What is Macronutrients - What are Carbohydrates, Fat and Proteins, Their Types, Functions, Benefits

Introduction:

Macronutrients or macros are carbohydrates, fats, and protein. With the term macro meaning very large, these three nutrients are responsible for providing calories. Anything you eat is broken down to these three macronutrients. Your body does not recognize the food you eat as chicken, rice, salad etc. Instead, your body sees whatever you consume as a carb, fat, or protein. This is the reason you find these macronutrients written in bold letters on the nutrition label of any food or drink product.

To comprehend how good nutrition helps keep your body healthy, it’s a good idea to start with the basics: macronutrients and micronutrients. Macronutrients are carbohydrates, fat, and protein thebnutrients you need in relatively large amounts. By contrast, vitamins and minerals and other substances are deemed micronutrients, because you need them in smaller amounts. Every day, it seems, a new nutrient is touted as the key to good health—there are diets that revolve around lean protein, fiber, omega-3 fats, antioxidants, vitamin D, and much more. In reality, what you need is the right mix of nutrients. In this section, we’ll give you a quick overview of each one and what you really need.

Carbohydrates:

In recent years, carbohydrates or carbs have endured close scrutiny and extensive debate as low-carb diets have captured the public’s attention. As a result, many people have come to believe that carbohydrates are inherently bad. But that’s not the case. In fact, the main function of the simple sugars and starches in the foods we eat is to deliver calories for energy. Our body breaks them down into glucose or blood sugar. Glucose is essential for the functioning of the brain, nervous system, muscles, and various organs. The simple sugar glucose is required to satisfy the energy needs of the brain, whereas our muscles use glucose for short-term bouts of activity. The liver and muscles also convert small amounts of the sugar and starch that we eat into a storage form called glycogen. After a long workout, muscle glycogen stores must be replenished. Both simple and complex sugar provide about 4 calories per gram.

If carbs provide energy and you use energy in every aspect of your daily life, then knowing which foods are carbs and when to eat them is worth taking a little time to learn. Understanding the power of carbs allows you to take full control of your energy levels and make smarter food choices throughout the day. Because carbohydrates serve primarily as sources of calories, no specific requirement has been set for them. But health experts agree that we should obtain most of our calories about 60 percent from carbohydrates. Our individual requirements depend on age, sex, size, and activity level.

It is recommend that 45 to 65% of children’s, teens’, and adults’ total calories come from carbs, though pregnant and lactating women need more. If your diet has 1,800 calories per day, then you should eat about 200 g of carbs daily. Most of these carbs should come from whole grains, fruits, and vegetables, rather than sodas, baked snacks, ice cream, and sweets. In contrast to the other carbohydrates, fiber a substance contained in bran, fruits, vegetables, and legumes is a type of complex carbohydrate that cannot be readily digested by our bodies. Even though it isn’t digested, fiber is essential to our health. Nutrition professionals recommend 25 to 30 grams of fiber daily.

The carbohydrates are a vast and diverse group of nutrients found in most foods. There are two types of carbs, simple and complex. Neither simple nor complex carb is bad for you. They can both be used to your advantage throughout the day. Although both simple and complex carbs are eventually broken down to sugar in the body, digestion and absorption are the main differences between the two types. The glycemic index and glycemic load can be helpful tools to identify the best types of carbohydrates to eat.

Simple Carbohydrates:

Simple carbohydrates are chemically made of just one or two sugars. They can generally form crystals that dissolve in water and are easily digested. Simple sugars make foods sweet. A simple carb supplies your body with quick energy, but doesn’t last long. One of the most beneficial times to consume carbs is in the morning. This is mainly because chances are you’ve been sleeping for the past few hours and haven’t had anything to eat. Therefore, it is ideal to consume simple carbs for the immediate energy. Simple carbs include foods such as fruits, white bread, white rice, white potatoes, vegetables, juice, pop tarts, etc. Processed sugars include table sugar, brown sugar, molasses, and high fructose corn syrup.

They are small molecules found in many foods and in many forms such as glucose, fructose, lactose, sucrose, etc. Some simple sugars occur naturally in foods. Fructose is the sugar that naturally gives some fruits their sweet flavor. Sugar that we spoon onto our cereal and add to the cookies we bake, also called sucrose. Sucrose is most often used to sweeten carbonated beverages and fruit drinks, candy, pastries, cakes, cookies, and frozen desserts. Sucrose actually consists of a molecule of fructose chemically linked to a molecule of another simple sugar called glucose. As an additive to many different types of prepared or processed foods, sucrose adds nutritive value in the form of calories only, flavor, texture, and structure, while helping to retain moisture. Other forms of sucrose include brown sugar, maple syrup, molasses, and turbinado sugar. While lactose, the sugar that gives milk its slightly sweet taste. It consists of glucose linked to yet another simple sugar called galactose. The inability to digest lactose is the cause of lactose intolerance, a condition common to Asian, Mediterranean, and African ancestry.

Foods that are high in added sugar are often low in essential nutrients such as vitamins and minerals. Unfortunately, these foods are often eaten in place of more nutrient rich foods such as fruits, vegetables, and low fat whole grain products, and they may prevent us from obtaining essential nutrients and lead to weight gain. Reducing the amount of added sugar in your diet is a quick way to reduce calories without cutting out a lot of important nutrients. It is recommends that most women limit themselves to 100 calories a day from added sugar, men to no more than 150 calories.

Most of the sugar in diets is added during food processing at the manufacturer, even to foods we don’t think of as sweet. It’s hard to overdo it with foods that contain natural sugars; you’d have to eat a lot of fruits and vegetables to equal the amount of sugar in one piece of candy or one can of soda. When examining food labels for added sugar, look for the words corn sweetener, corn syrup, or corn syrup solids as well as high-fructose corn syrup. Also look for other words ending in ose like sucrose, lactose, maltose, glucose, and dextrose.

Complex Carbohydrates:

Complex carbohydrates are long chains of molecules of the simple sugar glucose. A complex carb takes longer to break down in your body, yet is a long-lasting source of energy. If you plan on being out of the house for a few hours, complex carbs would be a good choice for its long-lasting steady energy. So incorporating both types of carbs in your diet can allow you to better control your levels of energy throughout the day. Examples of complex carbs include whole grains such as whole wheat bread, oatmeal, and brown rice along with other foods such as sweet potato and beans.

Complex carbohydrates are made of complex chains of sugars and can be classified as starches or fiber. Our digestive system can metabolize most starches but lacks the enzymes needed to break down most fiber. But both are important to good health. Starches and fiber are naturally found in most grains and vegetables and some fruits, which also provide essential nutrients such as B vitamins, iron, and other minerals. Unprocessed whole grains are the best source.

Starches provide glucose for energy. Starch is the form of carbohydrate that is found in grains, some fruits and vegetables, legumes, nuts, and seeds. It provides energy for newly sprouting plants. Starches are digested by our bodies into their constituent glucose molecules and used for energy. Starch, like simple sugars, provides 4 calories per gram. Like simple sugars, the role of starches in our diets is mainly to provide energy.

Fiber is the tougher material that forms the coat of a seed and other structural components of the plant. Fibers provides no calories. Fiber is actually a family of substances found in fruits, vegetables, legumes, and the outer layers of grains. It is divide fiber into two categories. One is those that do not dissolve in water called insoluble fiber and those that do called soluble fiber. Insoluble fiber, also called roughage, includes cellulose, hemicellulose, and lignin, found in vegetables, nuts, and some cereal grains. Soluble fibers include pectin, found in fruits, and gums, found in some grains and legumes.

Dietary fiber promotes colon function and may help prevent some types of cancer, heart attacks, and other diseases. Fiber appears to sweep the digestive system free of unwanted substances that could promote cancer and to maintain regularity and prevent disorders of the digestive tract. Fiber also provides a sense of fullness that may help reduce overeating and unwanted weight gain. Diets that are rich in fiber and complex carbohydrates have been associated with lower serum cholesterol and a lower risk for high blood pressure, coronary artery disease, and some types of cancer.

Major studies show that women and men who eat more whole grains have 20 to 30% less heart disease. On the other hand, choosing refined grains such as white bread, sugary cereal, white rice, or white pasta can boost your heart attack risk by up to 30%. And refined grains are associated with insulin resistance and high blood pressure. The refining process removes fiber and many essential nutrients, making refined grains too easy to digest and thus flooding the body with too much glucose. Whole grains should account for at least half of all grain foods. When shopping for whole grains, don’t be fooled by deceptive label claims such as made with wheat flour or seven grain. They’re just the same old refined stuff. Instead, look for a fiber content of at least 3 g per serving. In addition to unprocessed grains, get plenty of legumes, beans, and raw or slightly cooked vegetables and fruits.

Certain diseases may require adjustments to carb intake:

Diabetes: 

Sugar does not cause diabetes, nor do people with diabetes have to completely avoid sugar. But people with diabetes must manage the total amount and type of carbs they eat at each meal and snack. Knowing the glycemic index or glycemic load.

Heart disease: 

People with heart disease need to emphasize high-fiber, complex carbohydrates in their diet. Soluble fiber, found in oat bran and fruit pectin, helps lower cholesterol and plays an important role in preventing atherosclerosis.

Cancer. 

People with cancer are often advised to increase their carbohydrate intake and decrease fat intake, especially if they have cancers of the breast, colon, uterus, prostate, or skin. Those carbs come from high fiber and antioxidant rich whole grains, fruits, and vegetables.

Fat:

It’s difficult to read a newspaper or listen to the evening news without hearing something new about fat and its connection with disease. Not only are fats a more concentrated source of calories than carbs or protein, but fat is also your body’s secondary source of energy. Studies indicate that the body more readily stores fats. When your body doesn’t have enough carbs readily available, it uses fat as another source of fuel. So a diet rich in high fat foods makes you gain more weight. Therefore, the idea of burning fat is to limit the amount of primary energy i.e. carbs, so the body can use its secondary source for energy i.e. body fat. But the truth is that fat, in small amounts, is essential to health. Foods that contain a high amount of fat include butter, peanut butter, oils, avocado, and nuts.

Fats are molecules made of fatty acids, chain-like molecules of carbon, hydrogen, and oxygen linked in groups of three to a backbone called glycerol. When we eat foods that contain fat, the fatty acids are separated from their glycerol backbone during the process of digestion. Fats add flavor and a smooth, pleasing texture to foods. Because they take longer to digest, fats let us feel full even after the proteins and carbohydrates have left our stomach. It stimulate the intestine to release cholecystokinin, a hormone that suppresses the appetite and signals us to stop eating.

Fats supply the fatty acids that are essential for numerous chemical processes, including growth and development in children, the production of steroid hormones testosterone, progesterone, estrogen, and then hormone like prostaglandins, the formation and function of cell membranes, and the transport of other molecules into and out of cells. Dietary fats also permit one group of vitamins, the fat-soluble vitamins like A, D, E, and K, to be absorbed from foods during the process of digestion. Fats help these vitamins to be transported through the blood to their destinations. The fat in our bodies also provides protective insulation and shock absorption for vital organs. A tablespoon of vegetable oil is sufficient to transport all the fat-soluble vitamins we need in a day.

Consuming low amounts of fat over time can cause hormone levels to become unbalanced, making it important to get enough even while trying to burn fat. Some types of fat have been implicated in a higher risk of heart attack, diabetes, and other diseases. Diets that are high in fat are strongly associated with an increased prevalence of obesity and an increased risk of developing coronary artery disease, high blood pressure, diabetes mellitus, and certain types of cancer.

Some fats, like those found in fish and olive oil, actually lower your risk of heart disease and can even help you stick to a weight loss plan. The amount of fat needed daily can vary anywhere from 15% to over 40% of total calories depending on the individual and fitness goal. If you’re getting 2,000 calories per day, that works out to 44 to 78g of fat daily, most of it ideally the unsaturated kind. They also recommend that we limit our intake of saturated fat to less than 10 percent of our fat calories and try to be sure that the fat we do eat is mostly the monounsaturated or polyunsaturated type. These changes have been shown to decrease our risk for several diseases.

The fat in food supplies about 9 calories per gram, more than twice the number of calories as the same amount of protein or carbohydrate. Volume for volume, however, the calorie count can differ substantially. For example, a cup of oil weighs more and therefore has more calories than a cup of whipped margarine. As a result, high-fat foods are considered calorie-dense energy sources. Any dietary fat that is not used by the body for energy is stored in fat cells i.e. adipocytes, the constituents of fat adipose tissue.

Our health is influenced by both the amount and the type of fat that we eat. Fats are molecules; they are classified according to the chemical structures of their component parts. But you don’t need to be a chemist to understand the connection between the various fats in foods and the effect these fats have on the risk for disease.

As with carbohydrates, the type of fats we eat is more important than the total amount. Different types of fats include saturated, polyunsaturated, monounsaturated, and trans fat. Most foods naturally contain both saturated and unsaturated fat but are higher in one. But trans fats rarely found in nature. It is recommended to stay away from trans fat due to its health disadvantages. Many commercially produced foods are made with trans fats. While each type of fat has its pros and cons, it is useful to pay attention to the total amount of fat in a product.

Saturated Fats:

Saturated fatty acids, or saturated fats, consist of fatty acids that are saturated with hydrogen. Saturated fats generally come from animal sources, but there are some plant sources as well. Common sources of saturated fat include meat, poultry, butter, cheese, coconut, palm oils. dairy products, eggs, and palm kernel oil often called tropical oils. Most saturated fats are solid at room temperature.

A diet high in saturated fats can raise blood cholesterol levels, one of the leading risk factors for heart disease. Saturated fat has also been linked to other health problems, such as colorectal, prostate, and ovarian cancer. Because a high intake of saturated fats increases your risk of coronary artery disease. Experts recommend that no more than 10% of your daily calories come from saturated fat, especially animal fats. Saturated fat in coconut oil increases good HDL cholesterol as well as bad LDL cholesterol.

Unsaturated Fats:

In general, unsaturated fats are healthier than saturated fats; they either lower blood cholesterol or have no effect on it, and may also help lower blood sugar and blood pressure. Most unsaturated fats are liquid at room temperature and solid or semisolid under refrigeration. Unsaturated fats fall into two main categories: monounsaturated and polyunsaturated. Each type affects your health in different way.

Monounsaturated fatty acids are fatty acids that lack one pair of hydrogen atoms on their carbon chain. They are liquid at room temperature. Foods rich in monounsaturated fatty acids include olives, nuts, avocados, and olive, canola, and peanut oil. This type of diet is commonly eaten by people who live in the region surrounding the Mediterranean Sea. Monounsaturated fats improve blood cholesterol levels and may benefit insulin levels, thus lowering your risk of heart disease and type 2 diabetes. Diet linked to a lower risk of coronary artery disease.

Polyunsaturated fatty acids lack two or more pairs of hydrogen atoms on their carbon chain. They are also liquid at room temperature. Safflower, sunflower, sesame, corn, and soybean oil are among the sources of polyunsaturated fats. The essential fatty acids, linoleic and linolenic acid, are polyunsaturated fats. Like monounsaturated fats, polyunsaturated fats lower blood cholesterol levels and are an acceptable substitute for saturated fats in the diet. Polyunsaturated fats are divided into omega 3 and omega 6 fats. While there are a variety of opinions on the optimal ratio of omega-3 to omega-6, experts agree that we tend to eat far more omega-6 fats than we need and too few omega-3s.

Omega-3 fatty acids are a class of polyunsaturated fatty acids found in fish like tuna, mackerel, and salmon, in particular and some plant oils such as canola oil. Omega-3 fats help steady heart rhythm, lower artery-clogging triglycerides, cool chronic inflammation in the arteries, prevent blood clotting, and produce a modest drop in blood pressure, all of which cut your risk of a heart attack or stroke. These fatty acids have made the news because of the observation that people who frequently eat fish appear to be at lower risk for coronary artery disease. Omega-3 fatty acids also seem to play a role in your ability to fight infection.

Omega-6 fats, on the other hand, increase inflammation if you consume too much. Omega-6 food sources include safflower, sunflower, and corn oil, and some nuts and seeds.

Trans Fats:

Trans fats are created when a vegetable oil undergoes hydrogenation, a process that lengthens foods’ shelf life. Trans fats are found in partially hydrogenated vegetable oils, some margarines, crackers, cookies, commercially fried foods

What is Cholesterol?

Cholesterol is a waxy, fat-like substance that is a necessary constituent of cell membranes and serves as a precursor for bile acids which is essential for digestion, vitamin D, and an important group of hormones like the steroid hormones. Our livers can make virtually all of the cholesterol needed for these essential functions. Dietary cholesterol is found only in foods of animal origin, that is, meat, poultry, milk, butter, cheese, and eggs. Foods of plant origin, that is, fruits, vegetables, nuts, seeds, legumes, grains, and the oils derived from them, do not contain cholesterol.

Protein:

Protein is an essential part of our diets. Proteins are large, complex molecules resembling tangled strings of beads. Each of the beads on the string is one of a group of smaller molecules called amino acids. Amino acids are composed of carbon, oxygen, hydrogen, and nitrogen, and some contain sulfur. Using the amino acids from the protein you eat, the body makes more than 50,000 different proteins. These proteins are the main structural elements of our skin, hair, nails, cell membranes, muscles, and connective tissue. Protein is the quintessential nutrient that every cell in the human body requires for growth or repair. Complete proteins are mainly found in meats such as chicken, beef, steak, fish as well as eggs, milk, and whey protein. Foods such as grains, nuts, seeds, or legumes are considered incomplete proteins.

Our muscles, which contain some 65 percent of the body’s total protein, give our bodies their shape and strength. Proteins in connective tissues such as tendons, ligaments, and cartilage enable our skeletons to function, form internal organs, and hold the organs in place. Collagen, the main protein in our skin, provides a barrier to the invasion of foreign substances. Proteins in cell membranes determine what substances can enter and exit cells. The antibodies that protect us from disease, the enzymes needed for digestion and metabolism, and hormones like insulin are all proteins. Cholesterol travels through the bloodstream attached to lipoproteins known as fat carrying proteins. Proteins in the blood carry oxygen to all cells and remove carbon dioxide and other waste products. Other proteins called enzymes accelerate metabolic processes, and still other proteins and amino acids are hormones and neurochemicals, the substances that deliver signals throughout the body and regulate all metabolic processes. The proteins in muscle, connective tissue, and blood make up most of the protein in the body. Connective tissue made from protein forms the matrix of bones. Keratin, still another type of protein, is used by the body to make hair and nails.

The protein from the meat we ate last night is not directly incorporated into our muscles. The proteins in the foods we eat are digested first into small peptides. Some of these peptides are further digested into their constituent amino acids. Only amino acids and small peptides are actually absorbed by the small intestine into the blood stream. They are then delivered to the liver, muscles, brain, and other organs, where they are used to make new proteins or converted to other amino acids needed by those organs. During periods of growth, our bodies must manufacture and store large amounts of protein. Therefore, the requirement for protein in our diets is higher during growth. But even when we are not growing, each of the unique proteins in the body has a finite lifespan and must be replaced continuously. So the need for protein never ends.

With so many essential functions linked to protein, you might assume that it should make up the bulk of your diet, but this is not the case. It is recommended to consume at least 0.8 - 1.2 grams of protein per 1 pound of your bodyweight for optimal muscle growth. Thus, a person weighing 70 kg requires 56 g of protein per day, the amount in a 3-oz serving of chicken. With many different types of protein on the market ranging from the source, absorption rate, and process of filtration, any complete protein is beneficial for the growth and repair of muscle.

Consumption of protein should ideally be spread throughout the day. There is no specific limit to the amount of protein an individual should eat in one serving. Consumption of protein in large portions compared to small portions were produces the same results in both muscle growth and weight loss as long as the daily protein requirement is met. The most beneficial times to consume protein are before and after training. Divide your daily protein requirement into each of the meals you plan to have for the day. For example, if you know you need 150 grams of protein each day, you can split that amount into 3 meals with 50 grams of protein.

Of the 20 amino acids that make up all proteins, 9 are considered “essential” because they cannot be made in our bodies and must be obtained from the foods we eat. Of the remaining 11, some are essential for infants and persons with certain diseases. Those 11 amino acids are considered nonessential, because our bodies can make them in adequate amounts.

Just as the letters in the alphabet are joined to make words, so too are amino acids arranged in an almost infinite number of different ways to form the more than 50,000 different proteins in the body. DNA or deoxyribonucleic acid, the genetic material that is found in the nucleus of each body cell, provides the blueprint for how amino acids are arranged to form individual proteins.

Animal Protein:

Animal protein provides all nine essential amino acids in the proportions required by the body and is therefore referred to as complete, or high-quality, protein. Complete proteins are those that contain all the essential amino acids in amounts needed to synthesize our body’s proteins. The best sources of complete protein are lean meats and poultry, fish, low-fat dairy products, and eggs. Unfortunately, though, many animal proteins also come with relatively high amounts of saturated fat.

Plant Protein:

The grains and cereals group of foods, which form the base of the Food Guide Pyramid, are excellent sources of protein. But plant proteins lack one or more of the essential amino acids, they are called incomplete proteins. By eating a variety of different foods, including grains and legumes, you are likely to get all the amino acids you need and in the correct amounts. People of many cultures and vegan get adequate amounts and types of protein by eating various combinations of plant proteins including beans, corn, rice, and other cereal grains. Interestingly, many cuisines include classic combinations that do just that. Like refried beans and corn tortillas of Mexico, rice and dahl of India, tofu, rice, and vegetable combinations in Asian cuisine, chickpeas and bulgur wheat in Middle Eastern dishes. Although it is necessary to combine these foods at the same meal, nutrition experts now agree that they can be eaten at various times throughout the day.

When we eat grains and legumes, rather than foods of animal origin, we gain additional health benefits. Whole grain foods and legumes are rich in vitamins, minerals, fiber, and other substances that optimize health. Grains and legumes lack the high levels of saturated fat present in foods of animal origin, which are linked to many diseases. For example, the proteins in corn are low in the essential amino acids lysine and tryptophan, and wheat is low in lysine. In contrast, legumes tend to be rich in lysine but a bit low in methionine. Among the legumes, soybeans contain the most complete protein.