Protein: The Muscle-building Macronutrient

Welcome to “Diet Basics”, a series where we take all that tasty dietary information and break it down into what you need to know to make better diet decisions in your everyday eating habits. Diet isn’t about a temporary fix or a set of steps you take in the short term to fix everything just so you can go back to bad habits when you’re “done” with the diet. A good diet is a lifestyle choice that you should be consciously making until it becomes habit. This series will arm you with the information you need to make those healthy decisions, and start replacing your bad eating habits (Kit-Kats are not a food group!) with good eating habits (have some carrots, seriously).

Today we’re going to discuss my favorite macro-nutrient: Protein!

What is Protein?

There are two ways you can look at Protein, from a nutrient point of view and from a chemical point of view.

Chemically, a protein is a large biological molecule that is made up of amino acid chains. Different combinations of the 20 base amino acids can create different proteins, which all have a different structure and function.The proteins we’re talking about here are basically inherently involved in…well…everything your body cells do. Ever. Seriously. From metabolic reactions to DNA synthesis, proteins are involved in basically everything your body does from start to finish. This article isn’t going to be comprehensive enough to go into all the details, but I wanted to mention this because, hey, I’m a nerd and like science!

Now, we’re concerned with the nutrient version of protein, which is one of the macro-nutrients that is called out on food labels and generally shown as “grams per serving”. Proteins are an essential dietary element for humans, and form one of the basic building blocks of body tissue – most notable for us is muscle. Dietary protein is broken down to it’s constituent parts (i.e. amino acid chains) in the stomach during digestion, so the elements can be shunted to wherever they need to be in the body.

What does Protein do?

Dietary protein provides amino acids to the body, which are then used for a variety of functions from DNA synthesis (boring) to building muscle (the good stuff). As I mentioned above, there are 20 amino acids which are available in different amounts via dietary protein. These are split into Essential, Non-Essential, and Conditional categories.

Essential: Cannot be produced by the human body and must be obtained from food. They are: leucine, isoleucine, valine, lysine, threonine, tryptophan, methionine, phenylalanine, and histidine.

Non-Essential: Can be created (“synthesized”) in the human body using essential amino acids as building blocks; they may also be obtained from food. They include: alanine, asparagine, aspartic acid, and glutamic acid.

Conditional: These are generally not essential to human health, except in specific situations (high stress, illness, some medical conditions). These are: arginine, cysteine, glutamine, glycine, proline, serine, and tyrosine

Protein is used for:

  • Energy. Protein has 4 calories per gram of “food energy”
  • Body growth and maintenance. It is the second most present molecule in the body after water, and can be found in every cell.
  • Needed to create: blood cells, enzymes, co-enzymes, hormones, and nucleic acids.
  • Used to build and repair muscle, which is necessary when performing and recovering from exercise.

Where can I get Protein?

Dietary protein is most readily available from animal sources (meat, milk, eggs, fish), but can also be found in non-animal sources (whole wheat, legumes, soy, fruit, nuts, seeds). Humans are naturally omnivorous, so we tend to eat our proteins from both animal and non-animal sources interchangeably.

Vegetarians and vegans need to watch their protein intake since they eschew the animal sources. This can mean a more formalized diet of non-animal sources to ensure they meet their dietary needs, but realistically you should be keeping a more “formal” eye on your eating habits anyway to prevent diet-related problems (obesity and diabetes, for instance).

You can also obtain dietary protein from special protein powders (vegan and carnivorous versions) that you drink once or twice a day to boost your intake. These can be especially useful if you don’t eat animal sources and need to make up a deficit. They are also good for people who have a hard time eating enough whole sources, regardless of animal or not; some people just can’t eat that much! Exercise caution, however, with these shakes. They tend to be high in carbohydrates and sometimes fats as well, so their caloric load is much higher than just the protein contents. Drinking your calories is always a dangerous proposition if you don’t monitor your intake, and a lot of these shakes will not keep you as full/satiated as a serving of chicken or steak.

How much Protein do you need per day?

This is a subject of much debate amongst fitness and nutrition guru’s and laymen the world over. There are a lot of different opinions on how much protein you need in a day. A lot of this confusion arises because people define the word “need” very differently. Lets look at some different ideas:

US and Canadian Dietary Guidelines from the Dietary Reference Intake (DRI):

  • To avoid deficiency, women (19-70 yrs) should consume 46 grams (184 calories) per day while men (19-70 yrs) should consume 56 grams (224 calories) per day.
  • Generally, this equates to 0.8 grams of protein per kilogram of body weight per day for a sedentary person. Using the above numbers for men and women, this assumes that the average woman weighs in at 126.5 lbs (57.5 kg) and the average man weighs in at 154 lbs (70 kg).
  • This ignores energy requirements of the caloric intake
  • Here’s a little Wikipedia on these guys

Center for Disease Control (CDC) (U.S.)

  • They follow the same basic idea as the DRI above, including giving figures for younger males and females right on their site.
  • In addition, they give the very broad suggestion that protein should make up between 10% and 35% of your total caloric intake per day. That is a huge window and isn’t really helpful.

In contrast, below I’ve detailed how I eat (though I’m not always exact on my figures unless I’m in a specific fat cutting phase). Keep in mind that my exercise, body weight, lean mass, and activity levels all play into these calculations. I’ll give you the math, but you need to get your calculator an scale ready to find your own numbers.

First, lets find out our Lean Mass:

      • Body Weight: 167 lbs (75.91 kg)
        • 1 lb = 2.2 kg
        • 167 / 2.2 = 75.91
      • Body Fat: 14.5%
        • Measured by skin-fold calipers as well as a hand-held, electric body composition tester
      • Lean Mass: 142.79 lbs (64.90 kg)
        • Lean Mass = Body Weight * (1 – Body Fat %)
        • 142.79 = 167 x (1 – 0.145)

I keep it (relatively) simple and aim to eat 0.8 grams of protein per day for each pound of Lean Mass. So…

  • Lean mass: 142.79 lbs
  • Protein Intake: (142.79 lbs) x (0.8 grams / pound) = 114.23 grams / day
  • Caloric Load: (114.23 grams) x (4 calories / gram) = 456.92 calories / day from protein

This might seem like a lot, but keep in mind that I am active and my workouts include a lot of free-weights and big body movements like pull-ups. My muscles get taxed heavily, and I can certainly use the calories! In general, I would recommend that you cut down the protein intake to 0.7 grams per pound Lean Mass on days where you don’t exercise, to help keep your calories in check.

So that’s it! Nice and simple. right? Next time we’ll talk about dietary Fat, and why you should stop being afraid of it.