Understanding Macronutrients: Essential for the Body

by Johnny Jacks
Macronutrients constitute a category of nutrients that supply the body with energy and essential components to uphold its structure and functionality. Let’s delve into a comprehensive understanding of this nutrient and discern it from micronutrients.

Understanding macronutrients

Our bodies necessitate adequate quantities of nutrients to facilitate functions such as growth, repair, and protection against disease-causing bacteria. There exist two distinct types of nutrients, namely macronutrients and micronutrients. While the body only requires minimal amounts of micronutrients, the demands for macronutrients are significantly higher.

Learn about macronutrients. (Photo: Internet Collection)

Learn about macronutrients. (Photo: Internet Collection)

What are macronutrients? They constitute a group of nutrients that the body requires in substantial quantities, playing a vital role in providing energy and other essential components for maintaining structure and function. The primary macronutrients include carbohydrates, proteins, and fats.

Macronutrients also supply energy in the form of calories. Carbohydrates serve as the main energy source. The calorie content per gram for each macronutrient, according to data from the US Department of Agriculture, is as follows:

  • Carbohydrates: 4 calories per gram.
  • Protein: 4 calories per gram.
  • Fat: 9 calories per gram.

What is included in macronutrients?

Macronutrients consist of three primary types, each playing specific roles in ensuring proper bodily functions.

Carbohydrates (Carbs)

Carbohydrates (carbs) are significant macronutrients encompassing starch, sugar, and fiber.

The macronutrient carbohydrates. (Photo: Internet Collection)

The macronutrient carbohydrates. (Photo: Internet Collection)

What are carbohydrates, a type of macronutrient?

Carbohydrates are a category of macronutrients present in various foods and beverages. Most carbohydrates naturally occur in plant-based foods, such as grains, while food manufacturers also incorporate them into processed foods in the form of added starches or sugars.

This nutrient is divided into two categories, including simple carbohydrates and complex carbohydrates.

Simple Carbohydrates: These are easily digestible carbohydrates that the body breaks down into glucose for energy. They consist of 1-2 sugar molecules and are present in many sweets, including honey, yogurt, and fruits.

Complex Carbohydrates: Compared to simple carbohydrates, complex carbohydrates take longer for the body to break down. They contain 2 or more sugar molecules and are abundant in starchy foods and grains.

Carbohydrates serve several essential functions, including:

  • Instant energy for the body: Glucose serves as the preferred energy source for the brain, central nervous system, and red blood cells.
  • Energy storage: Glucose is stored as glycogen in the muscles and liver for use when the body requires energy.
  • Facilitates healthy digestion: Fiber promotes regular bowel movements.
  • Promotes prolonged satiety: Fiber helps you feel fuller for longer, aiding in weight management.

How does the body absorb carbohydrates?

Before the body can utilize food, it must be broken down into its basic nutritional constituents. At this stage, the digestive system functions akin to a large food processor. During digestion, both mechanical (chewing) and chemical (by enzymes) processes break down starches and sugars into glucose and fructose units, which are then absorbed into the bloodstream and transported for use as energy by the active body.

Mechanism of carbohydrate absorption. (Photo: Internet Collection)

Mechanism of carbohydrate absorption. (Photo: Internet Collection)

The digestion of starch into glucose molecules initiates in the mouth but primarily occurs in the small intestine through the action of specific enzymes secreted by the pancreas, such as α-amylase and α-glucosidase.

The end products of the digestion of sugars and starches are simple sugars, namely fructose and galactose. Glucose, fructose, and galactose are absorbed across the membrane of the small intestine and subsequently transported to the liver or distributed throughout the rest of the body.

Various factors indeed influence the body’s absorption of carbohydrates, including:

Detail Example
Cooked Less processed foods are digested more slowly and have a lower glycemic index (GI) compared to cooked or highly processed foods. Cooked oats or brown rice have a lower GI than instant oats or brown rice.
Fiber Fiber aids in slowing down the digestion of carbohydrate-containing foods. High-fiber foods generally exhibit a lower GI than low-fiber foods. Whole-grain breads, oats, and lentils have a lower GI than low-fiber foods such as white bread and rice cereals.
Fats and Proteins Consumption of fat or protein with carbohydrates decelerates digestion and reduces the GI of the carbohydrate. Snacks comprising carbohydrates with protein or fat tend to have a lower GI than snacks containing carbohydrates only. For instance, crackers with peanut butter have a lower GI compared to consuming just crackers.
Acids in Foods Acids in foods contribute to lowering the GI of foods containing carbohydrates. Incorporating vinegar, lemon juice, or citrus fruits into foods can effectively reduce their GI.

Amount of carbohydrates your body requires daily

As per recommendations from the US, carbohydrates should make up 45-65% of the total daily caloric intake. Therefore, if your daily calorie requirement is 2,000 calories, then 900-1300 calories should be derived from carbohydrates (equivalent to approximately 225-325g of carbohydrates per day).

Note: 100 grams equals 0.22 pounds.

Foods abundant in carbohydrates

Noteworthy sources of carbohydrates comprise:

  • Whole grains: Brown rice, oats, bread, and barley.
  • Vegetables: Peas, potatoes, corn, and other starchy vegetables.
  • Fruits: Mango, banana, fig, and apple.
  • Legumes and pulses: Black beans, lentils, and chickpeas.
  • Dairy products: Milk and yogurt.

Macronutrients: Proteins

Proteins are key components within the macronutrient group, significantly contributing to the body’s essential functions.

Protein is crucial for the body.

Protein is crucial for the body.

What are proteins?

Proteins are present throughout the body, from muscles and bones to skin and hair. Comprising more than 20 fundamental building blocks known as amino acids, proteins serve various essential functions.

Proteins have four primary roles, including:

  • Cell Building and Repair: Amino acids aid in the production of new proteins, crucial for tissue and muscle repair and development.
  • Body Growth and Maintenance: Amino acids contribute to the structural composition of cell membranes, organs, hair, skin, and nails.
  • pH Balance: Amino acids help regulate the body’s acid-base equilibrium.
  • Enzyme and Hormone Synthesis: A balanced supply of amino acids is necessary for the body to produce enzymes and hormones effectively.

How does the body absorb protein?

Protein macronutrients are also absorbed in the small intestine, which contains microvilli, enhancing the absorptive surface area. This mechanism enables the body to optimize the absorption of amino acids and other vital nutrients.

Daily protein requirements

The recommended protein intake varies based on individual factors such as weight and age group.

Protein requirements vary for each individual. (Photo: Internet Collection)

Protein requirements vary for each individual. (Photo: Internet Collection)

Average protein/day: Nutritionists suggest that approximately 10-35% of your daily calorie intake should be from protein. For instance, if your daily caloric requirement is 2,000 calories, then 200-700 calories from this macronutrient would be suitable (equivalent to 50-175g). The recommended protein intake for adults is 0.8g per 1kg of body weight.

Age 40-50: As one ages, protein needs typically increase to approximately 1-1.2g per kg of body weight within the 40-50 age group.

Highly active individuals: Those who engage in regular physical activities require higher protein intake compared to the average person, approximately 1.1–1.5g per kg of body weight. Individuals who regularly participate in weightlifting, jogging, or cycling might need about 1.2–1.7g per kg of body weight. However, protein consumption should not exceed 2g per kg of body weight.

Note: 1 kilogram equals 2.20 pounds.

For individuals struggling with weight issues, it is essential to carefully monitor protein intake. For accurate advice and effective guidance, consulting a healthcare professional directly is highly recommended.

Protein-rich foods to incorporate into your diet:

A wide array of foods are excellent sources of protein and can be effortlessly integrated into your daily meals, including:

Foods high in protein. (Photo: Internet Collection)

Foods high in protein. (Photo: Internet Collection)

  • Poultry: Chicken and turkey.
  • Eggs: Particularly egg whites.
  • Red meat: Beef, lamb, and pork.
  • Seafood: Salmon, shrimp, and cod.
  • Dairy products: Fresh milk, yogurt, and cheese.
  • Beans and legumes: Black beans, lentils, and chickpeas.
  • Nuts: Almonds and pumpkin seeds.
  • Soybean products: Tofu and Japanese soybean edamame.

Fat – an essential macronutrient

Fat constitutes one of the three primary macronutrient categories necessary for the body, comprising fundamental structural units known as fatty acids (saturated or unsaturated).

Foods containing healthy fats are beneficial for the body.

Foods containing healthy fats are beneficial for the body.

What is fat?

Fat falls under the category of energy-providing substances and is a type of lipid that encompasses a group of compounds soluble in organic solvents, typically insoluble in water, and less dense than water.

Some key functions of fat in the body include:

  • Contribution to bodily structure: Indeed, 18-24% of body weight comprises fat, an essential constituent of cell membranes.
  • Energy storage: Fat is distributed throughout the body, serving as an energy reserve available for use during periods of heightened demand.
  • Enhanced absorption of vitamins: Fat acts as a solvent, aiding in the absorption and transportation of vital vitamins such as vitamin D, vitamin K, and vitamin E.

How does the body absorb fat?

The digestion process of lipid macronutrients occurs sequentially from the mouth to the stomach and then to the small intestine. In the oral cavity, fat digestion takes place gradually, primarily through chemical breakdown facilitated by the enzyme lipase.

Only a small portion of fat is digested in the stomach; the majority of digestion occurs in the small intestine. At this stage, fats undergo transformation until they are broken down into individual fatty acid units.

Recommended fat intake

The required fat intake varies for each individual. For adults, 20-35% of the total daily calories should come from fat (equivalent to 44-77g of fat per day for a 2,000 calorie diet).

Recommended body fat percentage. (Photo: Internet Collection)

Recommended body fat percentage. (Photo: Internet Collection)

There are beneficial fats that should be incorporated into our diet, as well as “unhealthy” fats that should be limited or eliminated:

  • Monounsaturated fats: 15% to 20%.
  • Polyunsaturated fats: 5% to 10%.
  • Saturated fat: less than 10%.
  • Trans fat: 0%.
  • Cholesterol: Less than 300 mg per day.

Fatty food sources

A variety of food sources rich in macronutrients are available. To increase healthy fats in your diet, consider incorporating the following foods:

  • Pure olive oil.
  • Coconut: Fresh coconut, dried coconut, and coconut oil.
  • Avocado: Fresh avocado and avocado oil.
  • Nuts: Almonds and pumpkin seeds.
  • Fatty fish: Salmon and herring.
  • Dairy products: Full-fat yogurt and cheese.

Water – The Calorie-Free Macronutrient

Water falls under the category of macronutrients and is an essential daily requirement in large quantities. On average, men require approximately 3.7 liters of fluids per day, while women require about 2.7 liters. Fluids encompass water, beverages, and water-rich foods. Roughly 20% of the daily fluid intake is derived from food, with the remainder sourced from drinks.

Water is essential for the body. (Photo: Internet Collection)

Water is essential for the body. (Photo: Internet Collection)

The necessary amount of daily water intake is contingent upon various factors such as temperature, physical activity, and living and working conditions.

Despite being a macronutrient that does not yield calories, water plays a crucial role in maintaining the body’s overall well-being, including the transportation of nutrients, provision of essential oxygen to cells, and supply of minerals, among other functions.

Read more: Battling Belly Fat: Root Causes and Solutions

How are macronutrients distributed in the diet?

Each macronutrient serves a crucial role in optimizing bodily functions. It’s essential to design a well-balanced diet that incorporates an adequate amount of carbohydrates, proteins, and fats from diverse food sources.

Distribute nutrients for a balanced diet. (Photo: Internet Collection)

Distribute nutrients for a balanced diet. (Photo: Internet Collection)

Individual macronutrient requirements vary depending on factors such as activity level and age. According to the dietary guidelines from the United States Department of Agriculture (USDA), the recommended daily intake of each macronutrient is as follows:

  • Carbohydrates: 45–65% of total daily calories.
  • Protein: 10–35% of total daily calories.
  • Fat: 20–35% of total daily calories.

Refer to the table below for calorie requirements across various age groups, based on the recommendations from the US Office of Disease Prevention and Health Promotion (ODPHP):



Sedentary children aged 2-8 years


Active children aged 2-8 years


Girls aged 9-13


Boys aged 9-13


Active females aged 14-30


Sedentary females aged 14-30


Active males aged 14-30


Sedentary males aged 14-30


People over 30 engaged in physical activity


Sedentary individuals over 30


What is the distinction between macronutrients and micronutrients?

Both are vital for the proper functioning of cells in the body, but macronutrients and micronutrients differ in certain aspects. Understanding this dissimilarity will assist you in identifying the essential food groups for maintaining a balanced daily diet.

Differentiate between macronutrients and micronutrients. (Photo: Internet Collection)

Differentiate between macronutrients and micronutrients. (Photo: Internet Collection)

Here is a summary table that outlines the disparity between macronutrients and micronutrients:




Body needs

The body requires large quantities.

The body requires very small amounts.

Main function

Provides energy to the body.

Prevents diseases.

Consequences if there is a shortage

Malnutrition leading to edema (Kwashiorkor) and atrophy (Marasmus).

Conditions such as anemia, goiter, and rickets.

Consequences of consuming too much

Increased risk of heart disease, diabetes, and obesity…

Can cause harm to the liver and nervous system.


Includes carbohydrates (carbs), proteins, and fats.

Encompasses antioxidants, minerals, and vitamins.


Found in grains, fish, legumes, meat, nuts, potatoes, and more.

Obtained from fruits, vegetables, eggs, fermented foods, and green leafy vegetables, among others.


Provides the necessary energy for the body’s metabolic processes.

Contributes to body growth and aids in disease prevention.

Macronutrients are highly important and simple to incorporate into your daily diet. Ensure to include them in every meal for yourself and your family to establish a well-rounded and nourishing diet. Best wishes and remember to explore more valuable information on our website!

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