'If It Fits Your Macros: You Need to Know The Truth


If you've done any kind of diet, you've probably heard about "If It Fits Your Macros" (IIFYM).

The crux of this 'diet' is that you can eat absolutely everything you want (yes, even pizza) as long as it keeps within your daily macronutrient goals.

But IIFYM is the epitome of the case of what's possible vs what's optimal. 

Can IIFYM work? In some cases, yes.

Is it optimal? No. And anyone who works in the real world with real clients can attest to this.

The aim of this piece isn’t to rant about the evils of IIFYM, but to discuss our experiences of what we feel works and doesn’t work in the IIFYM model.

Having delivered exceptional transformation results with thousands of clients, we know what works and what doesn't when it comes to body recomposition.

14-week transformation


What is IIFYM?

The original intention of IIFYM was to allow people a little flexibility into the diet outside of the traditional ‘clean’ foods and still improve their physique.

However, what started as an alternative name for ‘sensible eating’ has morphed into a pro-junk food diet where anything goes, as long as it ‘fits your macros’.

A Calorie is a Calorie...

To lose body fat you need to be in a calorie deficit. 

‘Calories in vs. calories out’ is, and always has been, the number one factor in improving body composition.

The first step for anyone looking to get into better shape should be to get your calorie intake in order.

But does this mean you can have your cake and eat it (quite literally)?


The calories in vs calories out model suggests that you could replace your breakfast with chocolate cake and this would still help you keep the weight off in the long run. 

The problem with this formula is it assumes all calories are equal, and that humans are robots disciplined enough to be able to consume a small piece of cake and then leave it at that.

If our goal was solely weight loss, looking only at calories may be a viable option... for a short while.

However, our goal with clients is always to build muscle and lose body fat. And to do this, we also need to consider the quality of the calories consumed.

This is where protein intake, for example, becomes important.

If we look at the first popular form of IIFYM, Weight Watchers, one of the issues was a lack of protein intake. 


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A diet deficient in protein while in a calorie deficit leaves the body susceptible to muscle loss, and the ‘soft, saggy’ appearance you commonly see in chronic dieters.

Another argument for protein is its thermic effect on the body.

When you consider that approximately 30% of calories from protein are used in digestion compared to almost nothing from fat calories, you can quickly see how looking only at ‘calories in, calories out’ is misleading.

In recent years, the IIFYM debate seems to revolve around whether the quality of macronutrients matters. And essentially that ‘if it fits your macros’, it’s fine.

From a strict energy perspective, this is true; 1g of fat is nine calories, no matter where it comes from.

But what about the effect different sources of food have on the body?

Is a carb a carb? Are all proteins created equal? Are all fats the same? 


To build muscle and lose fat effectively, aiming for a protein intake of 0.8 to 1.2g per pound is a good general guideline.

However, where the problem arises is that there are 'complete' and 'incomplete' protein sources. 

In an IIFYM-type diet, it wouldn’t matter where these proteins come from. 

So, 200g of protein from tofu, bread, rice and beans should create the same physique as 200g of protein from grass-fed beef, chicken and eggs. Yet we see time and time again that this isn’t the case.


To optimally retain and build lean tissue, you need to focus on maximising muscle protein synthesis through consuming foods with a full spectrum of amino acids.

So can I just eat a kilo of steak for dinner to hit my ‘quality’ protein for the day?

If you want optimal results, it probably isn’t advisable.

For the best body compositional changes, protein distribution does matter.

Comparing two sets of two groups of people - one set who ate their protein at dinner only and another who spread the same amount over three meals - muscle protein synthesis over the week would be 25% higher in the group with the protein intake distributed over several meals.

This is why eating three to six meals a day consisting of complete proteins works so well, especially if building a better body and not just ‘losing weight’ is the goal.



The easiest way to explain the difference in carbohydrate quality is to pose this question:

Are 100g of carbs from chocolate the same as the equivalent of sweet potatoes?

From an energy standpoint, sure it’s the same.

But what it fails to consider is the difference in the insulin spike that each will give, and the effect it will have on blood sugar control and satiety.

So, 100g of carbs from sugary foods, especially those combined with salt and fat, will only leave you craving more of the same after you’ve finished.

Adherence to the diet is the most important factor for anyone looking to get into shape. If you’re constantly famished with an unstable blood sugar level and a lack of satiety, chances are you won’t last long on a diet.

At Ultimate Performance we place a strong emphasis on using carbohydrate sources with lots of volume and high nutrient densities - foods like broccoli, cauliflower, sweet potatoes and even oats.

The advantage these foods have over sugary foods like chocolate are their ability to volumise in the stomach without changing the calorie content, which will help keep you more satiated for when the diet starts to get tough.



By now you probably know where this section is heading, and it should be clear that getting your food from quality sources is key.

With the growing use of junk food to ‘fit into your macros', there’s also a growing consumption of trans fats. If ruining your cholesterol and damaging your insulin sensitivity form part of your goals, then, by all means, add some more trans fats into your diet.

What are some of the lesser-known implications of IIFYM?

1. Digestion

When you consider that the majority of our clients are highly stressed with years of bad eating and lifestyle habits behind them, you’ll know why recommendations coming from 20-something-year-old IIFYM zealots make zero sense.

For these clients, the majority of their digestive tracts are not functioning anywhere close to optimal.

Further barraging an already dysfunctional system with pop tarts and jelly babies to reach a certain quota will only backfire.

Between 70% and 80% of your immune system is found in the gut, which means keeping it healthy is paramount for overall health.

Another interesting fact is that the bacteria in your gut play a role in the cravings you experience.

If you keep feeding bad gut bacteria with junk food, you’ll keep craving junk. If your diet is based around healthy, single-ingredient foods, your body will start to crave healthier foods. Which is always a bonus when you’re dieting!

Within a few days of starting a new transformation with us, clients always rave about their new-found energy levels.

LEG day

This isn’t some secret supplement we’re giving them. Instead, it’s their body finally being able to utilise and assimilate the nutrients it is being fed. 

By cleaning up the diet with high-quality foods, the gut starts to function more efficiently and begins to properly derive energy it needs from food.

An important note to consider is that sometimes even the best single-ingredient foods don’t agree with everyone. 

For example, eggs are common allergens, and many people don’t feel great after eating them, especially prolonged consumption.

At UP, we want the best body composition results in the shortest possible timeframe. To do this, we need all cylinders firing. The digestive tract is an important piece of this puzzle, so keeping it happy with quality nutrition that agrees with you is essential.

21-week transformation

2. Micronutrients

If you’re using fat and carb quota to eat Jelly Babies and deep fried pastries, chances are you’ve got some micronutrient deficiencies.

Sadly, it’s not only about protein, fat and carb numbers. Micronutrient deficiencies are important for not only your ability to recover from training, protect from injuries and lose body fat, but for your overall health.

If you’re not healthy or have a weak immune system, you’re going to find it hard to build muscle or lose body fat.

While you may be able to get away with the empty nutritional value junk food in your 20s, chances are it’s going to catch up with you in your 30s and beyond.

Junk food

3. Bodybuilder’s edge

If you want to study how to get lean, look no further than those who do it best: bodybuilders.

If IIFYM is as great as it’s been made out to be, why is it that even the absolute genetic elite aren’t using it?

Bodybuilders have known for decades now that to get lean you need to do three things: 

1. Create a calorie deficit,

2. Cut out junk food, 

3. Do this for an extended period of time.

At the most competitive level of bodybuilding, everything matters and they are all looking for the extra edge. The fact is no one at the top level is using IIFYM.

If it were a superior method of eating for optimal body composition, bodybuilders would be using it.

Bodybuilder Nick

How would we integrate IIFYM?

All being said, there are some good principles in IIFYM that can be implemented into any dietary approach.

What IIFYM has opened our eyes to is that there is more to life than simply chicken and broccoli. 

It does provide some flexibility into your diet that can be beneficial from an adherence and mental standpoint; two overlooked factors in successful long-term dieting.

The key phrase here is 'long term.' Short, dramatic transformations in regular people very rarely come from adopting an IIFYM approach. 

If long-term maintenance and slower results were the aims, then allowing a more ‘flexible’ approach whereby including ‘treats’ now and then can help ensure adherence.

We like to call this 'sensible eating.'

The second instance whereby including some elements of IIFYM works well is for our muscle-building clients who are pushing the ceiling when it comes to calorie intake.

This is where including 10-20% of your calories from less traditional ‘clean’ food choices can make life a lot easier. Of course, this is down to the individual client, and ultimately the decision should be based on what feels best for the client.

Lean and healthy

Application to UP Clients

With the clients we deal with at UP, we almost always need to create an overhaul in their dietary approach.

With the little time we are often given to create a dramatic change, we need to make sure the client’s plan is as easy as possible to follow.

Given the high stress and busy environment of our client’s lives, adding to this by asking them to count calories, macronutrients and plugging it all into an app calculator is never going to end well.


The message we wanted to put across in this piece is that there is more to macronutrients than meets the eye.

Yes, they’re important, but looking only at the effect the numbers would be looking at body composition through a small straw.

IIFYM will work if you want average results, but as industry leaders, we demand excellence through optimisation of all variables.

Managing digestion, micronutrients and inflammation are all key in transforming regular, real world clients.

In the long run, a sensible eating approach is best.

This means basing the majority of your diet around a wide variety of single ingredient, ‘cleaner’ foods.

Any time someone tells you junk food on a daily basis is the ticket to get lean, your BS-meter should be going through the roof.

In an industry filled with gimmicks, fads and false promises, if it sounds too good to be true, it more than likely is!


Jakubowicz, D., Froy, O., Wainstein, J., & Boaz, M. (2012). Meal timing and composition influence ghrelin levels, appetite scores and weight loss maintenance in overweight and obese adults. Steroids , 887-889.

Mamerow, M., Mettler, J., English, K., Casperson, S., Arentson-Lantz, E., Sheffield-Moore, M., et al. (2014). Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults. Journal of Nutrition , 876-880.

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