Protein 101

We are excited to sit down with the new Registered Dietitian, Aaron Smith to learn more about him and how we can maximize protein in our diet. 

Tell us about yourself.
Hello! My name is Aaron Smith. I am the new registered dietitian at the Mettler Center. I handle all nutrition counseling sessions and anything else that pertains to nutrition. In the future, we hope to reach out to other similar businesses and develop partnerships with them.

I recently graduated with my master’s in nutrition from Southern Illinois University – Carbondale. Subsequently, I passed my exam to become a registered dietitian. Additionally, I am a personal trainer certified through the American College of Sports Medicine and I teach a nutrition class at Kaskaskia College. I pride myself in providing truthful, evidence-based information!

What is dietary protein?
Protein consists of amino acids and is linked together by peptide bonds. Amino acids can be thought of as the building blocks and peptide bonds are what link these building blocks together.

Why is protein important?
Frankly, you cannot live without eating protein! Dietary protein is a constituent in every cell, helps maintain and build muscle mass, maintains and may improve immune function, maintains bone density, may help promote weight loss and maintain a healthy weight.

How much protein should I consume?
That’s a tough question to answer. There a lot of factors that need to be considered. To prevent a protein deficiency, you need 0.8 grams of protein per kilogram of bodyweight (divide your weight in pounds by 2.2 to figure out your weight in kilograms). For a sedentary individual, I recommend 1.2 grams of protein per kg of bodyweight. Individuals involved in endurance exercise 1.4–1.6 kg/bodyweight and strength training 1.6–2.0.

As a Registered Dietitian, what advice do you typically give to individuals who want to incorporate more protein in their diet throughout the day?
I recommend clients to have a protein source at every meal. It is best to evenly distribute your protein feedings throughout the day. For example, breakfast, lunch, dinner, and perhaps one or two snacks.

Many people utilize protein shakes and bars. Any advice when it comes to this?
There is nothing wrong with protein supplements/bars. In fact, they can be convenient and offer some benefits! Evidence has shown that protein supplements may help individuals lose weight and maintain weight loss. However, individuals that go this route need to be cognizant of added sugars that sometimes are added to supplements, especially the bars. Also, the supplement industry is largely unregulated. Sometimes supplement companies add cheap fillers to their powders to save money. Look for independent seals from labs that verify that product ingredients, such as the NSF seal.

What about the person who is a vegetarian, what can they do to get enough protein each day?
Not all protein sources are created equally. Animal sources of protein are better utilized by the body. But don’t worry vegetarians—you can complement your protein sources to make them better utilized by the body! In general, vegetarian sources have a rate limiting amino acid, which makes them inferior to animal sources. However, you can combine two different plant protein sources that complement the missing amino acids, such as rice and beans. As long as these protein sources are consumed within several hours of each other, the benefits can be reaped! For the sake of time, I recommend individuals who are interested in this to look up “protein complementation” on Google. Also, soy is an excellent vegetarian protein source.

Are high-protein diets safe?
Absolutely! Innumerable studies have shown that high-protein diets are safe and do not lead to deleterious effects to the kidneys, bone density, etc. Some evidence has tested protein diets as high as 4.0 g of protein per kg of bodyweight and found no negative effects! As long as protein does not displace valuable foods, such as fruits and vegetables, is it perfectly safe!

This was great information! There might be people out there that would really like to learn more on what would work for them. What are their options?
The best thing they can do is schedule a complimentary 30-minute consult with me at Mettler Center and we can talk through what their goals and find solutions that work for them! Or, if they have a question they can submit it through Ask an Expert on our website at