#IIFYM: A Focus on Macronutrients

IIFYM isn’t just a hashtag, it’s a way of life. Tracking your macros could be the game-changer for your fit lifestyle.

If you hang out at the gym, you’ve probably overheard someone talking about IIFYM, the popular acronym for “If It Fits Your Macros.” Also known as flexible dieting, IIFYM is a diet that has proven benefits, particularly for those wanting to feel more toned and lean. The IIFYM lifestyle is a variation on calorie counting, but rather macronutrient counting, or macros.

A macronutrient is a type of food that falls into one of three categories: fat, carbohydrate or protein. Depending on your age, gender, weight and activity level, there is a designated number of grams of fat, carbohydrates and protein that is appropriate for you to either gain weight, maintain weight or lose weight.

While it can work well, it still depends on making good food choices. If you choose to fill your macronutrient allowance with processed foods like pizza or ice cream, you will not feel good doing this diet. For example, 20 grams of processed fat from potato chips versus 20 grams of healthy fat from avocado will have significantly different impacts on the body. The key, much like any diet, is to be eating clean, whole foods.

Three Main Macronutrients


Fat is the macronutrient that provides the highest amount of calories per gram eaten. For every gram of fat, your body gets nine calories. While this may seem like the macro you would want to avoid, fat is critical for proper cell and hormone health, as every single cell membrane in your body is made up of fat. Fat is also what leaves you feeling satisfied after a meal. Good sources of fat include fish, olive oil, coconut, nuts, seeds and avocados.


A carbohydrate is the macronutrient that provides you with quick energy. For every gram of carbohydrate you consume, your body gets four calories. Unless it’s during or right after a workout, you want to have complex carbohydrates that are slow to digest and high in fiber. These will keep you full longer and help reduce cravings. Good examples include yams, quinoa, brown rice, fruit and vegetables.


Protein is the macronutrient that is essential for muscle health and for balancing blood sugar. For every gram of protein, your body gets four calories. From a nutrition standpoint, you want to ensure every meal contains some protein, preferably a minimum of 20 grams. Good sources of protein include meat, fish, eggs, protein powders and organic soy (in small amounts).

How to Calculate Your Macros

IIFYM.com has a very simple online macro calculator where you input your goal, gender, age, height, weight and information regarding your activity level and it will calculate your optimal number of calories and grams of each macronutrient.

Here’s an example of how you’d calculate needed macronutrients for a 25-year-old female, weighing 59kg, measuring 162cm in height, who exercises three times per week.

Step 1: Calculate her Resting Energy Expenditure (REE).

10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161 = REE
(10 x 59kg) + (6.25 * x 162cm) – (5 x 25) – 161 = 1317 calories

Step 2: Given she does moderate activity, three times a week, we’ll multiply the REE by a factor of 1.55 to get her Total Daily Energy Expenditure (TDEE).

TDEE = 1317 x 1.55 = 2041 calories

To maintain her weight, she would need 2,041 calories each day. To gain weight, she would need to consume more than 2,041 calories daily; and to lose weight, she would have to eat less. Assuming she is working to lose a little bit of weight, we’ll take off 10 percent of her daily calories, ending at 1,837 calories.

Step 3: To take this a step further to calculate her macros, she would do the following calculation:

Protein: 1.8g /protein per kg of weight = 104g protein
There are four calories per gram of protein, which gives you 416 calories from protein.

Fat: 25 percent of calories should come from fat. And there are nine calories per gram of fat.
1837 x 0.25 = 459 calories from fat
459 / 9 = 51g fat

Carbohydrate: The remainder comes from carbohydrates. There are four calories per gram of carbohydrate.

1837 – 416 – 459 = 962 calories from carbohydrates.
962 / 4 = 240g carbohydrates

Total: She would consume 104g protein, 51g fat and 240g carbohydrates for a total of 1,837 calories daily to lose weight.

How To Track Your Macros

If you’re eating a food that has a nutrition label on it, look at the grams under each category. Make sure you’re taking into account the serving size. For example, many packaged foods will have the nutrition information for one-third or half of what’s in the package.

For items that do not have a nutrition label on it, such as fresh produce for example, a quick Google search will tell you the nutrition information per measurement of food. Those that are looking to do this properly should invest in a food scale because simply eyeballing the size of food can leave significant room for error.

Why It’s Important

Tracking your macros is important (and actually works) because people tend to underestimate or forget what they’ve eaten in previous meals.

Tracking food intake is proven to double weight loss, according to a study by Kaiser Permanente’s Center for Health Research.

Who’s Doing It

The IIFYM diet has been popularized by bodybuilders and fitness models, and most recently has gained more exposure with the #IIFYM hashtag on social media.

Whether IIFYM is for you, understanding exactly what and how much you’re putting into your body is essential to meet your fitness goals.