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What Are Macros?

Macronutrients, or macros for short, are the three key nutrients that our bodies need in large quantities and are responsible for providing energy to the body. These three macronutrients are carbohydrates, fat, and protein and they make up the calorie content of the food we intake. Any food, beverage, or supplement that contains calories is made up of carbs, fats, proteins, or, most often, a combination of these. Every 1 gram of carbohydrate yields 4 calories, 1 gram of protein yields 4 calories, and 1 gram of fat yields 9 calories.

Tracking Macros

Tracking macros, also known as IIFYM (If It Fits Your Macros) or Flexible Dieting, is essentially a more detailed way of tracking calories. It is commonly used among bodybuilders, powerlifters, and other athletes as a tool to maintain or alter body composition or weight. The idea is that as long as a certain food fits within your allotted daily macros, you can have it. There are no forbidden foods or food groups, and you can still incorporate all your favorite foods. However, a diet consisting mostly of foods high in protein and fiber (think lean meat, fruits, vegetables, whole grains, etc.) will likely be more satiating than a diet built off highly processed foods. Indulgent foods can (and should) still be enjoyed, but are best consumed in moderation to prevent hunger pangs, hitting macro goals too early in the day, and feeling restricted.

Understanding Each Macronutrient, Their Roles in the Body, and How Much Of Each Is Needed

Each macronutrient plays it’s own specific role in the body, which is why each is necessary in the diet.

Proteins

Proteins are found in virtually every tissue in the body including muscle, skin, hair, and bone. Proteins are responsible for building and repairing tissue (muscle protein synthesis), protecting the body from bacteria and viruses by acting as antibodies, functioning as enzymes, and are responsible for transporting molecules throughout the body. Proteins are made up of 20 different amino acids. Of these 20, the human body can only synthesize 11 on its own, these are known as non-essential amino acids. The remaining 9, known as essential amino acids, must be obtained through food. However, not all dietary sources of protein are created equal. Proteins that come from animal products such as meat, poultry, dairy, and eggs, as well as soy which is plant-based, are complete proteins, meaning they contain all 9 essential amino acids. Aside from soy, most other plant-based sources of protein are not complete proteins, meaning they are missing 1 or more of the 9 essential amino acids. For those on plant-based diets, it is important to consume a wide variety of plant-based protein sources to ensure all 9 essential amino acids are being consumed throughout the day. Complementary proteins can be formed by pairing 2 or more incomplete protein sources to make up all 9 essential amino acids.

The RDA for protein in adults is 0.8g/kg of body weight, but studies have shown upwards of 1.6-2.5g/kg of bodyweight may be optimal, especially for active or resistance trained individuals. A higher protein intake is especially important for individuals eating in a caloric deficit to aid in the prevention of loss of lean mass. The protein intake recommendation for percent of total daily calories in adults is 10-35%.

Fats

Dietary fats are responsible for providing energy to the body. They are also essential for hormone production and regulation, vitamin and nutrient absorption, protecting the body’s internal organs, and insulation. However, like proteins, not all dietary fats are created equal. While all dietary fats have the same amount of calories per gram (9 kcal/g), some fats are recommended to be consumed in limited quantities.

Carbohydrates

Carbohydrates are an essential part of the diet and provide the body with it’s main source of energy, glucose. Carbohydrates also promote brain function, and the fiber found in some carbs promotes good digestive health. Carbohydrates are either simple or complex.

Simple carbohydrates are broken down more quickly and provide a quick source of energy, however, too many simple carbohydrates may cause frequent blood sugar spikes, which can negatively impact health. Complex carbohydrates break down more slowly, which means they provide energy for a longer amount of time. Complex carbohydrates are also a rich source of fiber.

For adults, the recommended percent of daily calories from carbohydrates is 40-65%. However, those with underlying health conditions such as diabetes may need to limit carbohydrate intake lower than this recommendation and should instead follow the recommendations of their doctor or dietitian.

Weight Loss, Gain, and Maintenance

Changes in weight, whether it be weight gain, weight loss, or weight maintenance, all come down to energy balance (Calories in versus Calories out). Energy Balance = energy input – energy output. Energy input comes from calories consumed (carbs, fat, and protein), and energy output is a result of the body’s “work”, or its Total Daily Energy Expenditure (TDEE).

This means that we can manipulate our energy output most by altering our daily physical activity.

Weight gain is a result of a positive energy balance (i.e. a caloric surplus),meaning more calories are being consumed than are being burned. These excess calories are then stored as body fat.

One pound of fat is equivalent to 3,500 calories, so to lose one pound, a caloric deficit of 3,500 calories must take place. This is most commonly expressed as -500 calories per day to lose 1 pound per week (-500 kcal x 7 days = -3,500 kcal). The smaller the deficit, the more time it will take for weight loss to occur, but smaller deficits are usually more sustainable long term due to lower feelings of hunger or deprivation. Also, a small to moderate deficit coupled with adequate protein intake will result in a lesser possibility of muscle loss when compared to a rigorous deficit.

For individuals participating in resistance training who are looking to increase strength and gain a substantial amount of muscle mass, a small to moderate caloric surplus and adequate protein intake is usually necessary. This is commonly referred to as “bulking”. While some body fat will also be gained during this time, if done correctly, body fat increase should be controlled and fairly minimal.

Nutrition Labels

Energy in kcal is how many calories the portion of food contains, and macronutrient and other nutrients can also be found.

Weight vs. Volume

Portioning foods by weight has proven to be far more accurate than simply measuring by volume because there is less room for discrepancies and error. While the difference in serving size by volume versus weight may not seem like a huge difference, it is important to remember that those numbers add up and could potentially hinder progress. Food scales can be found for as little as $12 on Amazon.

It is important when weighing and tracking food, that it is weighed and tracked in the same form. For example, if a food is weighed raw, make sure that the food is also tracked raw. This is because foods either gain or lose water when cooked and this will therefore affect it’s weight, but not its caloric content. For example, 100g of raw chicken breast will lose about 30% of its water weight when grilled. Raw chicken breast weighing 100g contains about 120 calories and 23g of protein and will likely weigh about 70g after being cooked, whereas 100g of grilled chicken contains about 150 calories and 31g of protein. The opposite is true for dried foods like pasta or oats, which typically gain water weight after being boiled.

Macro Tracking Apps

There are many different ways to track macros and calories throughout the day, two popular ones are MyFitnessPal (free) and Avatar Nutrition (monthly subscription). Both apps allow users to add food by scanning food barcodes, searching a food database, and creating new foods and recipes. Avatar Nutrition may be more beneficial to beginners because it calculates weekly adjustments for calories and macros based on individual results and progress. MyFitnessPal requires the user to have slightly more knowledge and adjust their macros on their own if needed. MFP will set general macros and calories for users based on goals, however, these numbers have often found to be set too low, so it is recommended that the macros and calories be adjusted manually by the user. The free version of MFP also only allows macros to be set in increments of 5% rather than by gram, so there may some discrepancies when setting individualized macros.

How To Calculate BMR, TDEE, and Macros

When calculating estimated energy expenditure, it is important to remember that these figures are just that, estimates. Without using direct calorimetry methods, it is nearly impossible to determine exact energy expenditure. However, these formulas are currently considered to be the Gold Standard when it comes to estimating energy expenditure. It is important to monitor results on a weekly to monthly basis and make adjustments to calories and macros if necessary.

Calculating BMR and TDEE

When calculating BMR, the Mifflin-St. Jeor equation has been found to be the most reliable compared to other equations and is currently the gold standard. It takes into account weight, height, age, and gender to determine estimated Basal Metabolic Rate. The calculations are as follows:

Females: (9.99 x weight in kg) + (6.25 x height in cm) – (4.92 x age) - 161

Males: (9.99 x weight in kg) + (6.25 x height in cm) – (4.92 x age) + 5

For example, a 25 year old female who is 5’ 5” and weighs 150 pounds, would have an estimated BMR of 1,429 calories.

(9.99 x 68.2) + (6.25 x 165.1) – (4.92 x 25) – 161

681.3 + 1,031.9 – 123 – 161 = 1,429.2

A 25 year old male who is also 5’5” and 150 pounds would have an estimated BMR of 1,595 calories.

(9.99 x 68.2) + (6.25 x 165.1) – (4.92 x 25) + 5

681.3 + 1,031.9 – 123 + 5 = 1,595.2

Once BMR has been determined, an activity factor can then be applied to estimate Total Daily Energy Expenditure. BMR x activity factor = TDEE

The activity factors are as follows:

*If between activity levels or are unsure which best applies, choose a number in between each activity factor. (For example, subject who exercises 3x/week and is unsure whether Light or Moderate Activity best applies, an activity factor or 1.4-1.45 may be a good place to start.)

For example, someone with a BMR calculated at 1,429 who exercises at a moderate intensity 5 days per week would have an activity factor of about 1.55. Their estimated TDEE would be 2,215 (1,429 x 1.55 = 2,214.95). This estimates daily energy expenditure and maintenance calories. Calories will need to be added or subtracted by the amount of desired change for weight gain or loss to occur (+/- 250 kcal/day = =/- .5 lb/week; +/- 500 kcal/day = +/- 1 lb/week).

Assess progress every 1-2 weeks and make changes to daily intake if necessary.

It is important to remember that the body is not meant to be in a caloric deficit forever. Diet breaks and reverse diets are important minimize metabolic adaptations. This can be achieved by bringing calories back up to maintenance level for a period of time (minimum of 2 weeks) before returning back to a deficit. If you have been in a consistent caloric deficit for 12 weeks or longer, or if you are no longer seeing results and do not wish to decrease calories further, it may be time for a diet break or even a reverse diet. It is also important to note (especially in beginners) that when resistance training in a caloric deficit, while it is not an optimal condition for muscle gain to occur, it is possible and may be reflected as weight gain or no change in weight on the scale, despite simultaneously losing fat. This is why taking measurements, progress pictures, and body fat readings (if possible) are encouraged to prevent unnecessary cuts in calories. Loss of fat mass with no weight changes is still considered progress and is a result of caloric deficit.

Calculating Macros

Calculating macros are highly individualized and can vary based on goals, satiety responses, personal preference, incidence of certain diseases, etc. The “best” macro range is one that is sustainable while still supportive of individual goals.

Protein

Protein can be calculated by body weight. Ranges for protein can be anywhere from 0.8 - 2.5 g/kg of bodyweight. This number will likely be towards the higher end of the range for active or resistance trained individuals. Protein should account for about 10-35% of total daily calories.

Fat

Fat can also be calculated by body weight and ranges between .75-1g/kg of body weight. This may be towards the lower end of the range for those in a deficit. Fat should account for 20-35% of total daily calories.

Carbohydrates:

Carbohydrates should be calculated after protein and fat ranges have been determined and can be calculated by subtracting calories from protein and fat from total daily calories. The remaining calories should then be divided by 4, resulting in grams of carbohydrates per day. Carbohydrates should account for 40-65% of total daily calories. Again, for those with certain underlying diseases such as diabetes, carbohydrates may be restricted even further if advised to do so by a health care provider or registered dietitian.

Here is an example of how to calculate BMR, TDEE, and sample macros from start to finish:

*kcal = Calories, RT = resistance training

Micronutrients

Micronutrients are nutrients such as vitamins and minerals that are needed in smaller quantities. Micronutrients do not serve as a source of energy and therefore do not contain calories. Because of this, it is not necessary to track micronutrients specifically for body composition or weight management purposes. However, micronutrients do play a role in overall health and disease prevention. Some people, especially those with underlying health conditions or at risk for chronic health conditions may need to pay closer attention to micronutrient intake. For example, those at risk or diagnosed with cardiovascular diseases such as high blood pressure, may need to monitor sodium intake. Most micronutrients that are present in a food, beverage, or supplement can also be found on the nutrition label.

References

“Appendix 7. Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations - 2015-2020 Dietary Guidelines.” 2015-2020 Dietary Guidelines, health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/appendix-7/.

Cintineo, Harry P., et al. “Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training.” Frontiers in Nutrition, vol. 5, 11 Sept. 2018, doi:10.3389/fnut.2018.00083.

“Dietary Fats.” Www.heart.org, 23 Mar. 2014, www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/dietary-fats.

Kelly, Mark P. “Resting Metabolic Rate: Best Ways to Measure It-And Raise It, Too.” ACE Fitness, www.acefitness.org/certifiednewsarticle/2882/resting-metabolic-rate-best-ways-to-measure-it-and-raise-it-too/.

“Learn the Facts about Fats.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 Feb. 2019, www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fat/art-20045550.

“Losing Weight.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 4 Feb. 2020, www.cdc.gov/healthyweight/losing_weight/index.html.

“Protein.” The Nutrition Source, 28 Oct. 2019, www.hsph.harvard.edu/nutritionsource/what-should-you-eat/protein/.

Trexler, Eric T, et al. “Metabolic Adaptation to Weight Loss: Implications for the Athlete.” Journal of the International Society of Sports Nutrition, BioMed Central, 27 Feb. 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC3943438/.

“What Are Proteins and What Do They Do? - Genetics Home Reference - NIH.” U.S. National Library of Medicine, National Institutes of Health, ghr.nlm.nih.gov/primer/howgeneswork/protein.

“What's The Function of Carbohydrates.” Healthline, www.healthline.com/health/function-of-carbohydrates.