Being a Registered Dietitian, Crossfitter and working in the food industry, I hear A LOT about protein. Whether you’re working towards building muscle, losing weight or just aiming to live a healthier lifestyle – protein seems to always be the way there. Below are 5 common misconceptions about protein, and what the science really says!
Quick Reference on Protein Metabolism to set the stage…
Think of protein like a house. You eat the house, then when it hits your stomach, it begins to get denatured by acid into smaller units.
Now your house is busted up into separate chunks such as the garage or kitchen, these are called polypeptides.
Then, moving into the small intestine, the polypeptides are broken into tri- and dipeptides. Your garage and kitchen now exist only as brick walls and tile floors.
Finally, enzymes further break down the walls and floors into individual bricks and tiles – these are what we call amino acids.
Once broken all the way down into amino acids they are able to “fit” through the intestinal cell walls and into the blood stream. Individual bricks and tiles are much easier to transport than the whole house! So getting into the blood stream allows them a means of transportation to the liver, which is where the fate of those amino acids is determined!
Protein Needs: Normal needs are .8g of protein per kilogram of body weight. So, to get to kilograms, take your weight in pounds, divide by 2.2. Then multiply that number by the .8g of protein. Athletes, those who are sick or have other conditions may need more or less than this, but in general .8-1.2g/kg body weight does the trick.
Myth #1: Protein’s Only Role is to Maintain & Build Muscle – FALSE
Your body is built to be as efficient as possible, meaning, if you ingest more protein than your body really needs, your body WILL find other uses for those bricks and tiles (amino acids). Protein is not just used for muscle! In fact, only about 40% of the body’s protein exists in muscle tissue. And that tissue will release amino acids as needed if you don’t have enough energy (aka glucose) in your blood… So if you think eating mostly protein, and avoiding other foods will help build muscle and cut fat, you will most likely not succeed. Your body will essentially steal amino acids from your muscle for energy. Other uses of protein include regulation of gene expression, building antibodies, hormones and enzymes, transporting substances, maintaining fluid/electrolyte balance and more! Protein is in constant turnover and usage – everyday about 1/4 of your body’s available amino acids are diverted to other uses. You essentially are not the same person you were a year ago due to the complete turnover and replacement of cells.
Myth #2: Soy Protein, Whey Protein, it’s all the Same – FALSE
Different sources of protein have different profiles of amino acids, some more “complete” than others. We call complete proteins ones that contain all 9 essential “bricks and tiles”. These are most ideal for building your house back up, because you have all the right materials. Without eating all of these at once, the body will need to find proteins already in your body to fill in the gaps. Your body can’t start building the bricks walls if you only have the tiles for the floor. Proteins from animals like milk, meat and eggs are the best source of quality protein. Whey protein is also seen as superior source because it comes from milk protein (casein and whey.) However, proteins from plants like pea and soy come along with fiber and variety of other nutrients – so it’s all about balancing a variety of protein sources and eating proteins that “compliment” each other like rice and beans. When eaten together they make a complete protein, but alone they do not.
Myth #3: Protein Can’t Make you Fat, Carbs do That – FALSE
When amino acids are over supplied, the body cannot store them up, so it has basically 3 options: use them for immediate energy needs (a workout), convert to glucose for glycogen storage, or to make fat for energy storage. An oversupply of amino acids causes them to strip of their amine groups which are sent to the kidneys for you to pee out (potential for harm to kidneys if overworked) and then use what’s left to mimic a carbohydrate or fatty acids, hence the ability to contribute to excess energy storage (weight gain.) The three nutrients that yield energy are carbohydrate, protein and fat, that is why they are called macro-nutrients. They work together to always supply the body with energy as its first priority. Micro-nutrients like vitamins and minerals don’t provide energy/calories.
Myth #4: Protein is only Effective after Workouts – NOT EXACTLY
Depends on what effective means to you – if the goal is to make your muscles grow bigger, then timing of protein ingestion plays a role. Within about 1 hour before or after workouts is key. Resistance exercise + protein is needed to build. BUT, it doesn’t mean that protein at other times of the day is wasted. It will still work to maintain muscle you already have and support the processes I stated in #1. Research shows 20-30g of whey or complete protein in a sitting can contribute to muscle building. More may result in an over supply where your amino acids will essentially be wasted and excreted, or used to store fat. To avoid wasting protein, focus on eating complete and high quality proteins in the proper amounts, accompanied by enough carbohydrate/fat as well. The carbohydrate and fat satisfy your energy needs so protein can focus on the muscle part. If you eat strict protein, you can’t expect it to do everything for you, help a protein out yo.
Myth #5: Protein Supplements are King, Work Better than Food – FALSE
Eating complete protein from food is just as effective as protein supplements. Supplements also have higher risks associated with them and are much more expensive than food. I use whey protein to make shakes occasionally to replace a dinner meal, mostly because I just enjoy shakes sometimes and that’s okay. But in no way do I rely on protein supplements as my primary or preferred source of protein. I do A LOT of chicken, tuna and meatless soy/tofu foods. Supplements DO NOT improve athletic performance beyond gains from an adequate diet. Evidence does not support protein supplements for weight loss, as highly concentrated protein can contribute to weight gain, as mentioned above AND does NOT contribute to feeling full because it’s literally just isolated protein as powder (no fiber, no fat, no other components) potentially making you hungrier and want to eat more later.
Side Note: What about BCAA’s or specific amino acids? – MOSTLY CRAP
The body is designed to handle whole proteins best and digest them in a slow manageable way. Excess of one or a group of specific amino acids can cause imbalance or get in the way of other body processes. Below is an excerpt from the 14th Sport Nutrition conference summary. The theme was ‘Nutritional strategies to prepare for the Olympics’ written by a cross functional group of experts. Note they are showing benefits of leucine, BUT recommend this via the intake of FOOD and SNACKS, NOT pumping leucine or BCAAs alone..
What to Tell our Athletes about Consuming Amino Acids
As we’ve discussed, getting leucine into muscles after resistance exercise increases the effectiveness of strength training. Therefore, the key is to deliver enough leucine to the muscle in the day after a heavy gym session. In order to do this, the athlete should:
- Immediately after resistance exercise consume a rapidly absorbable protein source rich in the amino acid leucine.
Examples of this type of food are dairy products (specifically the whey component) and egg whites. Getting it in quickly takes advantage of the higher LAT1 at the membrane following resistance exercise.
- In the 24 hours after resistance exercise, eat snacks containing 20 grams of leucine rich amino acids first thing in the morning and then every 3-4 hours after that. 20g of amino acids maximally activate protein synthesis and get in better in the 24 hours after resistance exercise because of the higher LAT1 RNA levels.
- Consume 30-40g of leucine rich protein right before bed. This protein doesn’t need to be as rapidly absorbed (casein is fine). Eating right before bed improves protein synthesis while we sleep and keeps us in positive protein balance overnight
(Res et al., 2012).
To summarize, the US population is not lacking protein. I would encourage those interested in optimizing their diet or performance with protein to consider a personalized protein strategy vs. just trying to pump more!