Everything You Need to Know About Macronutrients

Everything You Need to Know About Macronutrients

“Does it fit your macros?” is a popular question posed by many fitness enthusiasts and professionals today. But what is a macro? A “macro” is the abbreviation for macronutrient, which is a nutrient that provide calories or energy and are substances needed for growth, metabolism, and other physiological functions. There are three macronutrients that are needed in large quantity by living organisms:

  • Carbohydrates
  • Fat
  • Protein

While all macronutrients provide calories or energy, the amount of calories that each one provides varies.

Carbohydrate provides 4 calories per gram.
Protein provides 4 calories per gram.
Fat provides 9 calories per gram.

The ratio at which a person consumes macronutrients is dependent on several individual variables and desired outcomes. A person’s activity level, body composition, weight, fitness goals and general health all contribute to the total grams of each macronutrient a person should consume.  A person who is obese, sedentary, diabetic and hypertensive will have a completely differing macronutrient profile than a lean and muscular weightlifter. Tracking your macronutrient and calorie consumption can be critical to achieving your health and fitness goals.


Carbohydrates are the macronutrient that are generally needed in the largest quantity, although many individuals who desire to decrease body fat and rapidly improve body composition will choose to consume a smaller amount of carbohydrates. According to the Dietary Reference Intakes published by the USDA, 45% – 65% of calories should come from carbohydrates. Here’s how carbohydrates are used:

  • Carbohydrates are converted to glucose, which is the body and brain’s main source of fuel.
  • Carbohydrates are stored in the muscle and liver in the form of glycogen to be used during vigorous bouts of physical activity.
  • All of the tissues and cells in our body can use glucose for energy.
  • Carbohydrates are needed for the central nervous system, the kidneys, the brain, the muscles (including the heart) to function properly.
  • Carbohydrates are anabolic and play a role in the regulation of insulin
  • Carbohydrate-dense foods vary drastically in their glycemic index (GI), which is a number associated with a particular type of food that indicates the food’s effect on a person’s blood glucose.
  • Carbohydrates are mainly found in starchy foods (like grain and potatoes), fruits, milk, and yogurt. Other foods like vegetables, beans, nuts, seeds and cottage cheese contain carbohydrates, but in lesser amounts.
  • Fiber is an additional non-digestible carbohydrate that is essential for decreasing the risk of obesity, heart disease, and certain cancers while maintaining a healthy gastrointestinal tract and cholesterol levels.


According to the Dietary Reference Intakes published by the USDA, 10% – 35% of calories should come from protein. The needs of protein are highly dependent on an individual’s current lean mass, physical activity levels, and goals. Most Americans get plenty of protein and easily meet this need by consuming a balanced diet, but athletes, bodybuilders and heavily active individuals will need more protein to ensure they have a positive nitrogen balance and can repair damaged tissues. Protein requirements and functions are as follows:

  • Sedentary individuals should consume 0.6 grams per pound of lean body mass per day.
  • The upper limits for protein intake for athletes and those who desire increased lean muscle mass is 1.0 gram per pound of lean body mass.
  • Growth (especially important for children, teens, athletes and pregnant women)
  • Tissue repair
  • Immune function
  • Making essential hormones and enzymes
  • Energy when carbohydrate is not available through the process of gluconeogenesis
  • Preserving lean muscle mass
  • Protein is found in meats, poultry, fish, meat substitutes, cheese, milk, nuts, legumes, and in smaller quantities in starchy foods and vegetables.


Contrary to some individuals beliefs, fats do not directly impact the amount of subcutaneous or visceral fat that one stores. Fats do have the highest amount of calories per gram, therefore high fat diets can be attributed to caloric overconsumption, which leads to weight gain and increased risk for metabolic disease.  That being said, fat consumption is essential for survival. According to the Dietary Reference Intakes published by the USDA 20% – 35% of calories should come from fat. Fat is used for:

  • Normal growth, development, and hormone regulation
  • Energy (fat is the most concentrated source of energy)
  • Absorption of fat-soluble vitamins ( like vitamins A, D, E, K, and carotenoids)
  • Providing cushioning for the organs, and regulation of reproduction system
  • Maintaining cell membranes

Whether you want to get lean or increase muscle mass, if you want to achieve your fitness and health goals as rapidly and scientifically as possible you will calculate your macronutrient needs based on your individual goals and attributes then start tracking them by measuring your foods. It is also helpful to use apps such as MyFitnessPal to log, manage and track your nutrition.


[1] https://www.cnpp.usda.gov/dietaryguidelines
[2] https://www.choosemyplate.gov/
[3] https://www.ncbi.nlm.nih.gov/pubmed/15107010

About the Author

, Celebrity Personal Trainer and Fitness & Nutrition Expert headquartered in Scottsdale, AZ. He specializes in helping men and women achieve weight loss, muscle building, toning and other customized fitness & nutrition programs to create a Healthy Lifestyle. James offers private luxury personal training, 12-week custom workout plans, and personalized nutrition meal plans. Follow on Google+.

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