The Lowdown on Popular Diets: Macros Edition

Counting macronutrients (or “macros”) has been a popular dieting tactic in bodybuilding groups for years. However, recently the amped-up version of calorie counting has gone mainstream — touted primarily as a tool to change body composition, though some believe it can be an athletic performance enhancer. 

What is counting macros?
Counting macronutrients, sometimes referred to as “flexible dieting” or “If It Fits Your Macros” (#IIFYM), is a regimented form of tracking what you eat that focuses on counting grams of the three macronutrients that provide calories: protein, carbohydrates, and fat. Each person’s macronutrient breakdown and calorie goal will depend on the individual’s goals as well as height, weight, age, gender, and activity level. For example, endurance athletes might emphasize carbohydrates more than protein and fat whereas bodybuilders focus more on protein and limit carbohydrates. There are free online macro calculators to determine your ratio, but it’s recommended that you work with a registered dietitian who specializes in counting macros to help you determine the best ratio for you. 

What can you eat?
Technically there is no food that is off limits — hence the term flexible dieting used to describe this program. However, to meet your macronutrient breakdown, most people will need to emphasize whole foods over processed foods and limit added sugars and typical snack foods. 

What’s off limits?
As long as you balance your macros and meet your daily goals, technically no one food is off limits. 

Anything else I should consider?
This program works well for those that like numbers and don’t mind tracking everything they eat. Many people like the flexible nature in that you can still enjoy your favorite foods as long as it fits within your macro guidelines. And many people find their food choices naturally improve towards healthier options in order to meet their ratios.  However, because it requires strict food tracking and access to information including protein, carbohydrate, and fat grams, many find it tedious and not a great long-term solution. Successful macro counters cook most meals at home and pay strict attention when eating out at restaurants. 

And for some, planning and tracking every macronutrient may lead to an unhealthy obsession with food or a diet that is too regimented, ultimately leading to a disordered eating pattern. It’s highly recommended that anyone with a history of disordered eating avoid this program as the attention to detail and strict tracking can be a trigger for eating disorders. 

If you want to know the science…
There is little research on counting macros beyond studies that have tested the benefit of limiting or emphasizing one specific macronutrient (such as high fat or low fat diets). However, the evidence does suggest that when paired with exercise, counting macronutrients can lead to weight loss. The research does not tell us if it works better than just counting calories or focusing on eating balanced meals that emphasize whole foods. 

One study among bodybuilders found no difference in macronutrient intake between male strict dieters and male macro counters; however, females ate significantly more of all macronutrients when following the macro counting plan instead of the strict diet plan. Performance and body composition was not measured, so it’s unclear if eating more was beneficial. 

If you’re interested in counting macros, consider reaching out to a registered dietitian to help you find the most effective plan for you. 

Disclaimer: The information in this article is not intended to be medical advice and if you are considering starting a new diet, work with your healthcare team to find the best approach for you.

Read about other popular diets in this series:


The Ketogenic Diet

Whole 30

Intermittent Fasting


The Paleo Diet