A Look at the Role of Protein and New Recommended Intakes

There seems to be a lot of buzz around consuming protein. Those advocating for increasing muscle mass are huge enthusiasts of increasing protein and I see protein EVERYTHING when I scroll through instagram. But protein isn’t praised just by those interested in growing muscle mass, there seems to be a growing consensus that increasing protein intakes is helpful for overall health. 

I thought it would be helpful to dive into what the science says regarding protein intake and what actual literature suggests rather than just taking people’s word for it (even people I highly respect).

Protein and its role in the body

So what is protein and what is it used for? Proteins are molecules made up of individual amino acids in varying configurations (depending on the protein). There are roughly 500 amino acids found in nature, but our bodies only use 20 of them. The 20 amino acids used by our body can be divided into two categories—essential and non-essential. The eleven non-essential amino acids can be made in the body from other amino acids and therefore don’t have to be consumed in our diet. Our bodies lack the enzymes necessary to make the other nine essential amino acids so they MUST be consumed through the diet (hence the term “essential”). The amounts of these essential amino acids in our diet and in our body are the limiting factor for protein synthesis (if our body needs to make a protein requiring one of these essential amino acids and it doesn’t have it, our body simply won’t be able to make the protein needed). In general, animal sources of protein are complete proteins, meaning they have all 9 essential amino acids, along with non-essential amino acids. There are a few plant sources of complete proteins (soy, quinoa, chia seed, etc), but for the most part, plant sources of protein will contain only some of the essential amino acids. This is why it is important to use multiple plant protein sources so that they can complement one another and provide the missing essential amino acids (such as combining beans with legumes).

Protein is used for MANY processes in the body. Lean muscle mass is probably the most recognized use for protein since muscle mass is made up of proteins. But protein plays a role in our immune system, gene expression, and hormones; and makes up cellular structures, hair, skin, and enzymes, which carry out every chemical reaction in our cells. Protein is a pretty big deal! If our intake of protein is inadequate to our needs, or is lacking in essential amino acids, our body’s processes will be halted. I also want to note the importance of eating enough overall calories. If we are not consuming enough energy, our bodies will utilize protein as a source of energy rather than using it as building blocks for the necessary structures/enzymes/hormones. We also know that protein takes longer to digest (compared to carbohydrates) and leads to increased fullness and satiety and can help with slowing down the digestion and absorption of carbohydrates, helping with blood sugar stabilization.

The role of protein in muscle growth

At all times, the body is tearing proteins down and building up new ones. We call this muscle protein breakdown and muscle protein synthesis. In order to build muscle mass (or “lean mass”), our net protein synthesis has to be greater than our protein breakdown. The ONLY way to have protein synthesis greater than breakdown is to supply adequate dietary protein. You can’t build something if you don’t have the necessary building materials. Strength training significantly stimulates muscle protein synthesis AND increases sensitivity to amino acid uptake, which is why fueling after a workout is so important (utilize that increased synthesis!)

You can see why those promoting building muscle mass also promote eating large amounts of protein. But here’s the deal, there’s a limit to how much your body can utilize and incorporate into muscle synthesis. A study by Stokes et al. suggests that muscle protein synthesis is a saturable process and that there is no benefit to having a higher intake of amino acids than the muscles can use.(1) The authors reported that muscle synthesis was negligibly increased above 20 g protein after a workout, with no difference at 40 g protein (compared to 20 g). Our bodies only use about 10% of the amino acids consumed after a workout (2.2 g of 20 g protein bolus in this case), meaning that it is important to be consuming protein regularly throughout the day in order to build muscle mass. Eating one large meal of protein after a workout won’t be as effective as eating more moderate protein meals/snacks throughout the day since the remainder of the protein would be used for energy rather than muscle synthesis or body protein needs. It’s also important to note that the body sends amino acids to the muscles AFTER the gut cells and liver have used what they need. If you are not consuming enough protein regularly throughout the day, the gut and liver are preferentially going to use the amino acids rather than sending them to your muscles. 

So how much should we be consuming? New recommendations

When I was in school, I was taught that the average person needs 0.8 g/kg/day (0.36g/lb/day) in order to meet body protein needs. This was determined using the nitrogen balance method. New advances in technology suggest that the indicator amino acid oxidation (IAAO) method may be a more accurate test for determining protein needs. It takes into account essential amino acids being a limiting factor to amino acid utilization in the body (remember, if your body lacks the essential amino acid it needs for building, it won’t build that protein and instead will just use the amino acids for energy production). This new IAAO method suggests that previous protein recommendations were far too low. (2)

I found multiple studies suggesting new increased protein recommendations based on the IAAO method. They ranged from 0.91-0.99 (0.41g-0.45 g/lb/day) to 1.5-2.2g/kg/day (0.68-1g/lb/day) for general health and wellbeing (2,3,4). Additionally, the study by Stokes et. al recommends intakes for those wanting to build muscle mass to be 0.73-1 g/lb/day. (1) I know that's a lot of numbers!! 🤪 Just know that we need more protein than previously thought. I have seen a lot of recommendations online for calculating protein needs starting at 1 g/lb (gram per pound) and going beyond. And although the recommendations are higher than before, I found no literature that supported benefit over 1 g/lb (except for in extremely low calorie diet trials, which I don’t support and isn’t relevant to this article). The previous recommendations were 0.7 g -1.2 (even all the way to 1.5) grams of protein per kilogram and I’m curious if people saw those recommendations and thought they were per pound. Hence the common recommendations of over 1 gram of protein per pound. Just speculation!

In the past, I believed that too much protein was hard on the kidneys , but it seems there is now no evidence to support that claim in the general, healthy population (I’m constantly have to learn new information too!)(4). So eating above that 1 g/lb isn’t likely to cause any harm, but I would argue that eating more than that (or more than 35% total calories from protein) would be at the expense of eating other necessary food groups. Is it really beneficial/helpful to be stuffing protein, but then be too full to consume adequate fruits, vegetables, and other plants? Additionally, consuming that much protein can be difficult and unenjoyable/unappetizing. I’m a firm believer that a healthy way of eating and interacting with food is one that is full of enjoyment and satisfaction. Eating at the higher end of the recommendations and above may simply be unsustainable or set you up for bingeing because of feeling unsatisfied. So yes, maybe try increasing your protein intake or increasing awareness of how much you’re taking in, but not at the expense of your relationship with food. ☺️

So as a recap:

• Dietary protein is important for stabilizing blood sugar, providing satiety, providing the building blocks for many structures/processes in our body, and building muscle mass.

• Protein synthesis in the body is limited by the essential amino acids. It is important to be consuming adequate complete proteins or a combination of incomplete proteins to ensure the body can use amino acids for protein synthesis instead of energy production. 

• For general health, aim anywhere from 0.45-1g/lb/day. (150 pound individual would aim for 59-150 grams of protein/day). I’d aim for the middle range if increasing muscle mass isn’t your goal.

• If you’re wanting to build muscle mass, aim for 0.73-1g/lb/day (150 pound individual would aim for 110-150 grams of protein/day)

• There isn’t evidence to suggest that eating too much protein is harmful for the kidneys for the general population, but it could be at the expense of other important food groups/nutrients (like fiber or phytonutrients)

• Keep in mind enjoyment and satisfaction. .

If you are needing help learning how to incorporate more protein rich foods into your diet or wanting to increase muscle mass, but are having difficulty, reach out and we can talk about working together to accomplish your goals.

I’d love to hear any thoughts you have in the comments!

References:

1 Stokes T, Hector AJ, Morton RW, McGlory C, Phillips SM. Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training. Nutrients. 2018;10(2):180. Published 2018 Feb 7. doi:10.3390/nu10020180.

2 Elango, R., Ball, R. O., & Pencharz, P. B. (2012). Recent advances in determining protein and amino acid requirements in humans. British Journal of Nutrition, 108(S2). https://doi.org/10.1017/s0007114512002504  

3 Paul B. Pencharz, Rajavel Elango, and Robert R. Wolfe. Recent developments in understanding protein needs – How much and what kind should we eat?. Applied Physiology, Nutrition, and Metabolism. 41(5): 577-580. https://doi.org/10.1139/apnm-2015-0549

4 Stuart M. Phillips, Stéphanie Chevalier, and Heather J. Leidy. 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

Your Dairy Questions Answered

This recap was created in collaboration with Midwest Dairy as part of the dairy community’s Undeniably Dairy campaign . I was compensated for my time, but the content and opinions included are my own.

Back in September, I had the privilege of visiting a dairy farm in Chicago. I loved getting to see where our milk actually comes from and what the process of caring for and milking cattle looks like. I was able to meet the dairy farmers who own and run it, as well as ask them any questions I had. It’s really cool being more connected to our food supply.

And if you follow me on IG, you may have noticed that I recently did a Q&A regarding dairy on my stories. I addressed all of your questions, as well as a few details I thought were important to touch on. If you missed it, you can see my answers on my highlight reel HERE.

If you aren’t on Instagram, are a visual processor, or simply prefer cliff notes, here is the shortened version of what I discussed:

Can dairy cause acne?

1. Diet and acne is still a controversial topic, with conflicting information.

2. There is research that supports a diet high in high-glycemic foods may worsen acne. Additionally, studies have shown dairy and acne to be weakly associated. Skim milk had a stronger association with worsened acne than whole milk. (1)

3. Milk can cause rashes or eczema, but is more likely related to a milk allergy (so get tested!).

Is it unhealthy to drink whole milk? What about the saturated fat content?

• A research study showed higher intakes of saturated fat from dairy was associated with decreased risk of cardiovascular disease.

• Full fat dairy has been associated with decreased risk of metabolic syndrome. (2)

• Full fat dairy leads to increased satiety and fullness.

• Full fat dairy can help with blood sugar stabilization (fat is slower to digest, so your blood sugar doesn’t spike as much).

Don’t the hormones given to the cattle pass into milk? Are they dangerous to our health?

• Dairy cows used to be given rBST to increase milk production. Consumers didn’t like this, so the majority of dairy farmers no longer use this and sign agreements not to.

• rBST is digested into individual peptides and amino acids (so it’s not absorbed into the bloodstream as a hormone). Additionally, our body lacks receptors for this hormone, so it can’t bind to anything to elicit a response.

• There are naturally occurring hormones that pass into the milk (just like hormones pass from human moms into their breastmilk!), but the amount passed through is not significant.

• Addition for you guys (not in my videos): 1 8-oz cup milk has up to 2.2 ng estrogen; 1 Tbsp flax has 26,556.6 ng estrogen; ½ cup pinto beans has 154,800 ng estrogen; 3/4 cup tofu has 34,050,000 ng estrogen. A prepubescent child produces 41,000 ng/day; an adult male produces 136,000 ng/day; a non-pregnant woman produces 513,000 ng/day; and a pregnant woman produces 19,600,000 ng/day. (3,4)

I heard dairy is not easily digestible, so it’s not meant to be eaten?

• It’s true that some people have a difficult time digesting lactose in dairy, and for those, I suggest taking lactaid, drinking lactose free milk, or eating low lactose products like hard, aged cheeses or Greek yogurt.

• There are a lot foods our bodies may have a difficult time digesting (high fiber foods, fats, proteins), but that doesn’t mean we make a blanket statement that no one should eat them. If that were the case, gas-producing veggies like broccoli, cauliflower, and Brussels sprouts would be nixed. ;-)

Is dairy nutritionally necessary?

• Dairy is not necessary in order to have a healthy, nutritious diet (or else people with dairy allergies would be in trouble!), BUT it is a very convenient and affordable source of great nutrition. Dairy is a wonderful source of protein, carbs, fat, calcium, vitamin A & D (fortified dairy), potassium, and phosphorous.

• Additionally, dairy is delicious (in my opinion), and eating foods we enjoy is helpful for having a healthy relationship with food and having a nutritious food intake.

Greek yogurt for lactose intolerance?

• For those with lactose intolerance, Greek yogurt (as well as hard, aged cheeses) can often be well tolerated, as the majority of the lactose is discarded along with the whey when strained.

• For those with high sensitivities to lactose, some companies actually make lactose free yogurt, including Yoplait and Green Valley Creamery.

Milk for lactose intolerance if I don’t like the taste of soy milk?

• Try lactose free milk, such as Lactaid, Fairlife, or Horizon!

Calf care concerns

• Pregnant cows are separated from the herd and not milked for 2-3 months before giving birth.

• While it varies from farm to farm, it is standard practice for the calf to be separated from the mom within 24 hours after delivery for the safety of the calf (to prevent infection from eating or lying in mother’s manure, some cows don’t pay attention to their calves, etc). Farmers ensure the calves are given quality colostrum (quality colostrum=increased chances of a strong immune system) and then milk either from the mom directly or through a bottle .

• The calf is separated from the herd for the first 3 months in a dry, clean place to ensure the calf is healthy and growing properly.

• Cows’ well-being is of upmost importance to the dairy farmer. Sick cows are expensive to treat, and unhappy or stressed cows produce less milk. Less milk=lower profit.

Organic vs. conventional dairy

• Certified organic dairy farms have to uphold set standards (5): only organic fertilizers and pesticides on crops; at least 120 days of access to pasture (and then supplemented to ensure a balanced diet); and if an animal is given antibiotics, it must be sold.

• The only nutritional difference is that organic milk is higher in omega-3 fatty acids and lower in omega-6 fatty acids. However, milk (organic or not) is not a significant source of omega-3s. Some companies do fortify their milk with DHA, so if milk is your go-to source for omega-3s, opt for a fortified product.

Antibiotics in milk?

• When a cow is given medications or antibiotics for conditions such as mastitis, the cow’s milk is thrown away and not saved for consumption.

• Shipments of milk are checked for antibiotic residue before leaving the farm as well as at least one other time in the manufacturing process. If antibiotics are found in the milk, the entire tank is thrown away at the expense of the farmer. (6)

• Added (not on my videos): Testing for antibiotics have only gotten more stringent over time. More rigorous testing=higher quality assurance for the consumer. (7)

If your interested in what a dairy farm looks like and how it functions (but can’t go visit one in real life), you can check out this online farm experience here.

Sources:

1. Dairy and acne https://www.sciencedirect.com/science/article/abs/pii/S0190962209009670

2. Full fat dairy and Metabolic syndrome https://academic.oup.com/jn/article/146/1/81/4616088

3. Estrogen found in flax seed https://www.salon.com/2014/04/13/4_otherwise_healthy_foods_crammed_with_estrogen_partner/

4. Estrogen found in various foods and produced by humans: http://www.iowabeefcenter.org/information/IBC48.pdf

5. Certified organic requirements https://www.ams.usda.gov/sites/default/files/media/Dairy%20-%20Guidelines.pdf

6. https://ww6)w.fda.gov/media/111169/download

7. antibiotic testing resources https://pubs.rsc.org/en/content/articlelanding/2009/an/b817836d/unauth#!divAbstract ; https://www.sciencedirect.com/science/article/abs/pii/S0165993609000776 ; https://www.health.state.mn.us/diseases/antibioticresistance/animal/truthmilk.pdf ;

Maternal intake and breastfeeding

So I’ve been trying to write this blog post for several weeks now. But a certain babe has kept me from having the free time and mental space to actually do it. 🙄Such is life right now…

When it comes to pregnancy and breastfeeding, there is a LOT of pressure put on moms to have the perfect diet in order to provide the best nutrition for their growing babies. But can I be honest? That’s way too much pressure for me to handle. Yes, during pregnancy and now breastfeeding I am providing all of the nutrition for my baby. But getting it “perfect” is just too much pressure for anyone and can create a lot of fear, guilt, or shame. Besides, the opinion on the optimal diet changes from one person to the next (sounds a lot like the rest of diet culture). During pregnancy I just focused on eating what I wanted, when I wanted it, and as much as I needed. I didn’t focus on certain macros or food groups. I trusted that my body would lead me towards what it needed to grow my baby.

And this is the perspective I have taken into breastfeeding. Sure, I focus on drinking enough water and eating enough food, but it’s not difficult for me since my body is constantly telling me to eat and drink. 😂 However, since I’m in this stage of life and there is a lot of well-meaning (but stressful) advice out there for breastfeeding mothers, I decided to look into the research about breast milk and how maternal diet impacts it. I hope you find this post helpful if you are in this stage of life! Also, this post is not to convince you to breastfeed your baby. I completely understand that this is not always feasible and believe that “fed is best.” Please do not let this post shame you if breastfeeding was not feasible for you or if you chose to use formula instead.

Here’s a little bit of background information on breast milk. First, it contains a variety of growth factors, hormones, enzymes, immune system factors, macronutrients (protein, carbs, and fat), and micronutrients (vitamins and minerals). It’s caloric content varies from the beginning of the feeding to the end of a feeding, feeding to feeding, and even day to day. Lactose (a type of carbohydrate) is the most abundant macronutrient and is the most stable between feedings and from mother-to-mother. Fat content is what creates the most variability in composition and caloric content. It is more concentrated as the feeding goes on and varies in type depending on number of pregnancies, when your baby was born, how far you are postpartum (our body uses up our reserves of a certain type of fatty acid), and the types of fats you are consuming. Although the vitamins and minerals present in breast milk are in smaller quantities than in formula, it is actually more easily absorbed and utilized in the body. Basically, breast milk is constantly changing based on a variety of factors.

How does one’s food intake impact the nutrition available in milk? Can we increase the fat or vitamin/mineral content available in our milk? Here’s what we know—mom’s diet has some effect on breast milk composition, but probably not as big of an impact as we would like to think (fortunately or unfortunately). Neither mom’s food intake nor body composition are going to impact carbohydrate or protein content in the milk. But research does show that there is a correlation between maternal fat intake and breast milk fat composition. It doesn’t impact how much fat is present, rather the type of fat present in the milk. Some people have fattier milk (and therefore more calorically rich milk) than other moms, but I didn’t find any research that definitively answered the question of why there is so much variability among moms. Fortunately, volume of milk is important for infant growth rather than amount of fat or concentration of calories. This means that if you are feeding your baby often enough, they are going to be well-fed, even if your milk is on the lower side of fat/calories. (takes off some of the pressure, right?) A major type of fat that is impacted by maternal intake is that of DHA, a type of omega-3 that is important for brain development. Because of this information, I had been focusing on eating more plant sources of omega 3s (walnuts, flax seed, etc), but found out that the conversion of omega 3s into DHA in reality is pretty poor from these sources. The best sources are actually from fatty fish or a supplement. My recommendation? Take a prenatal vitamin with DHA 😉 (and eat some seafood if you like it!).

When it comes to vitamins and minerals for milk, food intake of those nutrients obviously creates the availability of them for milk. But just as we don’t have to consume 100% of our daily needs each day for our body (nutrition status is about overall intake over several days, not just one meal or day), we don’t have to consume 100% of all the vitamins or minerals every day for it to be present in adequate amounts in our milk. Research shows that our milk is incredibly resilient despite inadequate intakes, and slowly decreases in milk if it is not readily available from our diet. If we are lacking in certain nutrients day after day, our bodies will then use our own body’s reserves to feed our babies. Once that is used up, our milk concentration of those nutrients will suffer.

I know that breastfeeding is touted as THE way to help new moms lose their baby weight. There is a lot of pressure for moms to quickly return to their pre-baby body, which often results in moms trying to reduce food intake and increase exercise along with breastfeeding to get rid of that weight. In reality, research doesn’t support this. Yes, there are some moms who lose weight breastfeeding, but there is a large majority of the population who don’t. It makes sense that our bodies would hold onto extra energy if they are having to constantly supply energy for another human. It’s self-preservation. And although our milk supply and composition are fairly resilient regardless of our food intake, if we are not consuming enough food, it IS going to impact our ability to feed our babies as well as our ability to take care of ourselves.

I find it really comforting and reassuring that I don’t have much control over my breast milk composition and nutrient quality. Let’s take the pressure off of ourselves! But that doesn’t give us the excuse to underfeed our bodies in an attempt to make them smaller. Breastfeeding takes a big toll on mother’s nutrition status and requires that we feed our bodies regularly and adequately (and again, I recommend a prenatal supplement). We want to have the energy to take care of our babes, the available nutrition for our own bodies to create proper brain chemistry (motherhood is hard enough without having a lack of serotonin from underfeeding our bodies!), and the brain space to fully be present rather than thinking/worrying about food all the time.

I’d love to hear from you what your favorite breastfeeding snacks are (the hunger is no joke…)!

Sources:

http://www.asklenore.info/breastfeeding/resources/mysteries.shtml

https://www.nap.edu/read/1577/chapter/1#xi

https://www.sciencedirect.com/science/article/pii/S0952327815000307