Whether you have been keto for a while or are just starting to look into this way of eating, you have definitely bumped into the term “macros” and the concept of “finding your macros.” But why do they matter?
“Macros” is shorthand for macronutrients, and they are compounds that your body uses for growth, maintenance, and repair—e.g. everything. Macronutrients are the largest nutrients your body needs and in the highest quantities. There exist three macronutrients: carbohydrates, fats, and proteins.
Let us mentally metabolize these macronutrients to see how they each support the body’s basic daily functions as well our health goals—whether that is weight loss, physical performance, or healing of autoimmune, neurological, emotional, or other disease conditions—and what can happen if you do not get the right mix, or ratio, of these macros.
During digestion, protein is broken down into amino acids that can form new proteins, used in growth and repair, or glucose, used to generate energy molecules like ATP. Protein has important functional roles in the body that include:
- Enzymes to speed up chemical reactions in the body
- Hemoglobin to transport materials around your circulatory system
- Antibodies in the immune system
- Clotting factors to slow blood loss
- Hormones for signaling
- Facilitators of muscle contraction
- Structural elements like collagen, elastin, and keratin
- The main component of most cell structures
- Recyclers of worn-out cells
- Ketogenic amino acids offering the body clean fuel
- Glucose offering the body fuel
A lack of sufficient protein intake can result in:
- Vitamin and mineral deficiencies
- Inhibited cellular and tissue growth (new cells, new muscle fiber, bone density)
- Inhibited cellular and tissue repair (reduces immune function, slows healing, allows accumulation of junk cells)
- Inhibited acid–base balance in the tissues and blood
Too much dietary protein, on the other hand, can result in:
- Excessive conversion to and storage of glucose by process of gluconeogenesis
- No corresponding increase in bone or muscle mass
- Increased thirst and/or dehydration
Unrefined carbohydrates are broken down into glucose in a multi-step process to generate fuel for bodily processes. Carbohydrates can have important characteristics such as:
- Preferred fuel source for ATP synthesis
- Fuel source that can be utilized for all bodily processes
- Material for amino acid production
- Building block of glycogen (a stored form of energy)
When carbohydrate intake is suppressed:
- Glucose thresholds are met though gluconeogenesis in the liver
- Stored energy (glycogen and fat) is burned and converted to ketones
- Vitamin and mineral deficiencies if other dietary intake is not diversified enough
When dietary carbohydrate intake is too high, it can yield:
- Blood sugar dysregulation
- Increased insulin levels
- Decreased leptin levels
- Diminishing amounts of carbohydrates stored as glycogen in muscle tissue and liver
- Increased storage of glucose as fat in adipose cells
Fat is broken down into fatty acids that can be used to create ATP, lipids with a multitude of functions in the body, and our favorite fuel, ketones! (As an aside, we are referring to healthy, natural fats; we assume you are already avoiding trans fats, vegetable oils, and other bad fats).
Fat can function in your body in a number of ways:
- Fuel for ATP synthesis
- Components of all cell membranes
- Building blocks for hormones
- Ketone bodies providing a source of clean fuel
- Lipoproteins to provide transport of cellular materials
- Cholesterol for cell building and repair
- Carriers for the fat-soluble vitamins A, D, E, and K
- Facilitators of mineral absorption
A lack of sufficient dietary fat can result in:
- Vitamin and mineral deficiency
- Increased risk of coronary disease
- Increased risk of depression, anxiety, neurological, and autoimmune disorders
Too much dietary fat, however, can lead to:
- Increased storage as triglycerides in adipose tissue in the liver and throughout the body
1. Tortora, G., Derrickson, B. (2015). Introduction to the Human Body, 10th Edition. Hoboken, NJ: John Wiley & Sons, Inc. p. 469, 474, 477, 478.
2. Fallon, S. (2001). Nourishing Traditions. Brandywine, MD: NewTrends Publishing Inc. p. 4, 26.
3. Ballantyne, S. (2017). Paleo Principles. Las Vegas, NV: Victory Belt Publishing. p. 52.
Jen Dodd is a former magazine editor and lifelong storyteller. While she’s lived here and there, she currently makes her home in St. Pete with her husband and 2 cats. In her day job Jen plans and markets training for nonprofit professionals in the Tampa Bay area. She is also passionately pursuing her Nutritional Therapy Practitioner certification through the Nutritional Therapy Association and thrilled to help coach folks to keto success by writing articles and serving as an admin in select social media groups.