What are Macronutrients?

by | Nov 20, 2019 | Nutrition

Highlights

  • There are three macronutrients: carbohydrates, proteins, and fats
  • Carbohydrates include categories: simple, complex and fiber
  • Vegetables are carbohydrates too
  • Protein includes essential (we need in diet) and non-essential (the body can make) amino acids
  • Protein and fats are the building blocks of most cells
  • The type of fats you eat matter – your brain is ~ 60% fats

The Nutrients in Food

Food without a nutrient is therefore not food. Food is the basic necessity of life and if we go back in time then Hippocrates would tell you that food is also medicine for the body. However, first, we must understand what food is and how it nourishes and impacts us. So, we start with the basics. Nutrients are divided into two categories: macronutrients and micronutrients. Our body needs macronutrients to produce energy, in the form of calories, which can extract from carbohydrates, proteins, and fats. Micronutrients are needed in smaller amounts such as your vitamins and minerals.

Let’s dive in to take a look at the 3 main macronutrients:

  1. Carbohydrates – provide 4 kcal per gram
  2. Protein – provide 4 kcal per gram
  3. Fats – provide 9 kcal per gram

**Although alcohol is not a nutrient or needed by the body it does provide 7 kcal per gram.

Carbohydrates

Carbohydrate sources of food

Carbohydrates are one out of the three macronutrients and one that requires the least amount of work to break down. Carbohydrates are made up of carbon, hydrogen, and oxygen. When one consumes carbohydrates, they are broken down into smaller molecules aka glucose in the blood. Once they are broken down, they are carried to different organs of the body for utilization.

When a large amount of glucose is present in the blood, the excess amount gets transported to the liver and muscles to be stored as glycogen. When the liver and muscles reach full capacity then the rest of the excess glucose is sent straight to your fat tissues to be stored as fat in the form of triglycerides (TAG).Muscles can store ~500g and the liver can store ~100g of glycogen. The liver stores of glycogen are only released when the circulating levels of glucose are low in the blood.

Your muscles are a bit selfish and they like to hold onto glycogen for themselves. One because they do not have the enzyme needed to convert glycogen to glucose to release in the blood; second, in the case of emergency – like when you have to run away from a tiger, they are prepared with the fuel you to full power.

Forms of dietary carbohydrates

  1. Simple carbohydrates
  2. Complex carbohydrates
    1. Fibers
    2. Starch

Functions

  • Supply energy to the body. Your red blood cells rely solely on glucose as fuel, and a very small amount of glucose is needed by the brain as well, but the brain can also utilize ketones derived from fat breakdown.
  • Carbohydrates are a source of energy source during high-intensity training and some aerobic exercises.
  • Carbohydrates are important for the oxidation of fat and can also partly convert to protein.

Simple Carbohydrates

Simple carbohydrates are just that-simple. They include glucose, lactose, sucrose, maltose, and fructose. Sugar is a component of simple carbohydrates. They can be found naturally in grains, fruits, milk, milk products, honey, and some veggies. Some simple carbohydrates found in processed/refined foods include: sugar, soda, corn syrup, high fructose corn syrup, and fruit juice concentrates and these are the most void of nutrition.

They are short-chain carbohydrates and always have a sweet taste. Basically, simple carbohydrates are broken down into glucose and easily and quickly used for energy. The reason for this is because simple carbohydrates contain little fiber. Overeating simple carbohydrates results in higher insulin/glucose spike, creating all sorts of havoc on the body.

Now there are techniques, times, and strategies that can be used applied to include them into your lifestyle, especially if you are training and have specific fitness goals, but for the sake of sticking to this topic, we will not dive into that.

Complex Carbohydrate

Complex carbohydrates have long chains of glucose molecules joined together. They include fiber and starch as components. Many times, starch is a word used instead of complex carbohydrates. I know it gets confusing, but hopefully, this simplifies it. Starches consist of long chains of glucose molecules joined together by a bond.

Starchy foods include root vegetables such as peas, potatoes, beans, yams, chickpeas, and corn. Grains such as rice, oats, barley, millet, and wheat. Starch is the most common type of carb used today like cereal grain and they are highly refined. Highly refined starches are stripped of almost all nutrients and fiber, so basically, serve as empty calories.

Fiber

Fiber is generally not digested by the body; however, it has functions and purposes for our health. Fiber does fall under complex carbohydrates and is obtained from plant foods only. Fiber comes in the form of soluble and insoluble fiber.

Soluble fiber dissolves in water, keeps you fuller longer, slow digestion, and plays a role in lowering glucose and cholesterol. Found in oatmeal, beans, lentils, nuts, apples, and berries to name some.

Insoluble fiber helps move food through the digestive tract faster, therefore, keeps you regular, and feeds the healthy bacteria in the gut. Found in whole grains, brown rice, legumes, carrots, tomatoes, cucumbers to name a few.

As with anything balance is key and since we are all different an average recommendation does not really work for carbohydrates. It’s why we say nutrition is personalized.

Protein

Variety of protein sources

Protein is an essential macronutrient. It is made up of smaller units called amino acids. After fat, almost everything in the body is made up of protein. In e.g. hormones, enzymes, and bodily chemicals. Proteins consist of carbon, hydrogen, oxygen, and nitrogen and sometimes sulfur and phosphorus.

Protein is also the main building block for your bones, DNA, muscles, cartilage, skin, nerves, and blood. They also regulate cellular and physiological activities. So, protein is essential to health, healing, and repair. Proteins are readily obtained from meat products, dairy products, seafood, some vegetables, whole grains, beans, lentils, seeds, and nuts, etc.

Essential

There is a total of 20 amino acids that exist in nature. For humans, 9 amino acids are essential which means we must include it in our diet and they cannot be made by the body. They are Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Leucine, and Lysine.

Nonessential

11 are non-essential means they can be made in the body and they are Alanine, Arginine, Asparagine, Aspartate, Cysteine, Glutamine, Glycine, Glutamic Acid, Proline, Serine, and Tyrosine.

Functions

  • Important for proper growth and maintenance as they provide structure for all cells and tissues such as collagen, the most abundant protein, for skin, tendons, connective tissue. Keratin for skin, hair, and nails. Elastin for providing flexibility in the framework of your organs.
  • Responsible for many chemical reactions such as the production of enzymes, digestion, repairs damaged tissues in the body, blood clotting, muscle contraction, energy production.
  • Serves as a chemical messenger for glucose uptake, stimulation of tissue growth, the stress hormone, and reabsorption of water. They include peptides, steroids, insulin, glucagon, human growth hormone, antidiuretic hormone, and adrenocorticotropic hormones.
  • Responsible for the transport of substances across the cell membrane.
  • Maintains fluid balance and boosts your immune system with antibodies and immunoglobulins to fight intruders.
  • Hemoglobin, that makes up your red blood cells, are involved in regulating acid-base (pH) balance in the body.
  • Assists in transporting nutrients such as vitamins, minerals, blood sugar, oxygen, and cholesterol.

Protein is very important for a healthy body. Protein, however, consumes a large amount of energy for digestion therefore also burns more calories. In the case where there is not enough fat or carbohydrate in the diet then the body will break down skeletal muscle protein in order to compensate. A minimum protein intake recommendation for healthy people is 0.8g/kg, however, your lifestyle and health state determine the need for protein. Daily calorie recommendation for protein.

Fats/Lipids

Healthy nutritious fats
Healthy vegan fat food sources, omega3, omega6 ingredients – almond, pecan, hazelnuts, walnuts, olive oil, chia seeds, avocado, coconut, dark green background copy space

Lipids, supply the most calories for the body and brain. Similar to carbohydrates fats are also made up of carbon, hydrogen, and oxygen. In comparison, carbohydrates fats have a higher hydrogen ratio and thus provides a higher calorie (9kcal) intake per gram. There are four important types of lipids: fats, waxes, phospholipids, and steroids.

Fats are larger molecules composed of 3 fatty acids and 1 glycerol backbone. Most dietary fats are in the form of triglycerides. Excess fat is reserved in adipose tissue and is metabolized once the body has exhausted its carbohydrate reserve. Oils are a type of fat. We are familiar with the different types of fats that we consume daily in various forms of fats known as saturated, trans fats, unsaturated, polyunsaturated, and monounsaturated. Fats are naturally present in avocados, meats, fatty fish, nuts, cheese, eggs, and chia seeds.

Fats are larger molecules composed of 3 fatty acids and 1 glycerol backbone. Most dietary fats are in the form of triglycerides. Excess fat is reserved in adipose tissue and is metabolized once the body has exhausted its carbohydrate reserve. Oils are a type of fat. We are familiar with the different types of fats that we consume daily in various forms of fats known as saturated, trans fats, unsaturated, polyunsaturated, and monounsaturated. It is worth mentioning that Omega 3s and Omega-6s are important fatty acids for our health and have many benefits if consumed in the right amount.

Waxes are similar to fats but are found in plants mostly, that help them protect themselves. Ever see water droplets on leaves and how it does not get absorbed well that wax. It is what gives plants that the shiny coat you often see.

Phospholipids are important. These are the main structural component of all cell membranes. The type of fats you consume will affect the makeup of the membrane.

Steroids are different in structure from the other lipids. The most important and common steroid is cholesterol, which is what testosterone and estrogen, male and female hormones are made up of. It is also important for bile acids, which help digest fats and is needed to make vitamin D.

Fats have had a bad reputation for a very long time and the low-fat diets are behind us now. So, it is time to embrace fats. Fats are essential to our health and the proper functions of our brain and body. The type of fat you eat is important because not all fat is created equal. Good fat promotes good health.

Types of Fats

Saturated fats

Single bonded fats are saturated and mostly solid at room temperature. Popular foods include coconut oil, butter, cacao butter, lard, ghee, whole milk, and palm oil. Pretty much all animal foods naturally contain saturated fats. Saturated fats have different effects on health and it really depends on the individual and their genetics to how they respond to them.

Trans fats (trans fatty acids)

Trans fats are known as the unhealthiest form of fats. These are often present in hydrogenated oils. Typically found in fast food, margarine, vegetable shortening, baked goods, and processed and refined foods.

Sometimes they are also naturally present in meats and milk. It is beneficial to keep consumption very low to none. The reason hydrogenation is one is because it gives oils or margarine saturated fats properties and increases shelf life. FDA has banned trans-fat so most companies have already removed them or are in the process of.

Why trans fatty acids are not good for health

  • ~2% of calories consumed from trans-fat in a day can predispose one to coronary heart development by 23%
  • Increases the number of low-density lipoproteins (LDL-D) in the body
  • Can lead to insulin resistance
  • Cause of inflammation. At the very heart of inflammation are many disease developments e.g. stroke, heart abnormalities, diabetes, etc.

Unsaturated

Unsaturated fats are double bonded and liquid at room temperature. They typically are obtained from plant sources like olive oil, avocado, and nuts. Unsaturated fats, mostly called oils, are of two categories; monounsaturated and polyunsaturated

Monounsaturated fats

They contain one double bond and so are called monounsaturated. Often found in animal and plant foods. Typical sources include olive oil (richest), avocado, almonds, cashews, peanuts, pistachios, and avocado oil. Monounsaturated fats have numerous health benefits and are the main component of the Mediterranean diet. It is an excellent oil for improving lipid profiles, insulin sensitivity, may reduce the risk of cancer, and may reduce inflammation.

Polyunsaturated fats

Multiple doubles bonds make up polyunsaturated fats. These are essential fats for the body. There are three essential fatty acids – polyunsaturated fatty acids (PUFA), linoleic acid ((LA) omega 6s), and alpha-linolenic acid ((ALA) omega 3s), which we must include in our diet.

It is worth mentioning that Omega 3s (EPA + DHA) and Omega-6s are important fatty acids for our health and have many benefits if consumed in the right amount. Sources of food include salmon, herring, sardines, trout, walnuts, tofu, oysters, and seeds.

Functions

  • Fats are very important for health.
  • Your brain is 60% fat and very unique composition – more on it later
  • Fat makes up cells membrane and controls the movement of substances in and out.
  • They are carriers for fat-soluble vitamins
  • Insulates and protects your organs

About Me

Hi, I’m a registered dietitian. It’s my personal mission to offer clear and easy to understand information and actions that will increase your depth of knowledge and make optimizing your health a breeze. Happy reading!

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