IIFYM: A Complete Overview Of "If It Fits Your Macros"

Elliot Reimers
Written By: Elliot Reimers
January 13th, 2014
Updated: October 27th, 2021
Categories: Articles Nutrition
45.3K Reads
Close up photo of avocado, cheese and nuts
Just what exactly is "if it fits your macros", and why are all the muscleheads talking about it? This article takes a deeper look at the clean versus dirty foods discussion.

As time evolves so does our knowledge of the way the human body works, and one thing that has been hotly debated lately is whether or not the “if it fits your macros (IIFYM)” movement in fitness/bodybuilding subculture is really a proper, healthy way of dieting.

I’m generally disinterested in fixating arbitrary “percentages of importance” on the particular components of one’s fitness regimen, like saying results are determined 90% by diet and 10% by exercise,  so for now let’s just settle for nutrition being a major portion of the pie.

But now that we have this big piece of pie on our plate we are faced with another conundrum—how much of this piece is “healthy/clean” and how much is “unhealthy/dirty”?  This metaphor is already way out in left field, but I’m committed to it and don’t feel like starting over so bear with me. Let’s say we have ourselves a big ol’ piece of pecan pie. Now you might be thinking, “Hey, pecans contain bounties of ‘healthy’ (read: clean) essential fatty acids so I’ll just eat that part of the pie,” but not so fast there you nut-lover as you may just be missing out on all the goodness of that pie’s “dirty” corn syrup and flour-based crust.

This schism between “clean” and “dirty” foods has led to a dichotomy in the field of nutrition, with one side believing that you must only eat certain “clean” foods and the other claiming that food selection isn’t important so long as you meet your macronutrient and calorie quotas (hence the acronym IIFYM). Naturally, this has caused a bit of turmoil between “experts” and everyday gym-goers alike.

So what exactly is this whole “IIFYM” way of dieting and why has it caused so much of an uproar lately? Moreover, how does one go about eating IIFYM-style and what finer points should they consider before doing so? Read on, as this article will seek to answer these questions and provide you with a cerebral analysis of IIFYM.

It can be tough to take a step back and view things impartially when debating topics that you are highly passionate about, so before we move on to the meat and potatoes of this IIFYM dieting overview I suggest you keep an open mind and don’t discount certain ideologies/theories simply because you have some preconceived disdain for them; stubbornness will only limit your intelligence.

A brief word on the notion of “clean” and “dirty” foods

Huge HamburgerTime and time again the debate between “clean” and “dirty” foods rears its ugly head into fitness and bodybuilding subculture, creating a schism between individuals who cling to one side or the other. This doesn’t surprise me given the idiosyncratic nature of gym-goers, which unfortunately tends to inhibit their capacity to evolve and improve their wellbeing and body. So what is it about this war between “clean” and “dirty” foods that gets individuals so riled up?

Well, frankly, I have to believe that for people who are accustomed to restricting themselves to a select few “clean” food choices just get so overwhelmed with the contrary ideology that no foods are ever really off limits so long as you eat them within your dietary means that they discount the validity of such a position. The reason for this is likely because they have been inundated with misinformation by their trainer, the media, and/or the meathead bodybuilder in the gym that certain foods are inherently (and unanimously) healthy in all circumstances (and they denote these foods as “clean”).

The keyword in this instance is healthy; what constitutes a unanimous health-promoting food? Let’s use the example of a piece of boneless, skinless, hormone-free, organic, free-range chicken breast. What in your mind makes it healthy? Is it the protein content, bro, or the fact that it’s low in fat and carbohydrates (because we all know these are the “evil” macronutrients)? Is it the vitamin and mineral content? Is it the way it is was raised, or the fact that it wasn’t treated with hormones prior to its eventual fate in the slaughterhouse?

Barring specific food allergies or some inane fear of certain food additives (like monosodium glutamate), there is little basis to label a food as being unanimously “dirty” or unhealthy. About the only exception I can think of would be partially hydrogenated oils and mono-/di-glycerides due to the trans-fatty acid but even they are likely fine in (very) limited quantities, and I can’t remember the last time I met a health-oriented individual who was trying to get more trans fats in their diet.

Foods are dynamic

Frankly speaking, a food that is healthy will be relative to the organism and their environment. Therefore, in a Darwinian/biological sense, for something to be healthy, it would serve to enhance the survivability (read: fitness) of that organism. This is to say that foods are dynamic, and what is healthy for one individual may or may not be healthy for another.

Now that we have covered the dynamic nature of foods, what would constitute a food that is unanimously unhealthy (or “dirty”)?  The popular food used in defense of the IIFYM movement is the Pop-Tart since it is generally highly processed, contains moderate amounts of fat and sugar, and lacking micronutrient content.

But again, if you think pragmatically about this, there are very few foods/ingredients that are not beneficial in some capacity in at least one situation. Furthermore, many foods/ingredients, when eaten in moderation, can be healthy for an individual. People need to ditch the baseless idea that certain foods are completely taboo in all instances because it’s just not the proper way to view them. Nutrition is not as black and white as people seem to make it with the whole notion “clean” and “dirty” foods.

Therein lays the reason we can’t have nice things in the fitness and bodybuilding realm, because people have this damned all-or-nothing, extremist mentality and heaven forbid there be a middle ground. The subjective dichotomy of universally “clean” and “dirty” foods that we’ve been discussing is a perfect example of this; people look at certain foods and think “Oh, those are ‘clean’ foods, so I should just eat strictly those and abandon everything else.” If you’ve succumbed to such a lamebrain mentality towards food I suggest you keep reading.


IIFYM—a cerebral approach to dieting

The concept of IIFYM is actually rather intuitive if you think about it. I actually find it sort of laughable that it has taken this long for it to makes some headway in fitness/bodybuilding subculture since unbeknownst to them this is the way most humans have eaten their entire life.

IIFYM is pretty simple really—eat whatever you please so long as you meet your macronutrient needs at the end of the day. That’s it; no fuss, no muss, right? Well, of course, there are some finer points to be addressed here along with elaboration of why IIFYM works.

For starters, the physiological reasoning behind IIFYM is that the the body sees foods as proteins, carbohydrates, fats, and micronutrients, not as high-fructose corn syrup, enriched flour, or soybean oil, for example.

High-fructose corn syrup, no way that’s okay to eat, right? Wrong, it’s a sugar; it has the same physiological fate as sugar(s) from other food sources (and yes there is plenty of literature to backup that supposition). [1]

Not to go off on a digression here, but a popular IFBB pro bodybuilder (who shall rename nameless to save him face) made the unfounded claim that wheat flour causes colon cancer, of which I have yet to see one study even showing a correlation between the two. In fact, wheat flour is a good source of folic acid, which is actually inversely associated with colon cancer risk. [2]

The reality is there is little foundation to vilify and/or fear certain food ingredients, at least scientifically and physiologically speaking.

What IIFYM isn’t

Most people will interpret the preceding portion of this article to mean that IIFYM is an excuse to eat a diet composed purely of Pop-Tarts, ice cream, donuts, and pizza while disregarding micronutrient needs, fiber, and excessive simple sugar intake. If that’s your idea of IIFYM, you have not comprehended this very well.

IIFYM is a practical, modest (let alone logical/sane) approach to dieting whereby you meet your daily macronutrient and micronutrient needs with foods of your choice. Therefore IIFYM should really be called “IIFYM & µ”.

If you’re a health-oriented bro looking to get shredded abs (for the babes, of course), it’s highly doubtful your macronutrient needs will consist of tons of trans fats and simple sugars and little dietary fiber, so good luck meeting your macronutrient quota while eating nothing but Pop-Tarts and protein shakes all day.

Furthermore, we cannot discount the necessity of micronutrients. Again, good luck meeting your micronutrient needs eating cake and ice cream all day with a few chicken breasts littered in there for the “brotein”, bro (and no, popping a daily multi-vitamin does not confer the same benefits as eating whole vegetables and fruits).

So are there drawbacks to IIFYM?

About the only real drawback to IIFYM is that some people may lose grasp of the moderation concept. As noted earlier, foods are dynamic and should be promoting your health/fitness. In order for your diet to be doing this, you should be avoiding the extremes of taking in too much of a particular nutrient and/or being deficient in another nutrient, as well as meeting your daily goal for caloric intake. The foods you choose to eat to satisfy this are simply means to an end.

You might be asking, “Well, what about ‘trigger’ foods?” Sure, some individuals have a disoriented psychological relationship with certain food(s) which can send them into an uncontrolled episode of binging, so obviously I would have to advise against eating those particular foods. That being said, this is a psychological issue that this person needs to correct before it turns into a full-blown eating disorder.

Parting thoughts

For some people this article may be so contrary to their prior train of thought about nutrition that I come across as some Pop-Tart-loving mama’s boy that has a vendetta with the “clean-eating” bandwagoneers out there.

The irony of the whole IIFYM diet mantra is that people who follow it while trying to meet halfway decent macro and micronutrient quotas still end up eating lean proteins, whole-grain carbohydrates, essential fatty acids, vegetables and fruits. Notice I’m not calling these unanimously “clean, healthy” foods because that terminology is illogical; these are more properly foods I would call “nutrient dense” (and save the semantic arguments for someone else).

Don’t overlook the fact that food is often times a social relief for individuals; if you enjoy eating a few slices of pizza with your kids or taking your significant other out for a nice candle-lit dinner, then plan ahead and work that into your diet.

I don’t care how lean you’re trying to get, there is no reason you can’t make room in your diet for foods you genuinely like to eat while still achieving your physique and health goals. At the end of the day, it’s really just a matter of finding the proper balance...Ya’ know, that middle ground that seems to fly right over most fitness freaks’ heads.


1) Moeller S, et al. The effects of high fructose syrup. Journal of the American College of Nutrition. 2009;28:619.

2) Kim, Y. I. (2003). Role of folate in colon cancer development and progression.The Journal of nutrition, 133(11), 3731S-3739S.

Posted on: Tue, 01/14/2014 - 18:35

I fully understand that most reasonable and successful clean eaters understand how to practice moderation and understand that there's not really "clean" and "dirty" food. I also understand that most reasonable and successful practitioners of IIFYM know to get their micronutrients and fiber.

But where I have bigger concerns is that followers of IIFYM end up far more likely to experience blood sugar spikes than clean eaters, if they don't know to prevent them. Industry experts and people well versed in metabolic science -- Layne Norton, for example -- will explain that making sure to balance meals can avoid this, such as having adequate fats with your processed carbs. But most writing I see and opinions I hear about the superiority of IIFYM glaze over this. Periodic blood sugar spikes are bad news added up over time. They are not a guaranteed outcome of IIFYM but I wish this was part of the discussion more often, in the way that micronutrients are being included more often.

Cody Carlson
Posted on: Tue, 01/14/2014 - 17:21

From a bodybuilder and trainer who not only implements the "Clean/Dirty" classification of my diet, but rather enjoys doing so for a flurry of reasons, most of which are for the babes, I have witnessed both ends of the IIFYM debate spectrum. I can't say I personally condone the blind-eyed ignorance of justifying the protein content of a 12 piece fried chicken nugget combo with a powerade on the side, but knowing how to rationally 'cheat' in a moderately strict diet seems to be the most practical use of the controversial system. Anyways, I digress, bro, time for a protein shake and a pop tart.