it’s important to focus on fueling for your activity level when it comes to protein.
Protein Considerations to Support Training in the Low-Hormone Phase
In general, 0.5–0.8 grams of protein per pound of body weight per day comprising 30% of total calorie intake will support moderate activity and workouts less than 90 minutes in duration. [6]
Spread protein intake across several meals throughout the day and consider a snack with 20-30 grams of protein pre- and post-workout for lean muscle development and maintenance.
Workout fuel is particularly important for morning workouts because we wake in a fasting catabolic state.
Estrogenic Phase: Late Follicular and Ovulatory
estrogen ↑ progesterone ↓
As we enter the ovulatory phase around mid cycle, estrogen hormones rise and progesterone remains suppressed. While protein intake can stay in the same range as the low-hormone phase, there are a few important metabolic changes to be aware of.
Estrogen is an anabolic hormone which supports muscle growth and adaptation. This hormone also tends to boost energy levels and may give you more power during workouts. On the flip side, estrogen has a reproductive mission and shuttles all the good stuff to the nutrient-dense endometrium in preparation for pregnancy. This hormone promotes carbohydrate sparing which impedes our quick access to muscle and liver glycogen for energy—we rely more on slow-burning fat for fuel or a greater spike in cortisol to get the job done.
This means you might want to start dialing back intensity after the estrogen surge and be sure to incorporate pre- and post-workout fuel that is high in protein to top off the tank in the late follicular and ovulatory phases.
Protein Considerations to Support Training in the Estrogenic Phase
See the protein recommendations from the low-hormone phase and be sure to incorporate a post-workout snack within 30 minutes to stabilize blood sugar, reduce inflammation, and boost immunity.
High-Hormone Phase: Luteal
estrogen ↑ progesterone ↑
After ovulation, the ruptured follicle that released a mature egg collapses and begins producing progesterone. Paired with elevated estrogen levels, we now enter the high-hormone phase. During this phase, there is a marked shift toward breakdown and inflammation. Basal metabolic rate increases and protein oxidation is greater during exercise and at rest. [7] Plus, higher levels of circulating estrogen cross the blood-brain barrier which can cause mood disruptions.
During this demanding time in the cycle, any additional stress produced by exercise can increase cortisol and chip away at lean muscle mass without a corresponding upgrade in nutrition. This is when added protein is necessary to supply sufficient amino acids for central nervous system support and provide the building blocks that facilitate muscle-protein synthesis.
Protein Considerations to Support Training in the High-Hormone Phase
Focus on proteins high in muscle-building leucine—meat, dairy, ricotta cheese, navy beans, pumpkin seeds, and eggs—to combat the breakdown effects of progesterone and mitigate mood disruptions.
Increase protein intake to 0.8-1 grams per pound of bodyweight per day and 35% of total calories. [1]
As in the low-hormone phase, tailor protein timing to your training. Aim to bookend your training sessions with 20-30 grams of protein.
Takeaway → For moderately active menstruating women, protein demand is significantly higher than the RDA. During the low-hormone follicular phase, active females need between 0.5 and 0.8 grams of protein per pound of bodyweight per day—comprising 30% of total calories—for general muscle growth, repair, and strength adaptations. [6]
→ Dr. Stacy Sims recommends bumping this up closer to 1 gram and 35% of total calories in the high-hormone phase to mitigate the catabolic effects of progesterone. Stay on the high end of these recommendations if you’re very active with regular resistance training and on the low end for moderate activity levels.
Considerations for Perimenopause and Menopause
As we age, we become more sensitive to carbohydrates when estrogen levels decline. This means we’re more likely to store body fat and it becomes more difficult to build muscle. In order to set ourselves up for greater longevity and favorable body composition later in life, it’s best to start with a healthy baseline of lean muscle mass.
While it’s never too early to start implementing strategies that will improve lean muscle mass for long-term health, the transitionary period known as perimenopause is an opportune time for intervention. A recent study demonstrated that women in perimenopause were most likely to experience the onset of unfavorable body composition and metabolism when compared with pre- and post-menopause. [8] When you begin experiencing cycle irregularities and symptoms of this transition, consider a few key shifts:
Estrogen is anabolic and promotes muscle-protein synthesis (growth). When this hormone begins to decline in perimenopause, you must introduce a new stimulus to maintain lean muscle mass.
If you haven’t already, add more resistance to your training. Lift heavy things to produce the stimulus needed to build and maintain muscle as hormone levels decline.
Favor intensity over volume. Add short bursts of max exertion to your sessions to support fat-burning metabolism and insulin sensitivity.
Finally, you guessed it, add more protein to your diet. Aim to get around 0.8 to 1 grams of protein per body pound of bodyweight to combat muscle decline and favor foods high in the amino acid leucine. [1b]
That sounds like a lot, I know, but it doesn’t have to happen all at once. Increase intake gradually over a period of several months and adjust according to your activity level. Consider adding a complete protein supplement between meals to avoid the excess calories and fat that sometimes come with high-protein foods.
Takeaway → Estrogen hormones stimulate muscle growth and when levels decline during the menopause transition, you must add stimulus to maintain muscle mass. Add resistance and high-intensity training to your routine and increase protein intake. Don’t wait until menopause hits to implement these strategies, start now.
References
Sims, Stacy T. ROAR: How to Match Your Food and Fitness to Your Female Physiology for Optimum Performance, Great Health, and a Strong, Lean Body for Life. Rodale.
1a. The Betty Rocker Show (Host), (2021), Season 2 Episode 3 “Eating and Training with Your Cycle Part 1 With Dr. Stacy Sims, https://thebettyrocker.com/eating-and-training-with-your-cycle-part-1-with-dr-stacy-sims/
1b. Sims, Stacy T. “The Athlete’s Guide to Menopause,” Oustide Online, (2020), https://www.outsideonline.com/health/training-performance/menopause-exercise-tips/Weigle, D. S., Breen, P. A., Matthys, C. C., Callahan, H. S., Meeuws, K. E., Burden, V. R., & Purnell, J. Q. (2005). A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. The American journal of clinical nutrition, 82(1), 41–48. https://doi.org/10.1093/ajcn.82.1.41
Fernstrom, J. D. (1994). Dietary amino acids and brain function. Journal of the American Dietetic Association, 94(1), 71–77. https://doi.org/10.1016/0002-8223(94)92045-1
Hackney A. C. (2021). Menstrual Cycle Hormonal Changes and Energy Substrate Metabolism in Exercising Women: A Perspective. International journal of environmental research and public health, 18(19), 10024. https://doi.org/10.3390/ijerph181910024
Phillips, S. M., Chevalier, S., & Leidy, H. J. (2016). Protein “requirements” beyond the RDA: implications for optimizing health. Applied Physiology, Nutrition, and Metabolism, 41(5), 565–572. https://doi.org/10.1139/apnm-2015-0550
Mercer D, Convit L, Condo D, Carr AJ, Hamilton DL, Slater G, Snipe RMJ. Protein Requirements of Pre-Menopausal Female Athletes: Systematic Literature Review. Nutrients. 2020; 12(11):3527. https://doi.org/10.3390/nu12113527
Draper CF, Duisters K, Weger B, Chakrabarti A, Harms AC, Brennan L, et al. Menstrual cycle rhythmicity: metabolic patterns in healthy women. Sci Rep. 2018;8:14568 Available from: http://www.ncbi.nlm.nih.gov/pubmed/30275458
Gould, L. M., Gordon, A. N., Cabre, H. E., Hoyle, A. T., Ryan, E. D., Hackney, A. C., & Smith-Ryan, A. E. (2022). Metabolic effects of menopause: a cross-sectional characterization of body composition and exercise metabolism. Menopause (New York, N.Y.), 29(4), 377–389. https://doi.org/10.1097/GME.0000000000001932
Liu X, Wang H, Liang X, Roberts M.S. “Chapter 30 – Hepatic Metabolism in Liver Health and Disease.” Liver Pathophysiology. March 2017. https://www.sciencedirect.com/science/article/pii/B9780128042748000308
The Align Podcast (Host), (2022), Angelo Keely: Protein Hacks for Muscle Growth, Supplementing Amino Acids, the Downside of Vegan Protein, https://www.alignpodcast.com/episodes/angelo
