I get asked all the time about macronutrients, micronutrients, and calories and I am going to break them up and explain their role to our nutrition in more detail.
Let’s dive right in:
Macronutrients (macro = large): Nutrients our bodies need in large quantity (proteins, carbs, and fats).
Micronutrients (micro = small): Nutrients our bodies need in small quantity (vitamins and minerals).
Calories: Calories is the fuel our bodies take in to keep us alive and functioning. A calorie (cal) is the amount of energy it takes to raise 1g of water from 0 to 1°C. This is often used in chemistry and physics. When referring to nutrition, the measurement used is in kilocalories or kCal (It may also be represented as Calorie or Cal, compared to calorie or cal. The capital ‘C’ represents the greater measurement, but one can see how this can get confusing) — the amount of energy it takes to raise the 1kg of water from 0 to 1°C. Total caloric value is calculated by adding up the calories provided by the energy-containing macronutrients: protein, carbohydrate, and fat. Each are measured in grams.
- 1g of protein = 4 kCal
- 1g of carb = 4 kCal
- 1g of fat = 9 kCal
Protein’s general conception is that it’s what our body uses to build and repair our muscles, but more than that, proteins catalyse reactions in our bodies, transport molecules such as oxygen, keep us healthy as part of the immune system and transmit messages from cell to cell. The smallest unit of protein is the amino acid. When amino acids are joined together, they form peptides or peptide chains which make up the primary protein structure.
Carbohydrate’s general role is to provide us with energy, it’s also our brain’s main source of fuel. If taking on the keto diet (less than 50g or carbs/day and high fats), we tend to feel lethargic and brain dead until we’re put into ketosis for this reason.
In the body, carbs are broken down during digestion into saccharides (sugar), they can be divided into 3 groups based on their level of complexity:
- Monosaccharides (mono = one): The simplest form of a carbohydrate, they only contain one sugar group, or chain link. Glucose is a monosaccharide, it is the product of carbohydrate metabolism and our major source of energy. Fructose is very sweet; possesses a ketone rather than an aldehyde, which distinguishes it from glucose. Galactose is less soluble and sweet than glucose.
- Oligosaccharides (oligo = little or few): Short chains of monosaccharides linked together, disaccharides = 2 sugars (Maltose = glucose + glucose, Sucrose = glucose + fructose, Lactose = glucose + galactose), trisaccharides = 3 sugars, up to 10 chains.
- Polysaccharides (poly = many): Long complex chains of linked monosaccharides (glycogen, fiber, or starches). >10 chains.
We can break it down even simpler into 2 groups, again, based on the complexity of the chain: simple carbs (monosaccharides and oligosaccharides) and complex carbs (polysaccharides). The more complex the carb, the more time it’ll take to metabolize. Glycogen is a stored form of glucose, when the body doesn’t need anymore glucose for energy, it takes the polysaccharides and stores it in the liver and muscles as glycogen and provides the body with a readily available source of energy if blood glucose levels decrease. Fibrous carbs don’t get digested or absorbed, but it gets broken down and passes through the GI tract, so they are essential for keeping the digestive process running clean and healthy (think cleanse). Fiber is also an excellent source of micronutrients. That leaves us with starches. There are two types of starch:
- Unrefined: Brown rice, wholemeal flour
- Refined: White rice, white flour
Unrefined carbs are more complex than refined carbs, this is where the debate whether brown rice is good and white rice is bad. Refining brown rice into white rice strips it of its bran and germ as well as its fiber, vitamins and minerals. It’s then processed further to improve taste, extend shelf life and enhance cooking properties. Knowing this and the difference in complexity, we can begin to understand the logic in that argument, but where its flawed is the actual difference between the two. Most white rice in the US is enriched, meaning iron and some of the B-vitamins including thiamine, riboflavin, niacin and folic acid are added to white rice to boost the nutrient content.
As you can see, there’s not much differences, where the difference lies is back to its complexity. Since, unrefined starchy carbs are more complex, it takes longer to metabolize and digest thus keeping us fuller longer. Refined carbs are passed off as empty carbs because of how quickly some people get hungry soon after eating them, causing them to eat again and potentially overeat. If someone is looking to lose fat, unrefined starchy carbs would be the better choice, someone looking to bulk would probably prefer white rice as it’ll get digested quicker.
Fats, hearing or seeing the word gives some a negative connotation, but it being one of our macros, it obviously plays an important role in our lives. Triglycerides, cholesterol and other essential fatty acids—the scientific term for fats the body can’t make on its own—store energy, insulate us and protect our vital organs. They act as messengers, helping proteins do their jobs. They also start chemical reactions that help control growth, immune function, reproduction and other aspects of basic metabolism. Fatty acid is the simplest unit of fat, just like the amino acid is the simplest unit of protein and the monosaccharide glucose is the simplest unit of carbohydrate. Fats are made up of carbon and hydrogen joined together in large groups called hydrocarbons. Hydrogen atoms bond to the hydrocarbon chain like the complexity of a carb. When hydrogens have bonded but still have available bonding spots, it’s considered as unsaturated fats, they usually stay liquid at room temperature such as oils, the less saturated the fat, the more fluid it is. Unsaturated fatty acids can be broken down into 2 groups:
- Monounsaturated fatty acids: Only one carbon is unsaturated.
- Canola oil
- Almond butter
- Olive oil
- Egg yolk
- Chicken and duck fat
- Peanut oil
- Polyunsaturated fatty acids: More than one carbon is unsaturated.
- Fish oil
- Corn oil
- Hemp oil
- Flaxseed oil
- Grapeseed oil
- Walnut butter
If hydrogens have filled up all the available bonding spots on the chain, the fat is considered saturated. Saturated fats are usually solid or semi-solid at room temperature. Examples of saturated fats include:
- Coconut oil
- Beef, lamb, pork fat
- Kernel oil
- Whole fat milk, cheese, and yogurt
When 3 fatty acids join with a glycerol molecule, it forms a triglyceride. Triglycerides are the major form of fat in the diet, and the major storage form of fat found in the body. Like the breakdown of carbs into glucose, triglycerides get broken down into fatty acids and glycerol with the help of an enzyme called lipoprotein lipase to pass through a cell membrane which then they are either oxidized and used to transfer energy in skeletal muscle or other tissues; or converted back into triglycerides for storage in adipose tissue (body fat), skeletal muscle, etc. Because fat doesn’t dissolve in water, it must be carried in a lipoprotein. Types of lipoproteins are:
- Low-density lipoproteins (LDL): Carry cholesterol to all cells in the body.
- High-density lipoproteins (HDL): Bring fat and cholesterol from the body’s cells back to the liver.
LDLs are often considered as the bad cholesterol because of their role in depositing cholesterol into our arteries. HDLs are good cholesterol and are considered heart healthy lipoproteins because of their role of the removal of excess cholesterol from cells, including arteries, and back to the liver.
Vitamins comes from the Latin word “vita” meaning “life”. Vitamins are organic compounds that we need to live and thrive. They participate in all metabolic processes such as growth, repair, digestion, energy transfer, nervous system function, and immunity. Vitamins are generally categorized as either fat-soluble or water-soluble.
- Fat-soluble: Are mostly absorbed in the GI tract, they usually travel bound to the dietary fats we consume, which goes back to how fats are important to us, if we don’t eat enough fat, we may not get these key vitamins. Since, these vitamins live in fatty tissues, we don’t need to consume them everyday, too much accumulation can cause toxicity. Examples of fat-soluble vitamins are:
- Vitamin A: Healthy eyes and general growth and development, including healthy teeth and skin.
- Vitamin D: Strong healthy bones.
- Vitamin E: Blood circulation, and protection from free radicals.
- Vitamin K: Blood coagulation.
- Water-soluble: In contrast to fat-soluble vitamins, water-soluble vitamins dissolve in water and are not stored, so these vitamins are something that we should include into our daily diet. Examples of water-soluble vitamins are:
- B Vitamins: Energy production, immune function, and iron absorption.
- Vitamin C: Strengthening blood vessels and giving skin its elasticity, anti-oxidant function, immune function, and iron absorption.
Minerals don’t give us energy directly but are still an essential nutrient. They help build body structures such as teeth and bones, they help regulate our body fluids, and they are co-factors in enzymatic reactions. Minerals are absorbed in our small intestine, they are already in its simplest form so they don’t need to be broken down nor will they break down when heated (cooking) compared to vitamins. We do however lose the amount of minerals in certain foods, depending how they are prepared, particularly processed foods. Like nutrients, we can classify minerals into macro and micro doses.
- Macrominerals: Macrominerals such as calcium, magnesium, sodium (salt), potassium and phosphate are needed in bigger amounts for proper health. One would think we’d need to intake as little sodium as possible, we do need to limit our intake, but we also need it to help generate and regulate electrochemical impulses in our bodies, being that sodium is a good conductor for electricity (electrolytes). We need mineral-based electrolytes such as calcium, magnesium, sodium, potassium and phosphate to contract and relax our muscles, balance our body fluids, and shoot signals across our nerve cells. The problem with sodium intake is when we take too much of it or if we don’t drink enough water to maintain proper pH. Drinking too much water and not enough sodium can lead to hyponatremia (water poisoning) which is dangerous and can potentially be fatal.
- Calcium: Healthy teeth and bones.
- Magnesium: Nerve function, immune function, a healthy heartbeat and strong bones. It is also part of more than 300 biochemical reactions in the human body.
- Sodium: One of the electrolytes to regulate the transportation of fluids, nutrients and waste to and from your cells.
- Potassium: One of the electrolytes to regulate the transportation of fluids, nutrients and waste to and from your cells.
- Phosphate: Bone health and provides energy to cells.
- Microminerals: Microminerals such as zinc, iron, copper, manganese, chromium, selenium, and iodine are needed in far smaller quantities.
- Zinc: Immune function, normal growth and development, and helps maintain your sense of smell and vision.
- Iron: Helps red blood cells transport oxygen throughout your body and helps carry carbon dioxide out.
- Copper: Our bodies use copper to produce connective tissues and healthy bones.
- Manganese: Supports enzyme functions and helps our bodies absorb nutrients by breaking down carbohydrates and cholesterol. It’s also important for bone and joint health.
- Chromium: Chromium is involved with regulating blood sugar levels in our bodies as it appears to enhance insulin activity.
- Selenium: Antioxidant that promotes immune system strength and works with Vitamin E.
- Iodine: Promotes healthy thyroid function. It helps our bodies create thyroid hormones that regulate growth and metabolism. It is often combined with potassium to support thyroid health.
Foods contain both macro and micronutrients. The purpose of tracking macros is to calculate our total daily energy expenditure (TDEE) — roughly how much energy (k Cal) our body needs on a given day based on our basal/resting metabolic rate (BMR, RMR) — the amount of calories our bodies burn just to keep us alive, thermic effect of food (TEF) — the calories needed to burn off the food we eat, non exercise activity thermogenesis (NEAT) — our daily living such as getting out of bed, standing or sitting at work, etc., and thermic effect of physical activity (TEPA) — which is our exercise. Knowing our TDEE, we can alter our macros to suit our goals. This will give us the most consistent and sustainable diet. Just like different people can have different results with certain types of resistance training, one diet that works for someone may not work for another even though they have similar goals and even body types. Nutrition is a continuous trial and error process, especially since what we’re tracking, isn’t the exact numbers we’re actually taking in. Whether you’re looking to cut fat or gain mass, the best approach is to take things slowly, putting yourself in a slight deficit (below TDEE) or slight surplus (above TDEE) and see how it works for you. Putting yourself into too much of an extreme at either end can leave you malnourished, messing up your metabolism and leading to muscle wasting or fat gain. While doing these calculations, you might even realise that you’re not even meeting your TDEE, so you might have to ramp yourself up to your maintenance level (TDEE), to reset your metabolism, then go from there.
This is just the basics of nutrition; nutrition coaching is the best bet to familiarize yourself with everything and find out what works for you. Overtime, you’ll learn your macros, what your ideal portion sizing is, and meal timing, then doing it on your own will be a breeze!
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