What is IIFYM?
IIFYM is a method, or style, of dieting used to improve body composition by tracking your macronutrients (macros). IIFYM stands for “If It Fits Your Macros.”
IIFYM allows people to lose or gain weight without having to eat clean 100% of the time, and sustain that weight loss enjoyably.
This article will show you why and how to get started with a macros calculator.
Table of Contents
There are three main macronutrients that are traditionally accounted for:
- Protein (4 calories per gram)
- Carbs (4 calories per gram)
- Fats (9 calories per gram)
By tracking these macros on our fitness goal pursuit, you’ll naturally be tracking your calories as well.
Weight loss ONLY occurs when you are in a calorie deficit. It’s science..
IIFYM follows universal laws (the Law of Energy Balance) that have been proven time and time again and cannot be ignored in terms of fat loss.
There is no manipulating these laws to your benefit. The best you can do is follow them to achieve your desired outcome.
And that’s what IIFYM accomplishes if followed correctly.
If you’ve done any research on IIFYM in the past, perhaps you’ve realized that no foods are off-limits and that no food groups are labeled as good or bad for you.
Instead, what matters in this style of dieting is if your daily macro budget has room for the foods you want to eat.
If so, then you’re in the clear; more on this soon.
Why is IIFYM Superior to Most Weight-Loss Diets?
Are you really going to try to lose weight by sticking to “clean” foods?
Are you really never going to eat ice cream, pizza, or a burger, again?
So your meal plans are just going to include eating broccoli, chicken, and brown rice for the rest of your life, right?
The approach to most weight-loss diets consists of eating 5-7 small meals throughout the day to promote weight loss.
Well, this approach just leads to all-out binge days or late-night cravings.
Not only that but what happens when (or if) you lose the weight?
You’ll just go back to how you normally ate and gain all or most of the weight back.
It’s a LOSE-LOSE situation.
To back up this claim further, a study found that when it comes to diets, people who try sticking to super strict diets were more prone to eating disorders, they carried more body fat, and they were also generally more depressed and miserable! 
IIFYM is different, and superior, in my opinion, and millions of other IIFYMers agree with me.
Contrary to popular belief, IIFYM is NOT about eating Pop-Tarts for breakfast every day.
Unlike traditional diets, you have the option to eat:
- What you want
- When you want
If you make it fit into your daily macro budget.
While the option to eat junk food (pizza, burgers, ice cream, cookies, etc.) exists, you certainly don’t have to partake in it.
This is why Flexible Dieting and IIFYM have never been synonymous, in my opinion. Most flexible dieters think badly about IIFYM because they think all we eat are ice cream and pizza.
In fact, the opposite is true.
The edge that IIFYM dieting has over traditional dieting is its flexibility (pun intended). That being said, I will use flexible dieting and iifym interchangeably.
This flexibility offers you the ability to improve your body composition without having to be perfect with your diet.
You can utilize IIFYM for weight loss, maintaining your current body weight, or even building muscle.
It just requires a couple of simple steps to follow every day.
How Do I Start IIFYM?
There are many easy ways to start.
You can use our IIFYM calculator (down below), or do it by hand (which I recommend for beginners).
I’ll show you how to do it by hand after so you get a better understanding of how everything works.
Can you lose weight on IIFYM?
Yes, of course. You can use IIFYM for weight loss, weight gain, or year-round maintenance.
For our example, I’ll show you how to calculate your daily calorie consumption (for weight loss) by calculating your energy expenditure first, based on your activity level.
That was a mouthful… It’ll all make sense in a second.
Use this free IIFYM Calculator below:
Now that you’ve seen the calculator, let’s go over it by hand to give you a better understanding.
Step 1: Find your Total Daily Energy Expenditure (TDEE).
To do this, figure out how active you are on a daily basis. Are you:
- Sedentary (little to no exercise)
- Mostly-Sedentary (Office work + Lifting 3-5 days a week)
- Active (4-6 hours of exercise/sports per week or equivalent)
- Very Active (7-9 hours of exercise/sports per week or equivalent)
Once you figure that out, use these activity level multipliers for the formula below:
- Sedentary = 14
- Mostly-Sedentary = 14.5
- Active = 15.5
- Very Active = 16.5
The formula is:
Your body weight in lbs x your activity level multiplier
For example, my current body weight in lbs is 200.
I also fall into the “Mostly-Sedentary” level so my rough estimate of my TDEE would be 200 x 14.5 = 2900 calories.
2900 calories are NOT my diet calories.
They are the number of calories I would eat to maintain my current weight of 200 pounds.
Once you’ve found yours, move onto the next step.
Step 2: Find Your Diet Calories (AKA. Your Calorie Deficit)
Now, you’re going to take the number above from Step 1 and multiply it by 0.75.
For example, 2900 calories (calculated above) x 0.75 = 2175 calories to lose weight.
This will give you a 25% calorie deficit which allows for 1-2lbs of weight loss per week.
Remember, the universal law of energy balance must be accounted for.
If you are not in a calorie deficit you will NOT lose weight.
I don’t care what macro calculator you use, or if you’re vegan, follow keto or paleo, it will not work.
Once you’ve found your calorie deficit, it’s time to utilize iifym and turn them into macros.
Step 3: Find Out How Many Macros You Need and How to Start Tracking Macros
Now that you have your calories, you have to turn them into macros. To do this, we turn them into grams, because macros have their own calorie per gram make-up.
If you remember from above, there are:
- Protein (4 calories per gram)
- Carbs (4 calories per gram)
- Fats (9 calories per gram)
Before that, however, we must figure out your preferred macro split.
How Many Macros Should I Eat a Day?
What are the best macros for cutting?
The most popular ones I’ve seen work for most people are:
- 40% Protein /40% Carbs /20% Fat
- 50% Protein /30% Carbs /20% Fat
- 30% Protein /50% Carbs /20% Fat
Something you may notice is that Fat is constant here at 20%.
I’ve found that most people either enjoy more protein or more carbs as opposed to more fat.
On top of that, fat is more than 2x calorically dense than protein and carbs (9 cal per gram vs 4 cal per gram). This is why Fat is always kept on the lower end.
Choose whichever your preference is.
For example, if you like eating lots of protein every day (chicken, beef, steak, turkey, eggs, etc.), choose the 2nd option.
If you like eating lots of carbs (bread, pasta, rice, etc.) choose the 3rd option.
If you like a more balanced approach, choose the first option, which is called the 40/40/20 macro split, and is very popular.
For this example, we’ll go with a 40/40/20 macro split approach.
To do this, take your calories from Step 2 and do the following:
- 2175 x 0.40 = 870 calories from protein
- 2175 x 0.40 = 870 calories from carbs
- 2175 x 0.20 = 435 calories from fat
Now that we have these calories from each macronutrient, we divide them by their own “calorie per gram” make-up.
- 870 calories from protein / 4 = 218 grams of protein
- 870 calories from carbs / 4 = 218 grams of carbs
- 435 calories from fat / 9 = 48 grams of fat.
What do you do with these macros?
Now you follow if it fits your macros.
You eat every day, whatever you want, so long as it FITS YOUR MACROS which we just calculated above.
Well, how do you do that?
Move on to step 4.
Step 4: Find Your Diet Meal Plans Macros’
This is where the fun begins.
You now have your calories and macros for fat loss, but now you don’t know what to do.
I could end this iifym guide here, however, what about meals?
How many meals and what should they consist of?
Well, that depends on your preferences.
You could have
- 2 meals
- 3 meals
- 4 meals
- 8 meals…
It doesn’t really matter, however, for myself and many others, I’ve found that 3-4 meals a day works best.
That being said, IIFYM allows you the freedom to add in foods wherever you want.
However, you always want a plan. A structure to it all.
So that’s what we’re going to do now.
Let’s take the macros from step 3 and divide it into 3 meals:
- 218 grams of protein / 3 = 73g of protein per meal
- 218 grams of carbs / 3 = 73g of carbs per meal
- 48 grams of fat / 3 = 16g of fat per meal
Now that you know how many macros you should have per meal, let’s make a sample meal plan in Step 5.
Step 5: Make a Meal Plan For Your IIFYM Diet
Our macros per meal, based on 3 meals a day are:
- 73g of protein
- 73g of carbs
- 16g of fat
Let’s talk about one of these meals:
73 grams of protein can be made up of (these are estimates – your foods macros may vary):
- 12.5 oz of Chicken Breast
- 13 oz of 93% Lean Ground Beef (but also 26g of fat which can be taken out from other meals)
- 13.5 oz of Salmon (but also 17g of fat)
To make this simple, let’s go with Salmon, cause I love my salmon.
So for 1 big meal, I’d have 13.5 oz of Salmon which consists of:
- 73g of protein and
- 17g of fat.
That takes care of Protein and fat for this 1 meal.
The fat from the Salmon is enough, trust me, it’s delicious 😀
Next would be finding your 73g of carbs for your meal which can come from:
- 286g of Sweet Potatoes
- 418g of Red Potatoes
- 312g of Brown Rice
- 260g of White Rice
We’ll go with White Rice cause I love my rice.
So for MEAL 1, we have:
- 260g of White Rice (73g of Carbs)
- 13.5oz of Salmon (73g of Protein and 17g of fat).
Note: You would need a food scale to weigh this out for your macro tracking. I use this one.
After this meal, you have:
- 145g of protein left for the day
- 145g of carbs left for the day
- 31g of fat left for the day.
You can eat a similar meal again, or make it up as you go, so long as it fits your remaining macros.
Want to have a slice of pizza? Go for it. Just make sure to hit your protein requirements as pizza would take a lot from fat and carbs.
Want a Hershey’s Bar?
Cool. Just subtract it from your remaining macros.
Remember what it says IIFYM if it fits… It must FIT your macros.
That’s the beauty of IIFYM and tracking macros.
You don’t have to give up any carbs or fats or any of your favorite foods because you’re on a diet.
If you want to learn more about tracking macros and IIFYM, my new book will be of interest to you.
The Bottom Line on IIFYM: If It Fits Your Macros
IIFYM offers anyone the opportunity to tailor their diet to include their favorite nutritious foods while mixing their favorite treats every day– and still making progress towards their fitness goals.