If you’ve read or researched the wide world of nutrition for any length of time, you’ve probably heard the term “macronutrient.” It usually refers to the three main types of “food” in the human diet – proteins, carbs, and fats (full disclosure – a few more items can be lumped in here but these are the biggies). A few examples of each probably come to mind:
- Carbohydrates – rice, pasta, bread, etc
- Fat – Avocado, nuts, olive oil, etc
- Protein – Meat, soy, dairy, etc
Macronutrients are important to understand as they form the basic building blocks of your nutrition. For example, the popular Zone diet recommends eating 40/30/30: 40% of your calories come from carbohydrates, 30% come from fats, and 30% come from proteins.
Without understanding macronutrients at least on a surface level, it’s impossible to select the right foods to eat throughout the day. That’s why we’re diving deep on macronutrients for our first discussion topic during our nutrition challenge, which started on Monday, September 10th!
Regardless of whether you’re following the Zone diet, eating Keto, staying Paleo, or, you know, just trying to eat healthier it’s important to understand the distinction between proteins, carbs, and fats. Read on below to learn a bit more about each and find some additional resources to dive in further.
Carbohydrates – More than just bread and pasta
Carbohydrates often get a bad rap in the CrossFit world because of their association with breads, pastas, and potatoes. As we’ll find out, not all carbohydrates should be demonized.
Broadly speaking, carbohydrates can be broken down into two classifications:
- Simple – smaller molecules that are easily broken down by the body. In science terms, these are referred to as mono- and disaccharides, which means either one sugar molecule or two linked together.
- Complex – are larger molecules that take a bit more time to break down. The science-y term for complex carbohydrates is polysaccharides, meaning they have more than two molecules linked together.
Regardless of the type of carbohydrate you consume, it’s first broken down into a monosaccharide (aka a “simple sugar”) in the body. The main difference is that complex carbohydrates (think oatmeal, fibrous vegetables, whole grains, etc) take a longer time to breakdown. Simple carbohydrates (plain sugar, for example) break down very rapidly.
Once the carbohydrates are broken down to simple sugars, they travel to the liver and then are dispersed throughout the body to be used as fuel or stored for later. A lot of hormones play a role in this process, but insulin is the primary hormone that gets a lot of attention. When the liver releases simple sugars into the blood, insulin is released to shuttle those sugars around the body for storage or fuel.
Type II diabetes then is a condition wherein your body has a difficult time processing the sugar in your blood. Your body produces more and more insulin to clear the sugar, but the cells don’t respond meaning the blood sugar continues to accumulate (termed “insulin resistance”).
Carbohydrates get stored in the body in the form of glycogen, which is essentially a chain of sugars hooked together. Glycogen is stored in the muscle and in the liver and can be mobilized by the body in time of need. One gram of carbohydrate contains four calories of energy for the body (compared with nine per gram of fat and four per gram of protein).
- Carbohydrates come in two main forms – simple and complex. Simple carbohydrates are broken down much faster and spike insulin to a much greater degree.
- As we’ve discussed before, keeping blood insulin levels steady throughout the day is key for health and steady energy. Therefore, any carbohydrates you consume should be of the complex variety (think vegetables, whole grains, beans/legumes, etc).
Fats – Not as evil as you might think
Historically, “fat” has been a naughty word in nutrition circles. The overall recommendations from the American Heart Association and others has been to eat a low-fat diet full of whole grains, complex carbohydrates, and lean proteins. Fat, the common thinking went, would make you…well, fat.
It’s important to distinguish between “good” fats and “bad” ones, defining some of the common terms you’ll hear in nutrition circles like “trans fats.”
In broad strokes, fats can be broken down into a few main categories with each category differentiated by chemical composition. For reference, a “fat” molecule is just a string of carbon and hydrogen molecules linked together (called…wait for it…hydrocarbons). Stick with me for a second – I promise we’ll make all this science-speak applicable.
- Saturated fats – Each carbon has a single bond with two hydrogen atoms.
- Monounsaturated fats – One carbon atom in the chain has a double bond with a hydrogen atom. Thus, it’s not “full” or “saturated” with hydrogen atoms.
- Polyunsaturated fats – Two or more carbon atoms have double bonds.
Sounds complicated – I know. A diagram will probably make this a bit easier:
Most foods you can think of (animal protein, nuts and seeds, etc) contain a ratio of saturated and unsaturated fats. Mono- and polyunsaturated fats are typically touted as “good” fats where as saturated fat gets a bad rap. The truth is that all forms of fat can and should be part of a healthy diet. In fact, much of the research showing that saturated fat consumption raises cholesterol levels in the blood is suspect to further investigation (see The Cholesterol Myths).
The modern diet has a few other “newer” forms of fat you might have heard of – trans fats. These are man-made fats that are added to foods to improve mouth feel and increase shelf life of products. Basically, companies take unsaturated fats, “bubble” hydrogen ions through them, and generate “saturated” fats that have a few weird “kinks.” It’s almost universally agreed upon that these are bad for our health.
Unlike carbohydrates, eating fat does not spike insulin. The fat you eat is broken down by the body and either stored, used for energy, or (in the case of some cholesterol) eliminated as a by-product.
The key to understand is that fat does not make you fat. It’s an integral part of your diet. A diet free from fat is not healthy. When consumed from a variety of sources, fat is extremely healthy and provides a dense source of energy for the body.
- Fat comes in three different varieties – saturated, monounsaturated, and polyunsaturated along with trans fats. The first three can all be part of a healthy diet. “Trans fats” are man-made and should be avoided.
- Fat does not make you fat! It provides a dense form of energy for the body and can be mobilized for fuel. “Fat accumulation,” wherein your body stores more fat than it uses for fuel, is regulated more by the hormonal situation in the body than on how much fat you consume.
Protein – Building blocks of more than muscle
Finally, let’s talk about protein, which gets a lot of attention at least within workout circles. Even athletes that know little about nutrition chase a workout with a protein shake for fear of missing the “post-workout window.”
In order to understand proteins, we have to talk a bit about amino acids. Amino acids are “the building blocks of life.” They’re used to build everything in your body from blood cells to organs and much much more. Amino acids are broken down into three categories:
- Essential – Your body cannot produce these amino acids so you have to get them from your diet.
- Nonessential – Your body can produce these amino acids.
Proteins are a collection of amino acids joined together by chemical bonds. A “complete” protein (meat, eggs, etc) contain all of the essential amino acids. “Incomplete” lacks one or more.
When you consume protein, your body breaks it down into amino acids. Those are then shuttled throughout the body to replace worn cells and produce everything from neurotransmitters to muscle cells.
Since protein is so vital for the body, a typical notion is that more is always better. It’s important to realize that the body has an upper limit for protein storage. It can only use and store so much at a given time. So, consuming 100g of protein at a single sitting isn’t going to do much good – you’ll end up excreting a good bit of it. Instead, your body can use a constant stream of protein throughout the day – picking good quality sources of protein at each meal.
What about that post-workout window? The common thinking is that during a workout, we’re breaking down muscle cells. As a result, we need to consume protein immediately afterwards to start the recovery process. Post-workout protein (especially when consumed with carbohydrates) can help muscle recovery, but it’s important to get it from the right sources. Chocolate milk, for example, is packed with sugar, and as a result, is a sub-optimal choice despite having protein. A better choice would be chicken plus some berries or a good protein powder with an apple – good sources of protein and fibrous carbohydrates.
- Proteins are essentially collections of amino acids. Amino acids form the building blocks for all of our cells.
- Proteins can be either “complete” or “incomplete” based on their amino acid profile.
- Try to consume a good source of protein with each meal to ensure your body is constantly stocked (versus trying to get it all in at once).
Hungry for more (sorry, I couldn’t resist)? Check out the following resources to learn more about macronutrients and how they fit in to any healthy eating plan:
- Proteins and fats on the CrossFit Journal
- Carbohydrates on the CrossFit Journal
- Dr. Michael Ray on Macronutrients on the CrossFit Journal
- Zone Meal Plans on the CrossFit Journal – use this less for the specific Zone guidelines (you can do Zone if you want!) and more for the favorable sources of each macronutrient