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  • Writer's pictureAli

What Are Macronutrients?

Updated: Jan 11

Macronutrients, often called "macros," are the essential nutrients our bodies need in larger quantities to function properly and maintain overall health. There are three main types of macronutrients: carbohydrates, fats, and proteins. Each macro plays a unique and important role in our body's functions, energy production, and overall well-being. 

Macronutrients make up the calories you consume. The presence of each macro in food/drink dictates its energy content. 

Eating a well-balanced diet incorporating all three macronutrients is essential for weight loss and optimal health. Let’s dive deeper into each macronutrient and discover how to structure them within your diet.


Carbohydrates often get a bad rap when it comes to fat loss. You’ve probably heard all the horror stories about carbs being the enemy and what happens if you eat them past 7 p.m. These are all false. No one macronutrient is at fault for gaining body fat - it’s purely overconsumption of calories. 

Carbohydrates are one of the body's primary sources of energy. They are found in grains, cereals, fruits, vegetables, legumes, and sugars. Carbohydrates can be simple (sugars) or complex (starches and fibre). They are broken down into glucose, which your body uses for energy.

Carbohydrate-rich foods are a crucial component of a balanced diet. The body receives glucose from carbohydrates, which is then transformed into energy for maintaining biological processes and engaging in physical activity.

It's important to note that not all carbohydrates are the same. There are simple carbohydrates (sugars) and complex carbohydrates (starches and fibre). The type and quality of carbohydrates you consume can impact their role in your diet and health. Whole grains, fruits, vegetables, and legumes are generally considered healthier sources of carbohydrates due to their fibre content and lower glycemic index. 

In contrast, added sugars and refined carbohydrates should be consumed in moderation to avoid adverse health effects such as obesity and insulin resistance. The recommended carbohydrate intake varies based on an individual's age, activity level, and specific dietary needs.

Carbohydrates provide 4 calories per gram.

The number of carbohydrates needed should make up 45-65% of your diet; otherwise can be made up with the remaining amount of calories after protein and fat have been considered.

Carbohydrates play several important roles in the human body:

Energy Source: Carbohydrates are a primary and efficient source of energy for the body. When you consume carbohydrates, they are broken down into glucose, which is then used by your cells for energy. Glucose is particularly important for providing energy to your brain and muscles.

Brain Function: Glucose, derived from carbohydrates, is the preferred source of energy for the brain. Adequate carbohydrate intake is essential to maintain cognitive function and mental clarity.

Spares Protein: When you consume enough carbohydrates, your body doesn't need to use protein for energy. This allows protein to be used for its primary functions, such as building and repairing tissues.

Supports Physical Activity: Carbohydrates are crucial for physical performance and exercise. They provide energy for muscles during physical activity, particularly in high-intensity or endurance exercises. Athletes often rely on carbohydrates as a key part of their diet to fuel their training and performance.

Regulates Blood Sugar: Carbohydrates can have an impact on blood sugar levels, and different types of carbohydrates have varying effects. Complex carbohydrates, like those found in whole grains and fiber-rich foods, are digested more slowly and can help regulate blood sugar levels, preventing rapid spikes and crashes.

Fiber and Digestive Health: Fiber, a type of carbohydrate found in plant-based foods, is essential for maintaining a healthy digestive system. It adds bulk to your stool, promotes regular bowel movements, and can help prevent conditions like constipation and diverticulosis.

Hormone Regulation: Carbohydrates can affect the release of certain hormones, including insulin. A balanced carbohydrate intake can help regulate blood sugar levels and support overall hormonal balance.


Dietary fats are essential for regulating hormonal function and providing the body with energy to operate daily. They are the most energy-dense macronutrient, weighing in at 9 calories per gram.

It's important to note that while dietary fat is essential for health and provides various benefits, it should be consumed in moderation. The type of fats you consume matters, too.

Healthy fats, such as those found in avocados, nuts, seeds, and olive oil, are preferable to saturated and trans fats, which should be limited in the diet to reduce the risk of certain health issues, such as heart disease. Balancing the types and amounts of fat in your diet is crucial for maintaining overall health and well-being.

Fat is essential for many bodily functions. Excessive accumulation of body fat, especially visceral fat (fat stored around internal organs), can be associated with health problems like obesity, cardiovascular disease, and metabolic disorders. Therefore, maintaining a healthy balance of body fat is crucial for overall well-being. The type of fats consumed also matters, with a preference for healthier, unsaturated fats over saturated and trans fats to support better health outcomes.

Fat plays several important roles in the human body:

Energy Storage: One of the primary functions of fat in the body is to serve as an energy store. When you consume more calories than your body needs, the excess energy is converted into triglycerides and stored in fat cells. These stored fat reserves can be mobilized and used for energy when needed, such as during times of calorie deficit or increased physical activity.

Insulation: Fat serves as an insulating layer beneath the skin, helping to regulate body temperature. It acts as a thermal insulator, helping to retain heat in cold environments and prevent overheating in hot conditions.

Protection: Fat can provide cushioning and protection to internal organs. It acts as a shock absorber, helping to safeguard vital organs from physical trauma.

Hormone Regulation: Fat tissue produces hormones and plays a role in regulating hormone levels in the body. For example, adipose tissue (fat cells) produces leptin, which helps regulate appetite and metabolism. It also produces adiponectin and various inflammatory substances.

Vitamin and Nutrient Storage: Fat tissue can store fat-soluble vitamins, such as vitamins A, D, E, and K. When needed, these vitamins can be released from fat stores to support various bodily functions, including bone health and immune system function.

Cell Membranes: Fats, specifically phospholipids, are crucial components of cell membranes. They help maintain the structural integrity of cells and facilitate various cellular processes.

Brain Function: The brain is composed of a significant amount of fat, and dietary fat is essential for brain function. It is particularly important for the myelin sheath that surrounds nerve cells, which allows for efficient nerve signal transmission.

Skin and Hair Health: Fats, particularly essential fatty acids, are important for maintaining healthy skin and hair. They help keep the skin moisturized and contribute to a healthy complexion.

Immune System Support: Some fatty acids, like omega-3 fatty acids, have anti-inflammatory properties and can support the immune system by reducing inflammation and promoting overall health.


Protein is essential for the growth, repair, and retention of muscle. It’s arguably the most important macronutrient where body composition improvements are concerned. 

Dietary protein is also essential because it provides the amino acids necessary for building and repairing body tissues. Amino acids that cannot be synthesized by the body and must be obtained from the diet are called essential amino acids. It's essential to consume a balanced diet that includes a variety of protein sources to ensure you get all the necessary amino acids for your body's functions. Good dietary protein sources include:

  • Meat

  • Poultry

  • Fish

  • Eggs

  • Dairy products

  • Legumes

  • Nuts and seeds

Proteins are large, complex molecules made up of amino acids and are essential components of all living organisms. They serve a wide variety of critical functions in the human body and other organisms.

Your body needs protein to support growth, repair, metabolic processes, immunity, and overall health. It's important to consume an adequate amount of dietary protein through your daily diet to meet these essential functions. 

Proteins provide 4 calories per gram.

The amount of protein a person needs can vary depending on age, sex, weight, physical activity level, and other factors. For example, athletes, bodybuilders, and people trying to lose weight or gain muscle may need more protein to support their goals. Recommended intake should be around 1.5-2g per kilogram of body weight.

Why does your body need dietary protein?

Tissue Growth and Repair: Protein is crucial for the growth, maintenance, and repair of tissues in the body. This includes the development and repair of muscles, bones, skin, hair, internal organs, and other structural components of the body.

Enzymes: Many enzymes are proteins, and they act as biological catalysts that facilitate and regulate chemical reactions in the body. Enzymes are involved in processes like digestion, metabolism, and energy production

Hormone Production: Certain hormones, such as insulin and growth hormone, are composed of proteins. These hormones play essential roles in regulating metabolic processes, growth, and overall health.

Immune System Function: Antibodies, which are specialized proteins, are key components of the immune system. They help the body recognize and defend against foreign invaders like bacteria, viruses, and other pathogens.

Transport of Molecules: Transport proteins in cell membranes facilitate the movement of molecules in and out of cells. These proteins help transport nutrients, ions, and other vital substances within the body.

Energy Source: While carbohydrates and fats are primary sources of energy, the body can use protein as an energy source when necessary. This typically occurs when there is an inadequate intake of calories from carbohydrates and fats, such as during prolonged fasting or low-calorie diets.

Structural Function: Structural proteins, such as collagen, provide strength and support to connective tissues like skin, tendons, and bones. Other structural proteins contribute to the elasticity of skin and the strength of muscles.

Neurotransmitters: Some proteins are involved in the synthesis and regulation of neurotransmitters, which are chemicals that transmit signals in the nervous system.

Maintaining Fluid Balance: Certain proteins help maintain fluid balance in the body, preventing excess fluid accumulation in tissues and contributing to proper hydration.

pH Regulation: Proteins can act as buffers to help regulate the pH (acid-base balance) of bodily fluids, ensuring that the body maintains a stable internal environment.


Written by Ali. Live in Harmony Co-Creator.


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