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

Mommy and Me Smoothie

This recipe was created in collaboration with Midwest Dairy. I was compensated for my time, but the content and opinions included are my own. 

You guys!! How is my baby starting to eat solids already?! WHERE has the time gone? Surely I don’t have a 6+ month year old. 😮 But alas, I DO. We are in the process of introducing new foods to sweet Harlow girl and allowing her to explore new flavors and textures. Something I forgot about is ALLLLL the messes created in this season. I love how relatively clean Camden is eating at the table. His food stays on his plate and I rarely have to clean his hands or face afterwards. There is just SO much cleaning that now has to be done—cleaning the high chair table, cleaning the bibs, washing out the rags we use to clean food off of her, and increased laundry with avocado and other food stains. 🥴 Woof.

With Camden, we used the baby led weaning process for introducing food to him. Pureed baby foods is a relatively new thing and before then, people were giving their babies the food they were eating. We liked how much cheaper and easier it was to be able to just give him the food we were eating (with a few modifications). It’s not for everyone, but we really liked it and how it encouraged independence and self-regulation with food. 

One of the first foods I offered Camden was plain greek yogurt with peanut butter mixed in and have done the same with Harlow. Greek yogurt is a great source of protein and fat as well as key vitamins and minerals, so I feel like it has a great nutritional bang for its buck. And surprisingly, recommendations for introducing high allergenic foods like dairy, nuts, and shellfish have changed from waiting until after 1 years old (for dairy, later for other allergens) to introducing it earlier in order to prevent risk of developing an allergy (if you or your family has a history of allergies, these recommendations are a little different—so research this and ask your pediatrician before you start introducing those foods to your little ones. The purpose of this post is not on baby led weaning or allergies with babies). 

In our current culture, there seems to be a lot of fear regarding giving our children dairy (or even ourselves!). If you have questions about the safety or nutrition of dairy, check out the Q&A I did last year on it. You can also check out the blog post here. Before having Camden, I did my own personal research on common concerns regarding dairy and feel VERY confident giving it to my children. Dairy isn’t a necessity, but I love how it packs a punch in terms of nutrition for a relatively low cost. And let’s be real, it’s just so stinking delicious. Recommendations are for babies to be at least one year old before introducing cow’s milk to drink (babies should be drinking formula or breastmilk until then), but other sources such as yogurt, cottage cheese, or cheese are recommended. Additionally, milk IN things is just fine—just not straight in a bottle or cup because of the low iron content in cow’s milk.

I mean, come on! Look at that creamy texture!!

Dairy has been a major source of protein for Camden throughout the past two years, because well, toddler preferences against meat and beans. 🤪 When planning out his meals, and eventually Harlow’s, I aim for a source of protein, fat, carbs, and then a fruit or vegetable. Oftentimes, I use cheese or Greek yogurt as both the protein and fat because Cam loves them. He has also been a big fan of smoothies for quite awhile. As a baby and even more so now, it’s a VERY easy and convenient way for him to get in fruits and veggies as well as some protein and fat. The smoothie recipe below is our basic recipe that you can modify for your tastes and preferences. Switch up the fruits, add frozen steamed zucchini (I know it’s weird, but it makes it nice and creamy) or frozen spinach, use peanut butter instead of almond butter, add chia or flaxseed—the possibilities are endless. We also use less milk so that it’s super thick and creamy.  You can make it more runny if you prefer that. We sometimes eat this as a meal and other times share it as part of dinner or as a refreshing afternoon snack.

If you want to see Camden and I make it live, check us out on Instagram.

For more information on introducing food to little ones from birth to 24 months, check out these two helpful resources on when, how, and what to feed your child. Airplane Choo Choo and Mealtime with Your Little One

I hope you enjoy this as much as we do! 

Yield: 1 meal size or 2 snack size smoothies

Author: Ashley Smith, RD

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Mommy and Me Smoothie

Super thick, creamy, and refreshing--an easy way to get a nutritious meal or snack for both you and your little one!

Prep time: 5 HourTotal time: 5 Hour

Ingredients

• 1.5 cups frozen fruit (I use half mixed berries, half mango)
• 1 Tbsp almond butter
• 1 cup milk (I use whole milk)
• 2 Tbsp plain full fat Greek yogurt 
• 1 scoop of protein powder (plain or vanilla)

Instructions

1. Add all the ingredients to your blender and mix until fully combined and creamy. Add more milk if you prefer the texture to be thinner. 

Notes:

If you're giving this to your little one, be aware of your child's ability to chew/swallow little seeds. If this is a concern, try frozen fruits without a lot of large/hard seeds--strawberries, mango, pineapple, peaches, banana, etc.

If you prefer sweeter smoothies, try adding a date or maple syrup.

If you want to add some veggies, a handful of frozen raw spinach or kale mixes in easily or even steamed, frozen vegetables such as sweet potato or squash!

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 ;