The topic of nutrition is one that’s often confusing for people to understand. Especially since there are numerous professionals who all have their own opinions present the latest fad on what’s the best way to eat. However, regardless of the latest fad, or what will help you lose weight the fastest, the one thing we can’t deny is science and how nutrition really works in the body.
In this blog, I answer the common question of “what are macronutrients,” review how they work in the body and discuss which one is the most important.
What Are Macronutrients?
Macronutrients include protein, carbohydrates and fats and are what make up the food we eat that our body requires for fuel. Once ingested, the body breaks down the food into their basic building blocks of amino acids, monosaccharides and fatty acids. These chemical components are then absorbed in the body and delivered to the cells to support a variety of vital functions.
Many different opinions exist on how much of these macronutrients we need for optimal health. I will review the recommended intake for each macronutrient soon; however, it’s important to find the balance that works best for you and your goals.
1) CARBOHYDRATES
Carbohydrates serve a variety of vital functions and are one of the most important macronutrients. Carbohydrates are the body’s preferred source of energy (providing four calories per gram), and the only energy source for red blood cells and the brain, help support digestive health and manage cholesterol levels.
Without speaking too much science jargon about chemical structure (yes, I know snoozer, right?), I w’ll explain the various kinds of carbohydrates, which are categorized into monosaccharides (made of carbon and water) and disaccharides (two monosaccharides).
Monosaccharides:
- Glucose: Glucose, also known as dextrose, is the basic building block of most carbohydrates and is the predominant sugar found in nature.
- Fructose: Fructose, or fruit sugar, is the sweetest and found in fruit in varying amounts.
- Galactose: Is as sweet as glucose and often found bound to glucose to form lactose.
Disaccharides:
- Lactose: Comprised of the link between galactose and glucose and is the predominant sugar in milk.
- Maltose: Comprised of two glucose molecules and better known as malt sugar.
- Sucrose: Comprised of glucose and fructose and more commonly known as table sugar.
Unfortunately, when people talk about carbohydrates, they most often think of candy, baked goods, bread, pasta, and cereal, mostly refined, white or whole-wheat sources of carbohydrates.
These refined carbohydrates are usually full of sugar and chemical preservatives, which harm and break down body tissues and organs. However, these are not the kind of carbohydrates that the body requires for fuel.
What the body needs are healthy carbohydrates that come from pure earth grown sources. These include foods such as oats, sweet potatoes, whole grains such as brown rice, millet, amaranth and quinoa, starchy vegetables and fruit.
These healthy carbohydrates not only provide the body with the fuel it needs to move but also fibre, for healthy digestion, and keeping cholesterol at healthy levels.
Without these foods in the short-term, people begin to feel the negative effects such as low energy, brain fog and crankiness. In the long-term, people increase their risk of constipation, increased cholesterol, heart disease and cancer.
Many people shy away from eating fruit, or other whole-food carbohydrate sources, due to the high sugar content. However, even though there’s sugar in these foods there’s also fibre and a variety of essential micronutrients, like vitamins and minerals, (which I will review in a later blog), that we need for energy, healthy digestion and optimal health.
It’s true, many of the carbohydrates people eat and crave are processed and cause weight gain and other health problems. Unfortunately, thanks to media and fad diets all carbohydrates have been vilified.
Therefore, most people do not eat enough of the right kind of carbohydrates such as whole-food complex carbs that are found in whole-grains and vegetables. As a result, fiber intake is low and digestive problems, like constipation and colon cancer, are more common than ever.
You may be thinking, “How much carbohydrates do I need for optimal health?”
That’s a great question!
According to the dietary reference intake suggestions an active individual may require 6-10 grams of carbohydrates per kilogram of body weight.
A sedentary person, someone who does less than 30 minutes of activity less than three days per week, may only need one and a half grams per pound.
This is often where carbohydrates get their bad name. It’s not the carbs that are bad; it’s overconsumption, and underutilization, that’s causing the problem.
Think of it this way…
Carbohydrates are like gas in the tank of your car. You need to have gas in the tank to drive your car but the amount of gas you need will depend on how much you drive your car. Going on a long drive…you’ll will need a full tank. Not driving at all, or just a short distance…you won’t need much gas.
The same this is true with carbohydrates. If you are an athlete, or someone who trains their body on a regular basis, you will need more energy from carbohydrates that someone who is sick and lying in a bed. In the that case, the person will need minimal carbohydrates if any at all.
Regardless of activity levels, it’s recommended that carbohydrates, specifically whole-grains and food high in fibre, make up 45%-65% of your total diet to adequately fuel your body (depending on the resource, and your personal goals, these numbers will vary). Studies show that of this carbohydrate intake, 25 to 35 grams of fibre per day is optimal for most adults.
To determine which carbohydrates are the best to consume many professionals refer the the glycemic index (GI). This system assigns a value to foods based on how slowly or how quickly those foods cause increases in blood glucose levels. Also known as “blood sugar,” blood glucose levels above normal are toxic and can cause blindness, kidney failure, or increase cardiovascular risk.
Foods low on the GI scale tend to release glucose slowly and steadily. Foods high on the scale release glucose rapidly. Low GI foods tend to contain higher levels of fibre and support weight loss, while foods high on the GI scale are usually higher in sugar and help with energy during or recovery after exercise, or to offset hypo-glycaemia (low blood sugar levels).
Although carbohydrates are the most important macronutrient for your body to function effectively, too much sugar in the body can be very damaging and lead to diabetes, cancer and other chronic diseases. Therefore, it’s important to speak to a registered dietician, or certified nutrition professional, about the best intake for your personal needs.
If you’d like to learn more about what carbohydrates, and other foods to eat fuel your body for exercise please read the blog, “How To Fuel Intense Workouts With A Plant-Based Diet.”
2) PROTEIN
The body is made of mostly protein. It is the main structural component of muscle, brain, nervous system, blood, skin and hair. This macronutrient serves as a transport mechanism for vitamins, minerals, fat and oxygen and is essential for acid-base balance, the building and repair and tissues, hormone and enzyme production and help to sustain the energy provided by carbohydrates.
Protein is not a preferred fuel source for the body. However, it will breakdown proteins for energy (as protein will yield four calories per gram) if the body is starving and lacking carbohydrates and fat.
When people find out I eat a 100% plant-based diet the first question they ask is, “where do you get your protein?” I used to be offended by this question because it seemed so silly. I quickly realized that it was because people know very little about where protein comes from. Now, I love this question as it gives me the chance to educate them on what foods contain protein.
Think back to high school biology. Do you remember learning about plants, how the cells function and what they are made of? It’s a very simple concept: anything with a living cell contains protein, or amino acids, which are the building blocks of protein. So, all living food contains protein.
What about the starving kids in the world; they are protein deficient. Yes, they are because they are starving! Anyone who lacks sufficient calories to sustain basic metabolic functions will be protein deficient but if you eat a well-balanced diet that includes fresh, living fruits and vegetables it is unlikely you will be protein deficient.
If you have ever tried to eat a vegan diet and found your energy levels plummet this is usually because you’ve not eaten enough calories, not because you are low in protein.
Think about some of the largest mammals like gorillas, elephants, and hippopotamus. They are herbivores and eat nothing but plant foods yet they are strong, powerful and seem to have more than enough protein in their diets.
The body can produce most of the protein it needs, which are called non-non-essential amino acids. However, there are eight to 10 essential amino acids that cannot be made by the body; therefore, need to be consumed in the diet.
Protein quality is determined by assessing the amino-acid composition, digestibility and bioavailability, which is how well the amino acid can be used by the body.
People often believe that they must consume animal protein to get enough, as animal protein is a complete protein. Whereas plant-protein is often though of as not having enough protein because many plant-based protein sources are incomplete proteins.
However, there are many plant-based complete protein sources , such as soy, quinoa, buckwheat and sprouts, that are not only easier for the body to digest but also don’t contain the saturated fat (which we will talk about later in the blog) that come from animal products.
A well-rounded, whole-food, plant-based diet will also allow for complete proteins to be made by eating a variety of incomplete proteins. The old belief used to be that a person needed to eat different incomplete proteins, such as grains with nuts, or legumes with dairy, in order to get a complete protein.
But this is not true.
As long as a variety of these foods are eaten in the diet, the body knows how to put them together to make the compete proteins it requires.
When it comes to bioavailability, the body’s ability to use protein, plant-based protein has been found to be more bioavailable than animal protein.
For example, dark leafy greens are rich in easy-to-digest protein and about 75% of the amino acids, or protein, found in dark leafy greens are usable by the body. In comparison to meat, where only 25% of the amino acids are usable and the rest is eliminated as waste or sits in the digestive tract to rot.
According to the dietary reference intake suggestions the average person requires only about 0.8 grams and strength athletes needing about 1.7 grams of protein per kilogram of body weight. As a percentage breakdown, it’s recommended that protein make up about 25% of the total diet (depending on the resource, and your personal goals, these numbers may vary).
I’m saddened by by the fad diets that promote high-protein and low-carbohydrate diets. Athletes, or active people are especially at risk because if glycogen stores are depleted, the body will breakdown muscle protein for fuel resulting in decreased athletic performance and muscular strength and endurance. Many athletes have suffered extreme fatigue, and some even heart attacks as the body desperately searches for fuel.
If you’d like more information on the protein available in plant-based foods please read the blog, “21 Best Sources Of Plant-Based Protein.”
3) FAT
Fat provides the body with the most energy of all three macronutrients at nine calories per gram. Therefore, it’s best to consume fat in moderation is weight loss is a goal. However, fat is an important macronutrient that must be part of a healthy, well-balanced diet.
Critical functions in the body such as organ insulation, cell structure, nerve transmission, vitamin absorption and hormone production depend on fat.
Saturated fatty acids (saturated fats) come from animals and coconuts and are solid at room temperature.
The most well known saturated fats come from animal products; however, the biggest problem with animal fat is that it’s also been shown to increased LDL (the bad) cholesterol and increase risk of atherosclerosis (clogging of the arteries) and heart disease.
To eat animal sources of saturated fat a person must cook the meat to kill the harmful bacteria. However, once these fats are heated they become rancid and harmful to the body.
The healthiest kind of saturated fat comes from coconuts as raw coconut meat, coconut butter or coconut oil. The difference between the saturated fat in animal products and that of a coconut is the chemical structure.
According to Dr. Mercola, coconut oil is made up of about two-thirds medium-chain fatty acids as opposed to the long-chain fatty acids found in other saturated fat.
Coconut oil is found to be healthy because 50% of the fat content is lauric acid. The body breaks down lauric acid into monolaurin and then uses this compound to destroy viruses such as HIV, herpes, measles and influenza.
Other benefits of coconut oil include immune support, weight loss, heart health, healthy metabolism, energy source, beautiful skin and supports healthy function of the nervous and endocrine systems.
If you must cook with oil, coconut oil is, in my opinion, the best oil to choose. It’s minimally refined and has a high heat tolerance.
Hydrogenated (trans) fat is often used in processed foods, such as commercial baked goods, cookies, doughnuts, muffins, cakes and pizza dough; snack foods such as crackers, microwave popcorn and chips; vegetable shortening; fried foods like French fries, fried chicken, chicken nuggets, and breaded fish; and candy bars as a preservative to provide a longer shelf life.
The problem is that trans-fatty acid is toxic to the body and has also been shown to raise LDL cholesterol and increase your risk of disease.
For optimal health, it is best to refrain from eating all foods that contain trans fats.
Unsaturated fats are broken into two categories: monounsaturated and polyunsaturated. These fats are healthy fats and support a healthy heart.
- Monounsaturated fats have been shown to increase HDL (the good) cholesterol and can be found in foods like olives and olive oil, peanuts and peanut oil, sesame oil, avocados, cacao beans, almonds, pecans, cashews, macadamia nuts and hazelnuts.
- Polyunsaturated fats have been shown by the American Heart Association to be beneficial for the heart when eaten in moderation and used to replace saturated fat in the diet. These fats are most dominant in walnuts, sunflower, sesame, pumpkin seeds, flaxseed, hemp and tofu.
- Essential fatty acids (omega’s) are a type of polyunsaturated fat that need to be consumed in the diet because the body is not able to make them.
- Omega fatty acids, are essential fatty acids that include omega 3, 6, 7, and 9. They must be consumed by the diet and provide numerous health benefits to the body.
To learn more about omega fatty acids, where to find them and the numerous health benefits, read my blog, “Why A Plant-Based Omega Blend Is Better For You.”
Over the years fat has been vilified by weight loss industries; therefore, food companies have done their best to provide food with reduced fat. However, food companies that boast fat-free products often just replace fat with refined sugar, causing more harm than good, and often more weight gain.
According to the dietary reference intake suggestions an individual may require about 0.2-0.4 grams of fat per pound of body weight and total intake should be less than 30% of the total diet (depending on the resource, and your personal goals, these numbers will vary).
Despite the great need for fat to achieve optimal body function and health people continue to strive towards achieving low-levels of body fat in the name of vanity. Yes, too much fat isn’t good either, and will cause a variety of health problems, the diet still must contain a certain amount of healthy fat to provide the body with energy, protection and optimal health.
In conclusion…
It’s clear to see that based on science all three macronutrients are important to be included in a well-balanced diet. Carbohydrates and fat are the body’s preferred source of energy whereas protein is used mostly in building, recovery and repair of tissues.
To achieve optimal health, it’s important to eat a diet that is well-well-balanced in all three macronutrients. Please connect with a health professional to discuss what the best balance looks like for you and your goals.
References:
Until next time….happy eating!
Namaste!
Rachel Joy Olsen, BSc., MBA
Read my, “From Frog Killer To Compassionate Vegan” story.