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Home » OSL Blog » What is If It Fits Your Macros (IIFYM)? Ultimate Diet Guide

What is If It Fits Your Macros (IIFYM)? Ultimate Diet Guide

June 26, 2019

Have you heard of the diet craze IIFYM? The acronym stands for If It Fits Your Macros, and yes, it’s a thing. A wildly successful thing, some would say.

This specific diet has been around for a long time and was used even in the Golden Era of bodybuilding. It may not have been called IIFYM, but eating a balance of macronutrients was the key to gaining massive muscles.

Ric Drasin

But what is IIFYM, and how is it different from every other diet out there? We’ve covered a few here at OSL, including the Keto Diet, Caveman Diet, and the military diet.

Today we’re going to discuss the good and the bad of the IIFYM diet. Once we’re done, you should be able to determine if it’s the right fit for you.

IIFYM Diet Plan

The entire diet is based on macronutrients. Call it a macro diet for short, if you want. The theory is that as long as you stay within your own personal macronutrients, you’ll lose weight.

Sound crazy, or too good to be true? Well then, keep reading.

Macronutrients are:

  • Protein
  • Carbohydrates
  • Fat
wholesome foods
Wholesome sources of protein, carbohydrates, and fat.

To determine your ratios for each, you can calculate them out yourself or use a macro calculator. You can also use an app like MyFitnessPal that has a section specifically for macronutrients.

Once you’ve calculated your macros, you’re ready to start. Now, IIFYM is called a diet plan, but it’s unlike any other diet you’ve tried before.

Eat Whatever You Want

How are we so sure of this? The reason for its popularity is that you can eat anything you want on the IIFYM diet. Yes, ANYTHING. 

Pick whatever food you want for your meals. Of course, there will be a learning curve with any new diet plan or way of eating. But, once you start you’ll get the hang of it.

Healthy and junk food
On IIFYM, different foods can be consumed as long as they fit your macros.

A lot of people use an app to input their food so they can keep track easier. If that doesn’t work for you, keep a food diary or spreadsheet. As long as you are able to calculate the macronutrients of all your food.

If you stay within the calculated macros, then you’ll lose weight. It’s really that simple, and that’s why it’s so popular among people who have tried other diets and failed.

Equipment needed

You mean I need to buy equipment to start this diet? You don’t have to, but it will make your life easier.

First, start with a free app to track your macros. We mentioned MyFitnessPal above, but there are others out there as well.

food scale
To start will, for IIFYM, a food scale and a tracking app are needed.

You might also want to consider getting a food scale and a body scale. The food scale will help you to weigh your food. This is important so that you can enter the right numbers in your food tracker. Guessing really doesn’t work, and if you throw off your macros, you won’t lose weight.

The body scale is for you to track your Body Mass Index (BMI) and body fat percentage. The easiest way to do this is to buy a digital scale that does all the work for you. Just stand on it and then record the numbers in the same app you are tracking your food.

body scale
Both a normal scale & a digital one will help you calculate your BMI & track results.

The great thing about using these tools is that you are able to keep track of everything in one place. That way, you can go back and see your changes over time. 

When you track your food, it makes it a lot easier to go back and review. You can start to learn the different amounts of macros are in the foods that you eat most often. After a while, the entire process takes less time and all the tracking becomes part of your routine.

hidden sugar
Tracking will result in avoiding hidden calories such as grams of sugar in “healthy” drinks.

Also, calorie creep (or calorie sneak) is a real thing. It’s the reason a lot of people can’t lose weight and they don’t even realize it. Tracking and weighing your food is a great way to avoid calorie sneak so you can actually meet your goals.

How to Calculate Your Macros

We aren’t going into detail on calculating your macros in this article. We wrote an entire article already devoted to it, so go here if you want to calculate them yourself.

It’s also a good idea to check your calculations before you get started. So go ahead and use a free app or the IIFYM macros calculator on their website to check your work.

Calculating your caloric needs and macronutrient distribution are IIFYM essentials.

One thing we do want to stress is that, as you lose weight, you’ll have to redo your calculations.

Essential Criteria

There are few criteria that are needed in order to calculate your macros:

  • Age
  • Gender
  • Activity level
  • Height
  • Weight

Since weight is a factor, then you’ll have to adjust as you lose. A good problem to have, right?

Also, since activity level is a factor as well, you’ll want to adjust it as your activity increases. We suspect that as you lose weight, your activity level will naturally increase as well. 

Working out
Adjusting your activity levels requires adjusting your calorie intake as well.

Depending on how much weight you have to lose, you might find yourself recalculating often in the beginning. If this is the case, you might want to use an app for ease.

What Should I Eat?

ANYTHING YOU WANT! Seriously though, we understand that not many people actually know the macros that makeup what they eat. And until you start to become familiar, it might feel a little overwhelming.

You will probably be eating a higher amount of protein than carbs and fat. To help you out, we’ve included some foods here that are high in each of the macros to get you started.

protein foods
Meat, poultry, & fish are among high protein foods.

1. Foods High in Protein

  • Eggs
  • Chicken breast
  • Pistachios
  • Almonds
  • Oats
  • Lean beef
  • Cottage cheese
  • Milk
  • Broccoli
  • Tuna
  • Lentils
  • Whey protein
  • Quinoa
  • Pumpkin seeds
  • Turkey breast
  • Fish
  • Shrimp
  • Ezekiel bread
  • Brussels sprouts

2. Foods High in Fat

Now, we’ve already talked before about the different kinds of fat and what’s best to eat. So this list is going to include the good fats you can consider.

high fat foods
Nuts, eggs, & avocados qualify for high fat foods.
  • Avocados
  • Pistachios
  • Walnuts
  • Nut and seed butters
  • Flaxseed
  • Olives
  • Olive oil
  • Tuna
  • Salmon
  • Tofu
  • Dark chocolate
  • Sunflower seeds
  • Chia seeds
  • Edamame (soybeans)
  • Eggs
  • Avocado oil

3. Foods High in Carbohydrates

high carb foods
Bread, fruits, & legumes are foods high in carbohydrates.
  • Sweet potatoes
  • Chickpeas (garbanzo beans)
  • Bananas
  • Apples
  • Quinoa
  • Oats
  • Kidney beans
  • Raisins
  • Beets
  • Blueberries
  • Grapefruit
  • Oranges 
  • Lentils

We definitely said that on the IIFYM diet plan you can eat whatever you want. And, we mean it. But that really doesn’t mean that you should constantly fill up on junk and empty calories.

What Good Eating Helps Avoid

Especially if you are going to be working out while you are eating this way. You want to fuel your body properly to avoid

  • Burn out
  • Dizziness
  • Fatigue
  • Fainting
  • Nausea
  • Throwing up
  • Feeling like overall crap
fatigued bodybuilder
Fueling your body with junk food will result in fatigue, burn out, and much more.

Feel free to enjoy your bread, pasta, and cereals. Sure, have some ice cream or a donut for breakfast some days. It fits in the plan and as long as you stay within your macros for the day, you’re golden. But make an effort to eat these types of foods only in moderation so you can actually see and feel the results you’re working toward.

The Benefits of IIFYM

Besides the fact that you can eat whatever you want, there are other benefits to eating IIFYM.

1. No Need to Plan Ahead

A lot of diets require restrictions, some more than others. Limitations can quickly derail even your best efforts when trying to lose weight. 

food socializing
You can enjoy the social aspect of food without restrictions on IIFYM.

Missing out on social time with friends or having to take a meal with you while others indulge is no fun. With IIFYM, this won’t happen. The most you might have to do to plan ahead is check out the menu beforehand to make sure you won’t go over your macros. 

That’s it. And for some, that’s why it’s so successful.

2. All is Good in Moderation

Dieting is really difficult for some people. We’ve been taught there are good and bad foods, and the bad foods are the hardest to resist. With IIFYM, you can undo all your prejudice against food and really start to live. 

Of course, don’t go overboard and just eat a ton of junk food, even if it fits in your macros. Your body will feel like crap and you won’t make the progress you’re looking to gain. Or lose, depending on how you look at it.

3. No Cheat Days Needed

With IIFYM, every day can be cheat day if you want it to be. Ready for ice cream at the end of the day? Fit it into your macros for the day and have at it. Want to gorge on a delicious pizza with your bestie? Just go lighter with your other meals and go for it! 

cheat day
No cheat days are needed, and restrictions are no more on IIFYM.

IIFYM not only removes the cheat day being dangled in your face, but it can also help eliminate bad habits. No more binging if restricting was part of your prior diet. A healthier relationship with food. The ability to have a treat when you want, as long as it fits in with the rest of your day.

Of course, all these benefits are awesome. But you still should check with a doctor before you start, especially if you’ve had food relationship issues before.

Proceed with caution. Then, when given the green light, full steam ahead!

The Risks of IIFYM

With any type of diet plan, there are at least some risks involved. The IIFYM diet plan is no different.

Here are some things to consider if you are weighing whether IIFYM is right for you.

1. The Only Focus is Macronutrients

One of the things that IIFYM does not consider is micronutrients. Vitamins and minerals are needed micronutrients that are crucial to overall health. 

Micronutrients are acquired from food & they are necessary for healthy bodies.

If you focus solely on macros in your diet and forget micros, you could become vitamin or mineral deficient. Our bodies are unable to produce micronutrients on their own, so they need help from our diets.

The most common deficiencies are:

  • Iron
  • Vitamin A
  • Vitamin D
  • Folate
  • Zinc
  • Iodine
sick male
Deficiencies will result in health issues like anemia and fatigue.

Keep this in mind, regardless of if you decide to use IIFYM or not. Here are some of the issues you can face if you are deficient in these micronutrients.

  • Anemia
  • Mental impairment
  • Poor immune system
  • Eyesight impairment
  • Growth hormone issues
  • Birth defects in pregnant women who are deficient

2. No Flexibility for Illness and Recovery

The IIFYM diet plan may not be rigid in food choices, but it is when it comes to illness or injury. There is no flexibility that allows for increases in calories or protein to help rebuild muscle mass

Healing an injury requires increase in calories which is not possible on IIFYM diet.

It also doesn’t account for these increases to speed up recovery. Women who breastfeed after giving birth need a higher amount of calories to replace what is depleted by the baby. 

And people who have had ICU stays that last longer than a few days usually leave with less body mass. Once they leave, they have to play catch up with their calorie intake and exercise. This is just to get them back to where they were before they were admitted.

ICU patient
Patients who leave ICUs need to increase calories after to regain lost weight.

This study calls for a systemic need for macronutrient goals for ICU patients, especially those who are obese. The current food trends reduce lean muscle mass and healing in recovery. A healthier and more focused food plan could actually reduce ICU stays and increase health in patients. Right at the time where they need it the most.

These are all considerations that should be made by the individual but are not part of IIFYM. Something to consider with this way of eating and how it fits into your life and goals.

Common Misconceptions

As with any diet, there are always going to be misconceptions or untruths surrounding it. Let’s dispel some of them here.

1. You Can Only Eat Clean, No Junk Food

We kind of touched on this already in this article. But, the great thing about IIFYM is your freedom with food. 

You can eat whatever you want, in moderation, and still experience weight loss. Of course, we want to see you eat healthy foods that fuel your body effectively. But we’re also human just like you and indulge in unhealthy foods from time to time.

You only live once, and to deprive yourself of some things just isn’t worth it. As long as you keep yourself in check with junk food. 

IIFYM will help you hit milestones and food will be your everyday reward.

If you find that difficult, then maybe you should try to use junk food as a milestone reward. Here are some ideas:

  • Track your food effectively for 15 days in a row
  • Hit the gym at least three times a week for three weeks straight
  • Stay within your macros with mostly healthy food for two weeks straight
junk food
To decrease junk food intake on IIFYM, reward yourself with it once goals are achieved.

Once you hit each goal, reward yourself with a dessert size portion of your favorite junk food. As you gain confidence within the program, hopefully, you’ll also improve your relationship with food.

2. Is IIFYM Really A Diet?

Actually, no, it’s not. IIFYM was created not so much as a diet, but a way of eating. Most people not only have to change their relationship with food but also their lifestyle.

Most will continue to use IIFYM well after they hit their weight loss goal. If not, then going back to old habits will likely cause weight gain in those who do. 

no diet
IIFYM isn’t a diet as it allows flexible eating and supports a healthy relationship with food.

But for many, once they’ve reached their goal, they realize how great their body feels. They can be more active, get tired less easy, and have more energy. So they then go into maintenance mode.

Satisfaction is definite once you achieve your fitness and weight-loss goals on IIFYM.

Some people won’t have to continue to track their macros forever, and some will. No way is right or wrong.

3. It Takes Too Much Time

Actually, unlike many diet plans, IIFYM takes less time than most. Yes, you may have to weigh foods and take the time to enter information into your app of choice. But you won’t have to

  • Meal plan – unless you want to
  • Meal prep – again, unless you want to
  • Prepare a meal to go out because the menu doesn’t fit your plan
  • Plan your day around your food choices and meal times
meal plan
Meal plans and preps are not necessary on IIFYM unless they are preferred.

There is a bit of a learning curve in the beginning, and you’ll likely put in the extra effort then. But once you get the hang of IIFYM and keeping a food diary, it becomes part of your routine.

And for most, it’s worth the extra time. If you have weight loss goals and have struggled to meet them, IIFYM might just be the plan for you.

4. It’s Only for Fitness Buffs

It’s true, the plan is very popular with weightlifters and bodybuilders. Paying attention to your macros and eating to fuel your body along with a fitness plan makes sense.

medium sized bodybuilder
IIFYM is for everyone from professional athletes to beginners.

But the beauty of IIFYM is that it’s for anyone and everyone who wants to see real results. Whether you’re a lifter, fitness-obsessed or just want to look good in a swimsuit, IIFYM can work for you.

5. Junk Food Rules, All Day Every Day

We’ve mentioned this a few times, but some people think IIFYM gives you free rein to eat junk all day. While you certainly can if you choose, it won’t give you the results you are looking for.

balanced meals
You can enjoy all foods on IIFYM as long as you hit your macros.

IIFYM is unique in that you can eat whatever foods you want, as long as it fits within your macros. But you can’t out-exercise an unhealthy diet. And if you’ve read any of our nutrition articles, you’ll know we advocate for healthy most of the time.

It just makes sense to fuel your body with nourishing food to help you meet your fitness goals. Muscles aren’t built on sugar and processed foods. Energy isn’t created by food with no nutritional value. 

Nourishing & healthy foods will help you build muscles more efficiently.

Sure, keep some of your favorite unhealthy foods and have them – in moderation. Deprivation is a sure way to derail even the best efforts on a diet. That’s why so many fail at other diet plans that are more rigid than IIFYM.

Here is a great article from the National Heart, Lung, and Blood Institute (NHLBI) that discusses energy balance. It describes how to balance eating to lose or gain weight as well as incorporate balance with different foods.

IIFYM Reviews

As with any diet plans, there are lots of reviews out there. We won’t link to them, but you can find a lot of people who have had real results. And of course, you will find some negative reviews as well.

IIFYM will help you achieve weight-loss goals.

What we will provide here is food for thought. We’ve said it a few times but to be truly successful with this diet plan, you have to eat well. At least 85 percent of your diet has to be healthy foods with a little bit of unhealthy mixed in if you must.

What Studies Say

Consider this study of twenty people who ate either a high-energy or low-energy density diet. Of the people who ate low-energy foods, they were able to consume about half the calories of the others. They felt satisfied on roughly 1,570 calories/day rather than the 3,000 calories the other group was consuming.

Calorie counting is the efficient path to weight-loss.

These studies further agree that energy density in foods plays a role in cognitive and behavioral cues related to food. Eating a diet of mainly low-energy density foods satisfy you longer and help create healthier eating patterns.

Low-energy density foods yield longer satisfaction.

So, what do you think? Does it sound like IIFYM is for you, or do you think it’s just another fad diet?

Do you eat this way, or have you tried IIFYM? Do you think it’s a good diet plan? Let us know why or why not in the comments.

Disclaimer: None of the individuals and/or companies mentioned necessarily endorse Old School Labs or COSIDLA Inc. products or the contents of this article. Any programs provided for illustration purposes only. Always consult with your personal trainer, nutritionist and physician before changing or starting any new exercise, nutrition, or supplementation program.
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