What are Macronutrients, Anyway?

Eating is an essential part of life and plays a role in our social, physical and mental well-being. Yet sometimes we pay little attention to nutrition and don't understand the basic building blocks of food. All food is comprised of calories from protein, carbohydrates, fats, or a combination of these elements.

Water doesn't supply energy in the form of calories, but it is absolutely vital to the human body. Food also supplies essential vitamins and minerals in varying amounts.

To gain a better understanding how food affects your body, you need to become familiar with the basic fundamentals of nutrition:




Calories

A calorie is a unit of energy present in all food, including proteins, fats and carbohydrates. Fats contain nine calories per gram, while carbohydrates and proteins contain four calories per gram.

The process of digesting protein, carbohydrates, or fat provides energy to our bodies. This energy is commonly measured in calories. The first principle of good nutrition is eating food that provides enough energy (calories) for your body's daily needs.

The number of calories your body needs each day depends on a lot of factors and can range from under 1000 to over 3000 calories per day, depending on your age, gender, and body size. The energy density of all carbohydrates (except fiber) and all proteins is about the same: 4 calories per gram. That equal about 110 calories per ounce, or 450 calories in a quarter-pound portion.

All fats, on the other hand, provide 9 calories of energy per gram, which is 250 calories per ounce or 1000 calories in a quarter pound. That is more than twice as many calories as protein or carbohydrates!

Alcohol also provides calories (7 per gram), but since alcohol has a lower boiling point than water it is generally cooked out of food (evaporated) before it is eaten, and therefore alcohol is not usually important to food nutrition.




Proteins

Proteins are the essential building blocks of life - every cell in the body contains protein! These cells make up your skin, bones, muscle, organ issue, blood, and hormones.

The consumption of protein results in very little insulin release. Insulin regulates blood sugar and excess insulin has been known to lead to diabetes.

Lean sources of protein include low-fat cheeses, low-fat yogurt, eggs, poultry, lean meats, fish, tofu, and beans/legumes.Protein is composed of nitrogen-containing compounds called amino acids. Of the 20 different amino acids needed by our bodies, 9 are considered "essential amino acids" in that they must come directly from foods we eat (the other 11 can be made in our bodies).

Amino acids as the building blocks of proteins are composed of four chemical elements: C, H, O, N. The incomplete proteins existing in nature either lack one or more of the essential amino acids or may contain some in low quantities. In other words, there are proteins which have either an "absolute" completeness of essential amino acids or a "partial" deficiency thereof.

The proteins derived from cereals, for example, have a partial deficiency of certain amino acids like lysine and tryptophan. Therefore, by integrating the cereal proteins with those of milk, in appropriate quantities, a protein complex which is well balanced in essential amino acids is obtained.

The concept of complementarity of proteins derives from the scope of forming a complete group of essential amino acids by means of an optimal combination of partial ones.

Among the notable roles of proteins:

Consuming inadequate protein can badly affect the body’s vital functions. Excess protein in the diet on the other hand, will be stored as fat in the body, so getting the right amount of protein is an important dietary goal.



Fats

Fats when taken in moderation are important for growth, development, and absorption of fat soluble vitamins. Some dietary fats are more beneficial than others.

Monounsaturated fats are 'healthy' fats they are good for your heart and have a positive affect on blood cholesterol levels; sources include olive oil, canola oil and peanut oil. Polyunsaturated fats are needed in small amounts. Omega-3 fatty acids and Omega-6 fatty acids, found in fish, oils and nuts are two types of polyunsaturated fats that are essential to your body.

'Unhealthy' saturated fats come from butter, lards, meat fats, full-fat dairy products, and coconut oil; these foods have a negative affect on blood cholesterol.

Trans fats ('unhealthy' fats) are found in some margarine, crackers, cookies, snack foods, and any processed food made with partially hydrogenated oils.

Fats, being energy dense (high amount of calories), must be eaten in moderation - whether they are of the ‘healthy’ or ‘unhealthy’ kind.

In the body, fat is found in every cell in the body. It is also a very efficient means for storing energy, so when your body is taking in more calories (energy) than is needed, the excess energy is often stored as fat.

The positive health aspects of fats are:

Carbohydrates are a group of sugars attached together as a chain. Carbohydrates supply energy to the body but when consumed in excess, they are stored as fat.

There are two main types of carbohydrates: simple and complex. Simple carbohydrates cause a sharp rise in insulin production. This can lead to insulin resistance, which has been shown to contribute to diabetes.

They are easily digested, causing food to empty from the stomach quickly and lead to an increased feeling of hunger soon after they are eaten. Simple carbohydrates include fruit juice, sugar, and processed or enriched white grains.

Complex carbohydrates lead to less insulin production and contain fiber, an essential part of a healthy diet. They require more work for the body to break down, causing a longer-lasting feeling of satiety, or fullness.

"Carbs", as they are sometimes called, are the molecules that serve as the primary source of energy for our bodies, in part because they can be converted into energy more easily than protein or fat molecules can be.

All carbohydrates are made up of three chemical building blocks called the "simple sugars"-- glucose, fructose, and galactose.Galactose, known also as "milk sugar" comes from dairy products only. Fructose is found in fruits, honey, and refined sugar (sucrose). Glucose is the "workhorse" sugar -- amazingly, glucose molecules are the only chemical components in all types of starch molecules and all dietary fiber molecules! Glucose is also part of refined sugar and dairy products.

Starch and fiber molecules are made up of lots of glucose molecules connected to form long chains. Breaking apart the glucose chains takes energy, making starch a less efficient energy source than the simple sugars. The glucose chains in dietary fiber are formed in such a way that the body cannot break them down at all! -- that is why fiber contributes no calories or nutrition to the body.

It is important to eat enough carbs, because without a sufficient supply of carbs, digestive processes can start producing energy from protein, leaving the protein unavailable for repairs to the body.

Glucose is the only power source for the brain and central nervous system. When carb intake is adequate, the body keeps about a day's glucose needs stored in the muscles, where it is used for movement, and in the liver, which releases as much as needed for use by the brain, nerves, and other vital organs.

A reduced-calorie diet -- eating less calories than your body uses each day -- causes the body to draw on stored fat for energy (that is why you lose weight), but it is essential to always maintain adequate intake of carbohydrates (so your brain and nerves function properly) and protein (so your body can make repairs).

If your body is using fat for energy without adequate carbohydrates in the diet, a potentially serious condition known as ketosis can even result, where the blood's oxygen-carrying function becomes impaired.

It is easy to remember that carbs come from plants, if you remember that plants consume carbon dioxide and water, and that "hydro" in a word means "water". Looking at the word "carbohydrates" as "carbo + hydrates", you can see that carbon dioxide plus water is a good recipe for carbohydrates!

All that is left over is oxygen, which is "exhaled" by plants.Carbohydrates are energy-rich compounds composed of carbon, hydrogen and oxygen. They are the body’s main source of energy. During digestion, most carbohydrates are changed to simple sugar glucose.

In fact, the word glucose derives from the Greek root “glucus” which means sweet. Carbohydrates or “sugars “are widely diffused in nature and are especially found in the vegetable kingdom where they are formed, but also in supportive materials (cellulose) or in stored materials (starch).

Carbohydrates are also found in animals in the form of glucose-glycogen either in a free form or in combination with proteins, carbohydrates, fats or with other compounds of biological interest.

From a chemical point of view they are compounds known as “ternary substances” formed by the union of Carbon, Hydrogen, and Oxygen although in the composition of some, other elements are present such as sulphur and nitrogen.

Carbohydrates are classified in:

Carbohydrates are burned faster than proteins and fats, thus allowing the latter two to be saved from combustion, thereby demonstrating to have a significant function as preservers of energy.

When the body's energy requirements are met, the excess amount of carbohydrates consumed are partly stored in the liver and muscle cells (glycogen) as energy material and partly transformed in fats to be used for energy for other needs. They also have a plastic function since they fall within the context of essential structures for living organisms (nucleic acids and brain lipids).



Water

Water is a basic component to all of your body's functions. Your body’s total weight is 55-75% water - including 70% of your brain, 82% of your blood and 90% of your lungs.

The absence of water is more life threatening within a shorter period of time than solid food fasting.

That's why it's essential to consume a minimum of 64 ounces of water daily to prevent dehydration. You need even more than this amount during hot summer months and during physical activity.Your body cannot survive for more than five days without water, but dehydration sets in much more quickly.

Symptoms of dehydration include:

Water has numerous biological functions:

The presence of water in the body can be divided in two large categories of function: intercellularwhich comprises about 50% of total body weight and extracellular which corresponds to 20% of total body weight of which 5% is water from blood and 15% is interstitial water.

The greatest portion of water in the humans derives from exogenous sources. It is therefore introduced into the body through the intake of food and drinks. The remaining portion has an endogenous origin and is formed as a final catabolic product in the oxide-reduced processes.