Finding Your Best Macros
IIFYM- ‘If it fits your macros’- is one of the most popular styles of flexible dieting used by gym goers and athletes alike. It allows you to meet your weight goals without being overly draconian: you shouldn’t feel particularly restricted using IIFYM, and you shouldn’t find yourself getting hungry as you’re losing weight.
IIFYM is different to most diets in that it puts the focus on macronutrient intake rather than calorie consumption and limited types of food. This allows you to enjoy a greater degree of flexibility in your eating habits as all foods can be included, as long as they fit within your daily macro targets.
IIFYM: What Is It?
It only requires a few simple steps:
Step 1: Calculate your macronutrient needs.
There are calculations available (I’ll go into this in more detail below) to help you determine how much of each macronutrient your body needs.
Step 2: Meet your calculated macros.
When you’ve worked them out, stick to them. Eat however much of each macronutrient you need each day, no more, no less. Track your weight and adjust as needed.
All foods are permitted on the IIFYM diet. If you want to, you can eat nothing but pizza and protein shakes, as long as the macronutrient load you get from them fits your requirements. This is the liberating part: for people used to having to eat low yield salads whilst staying clear of cake, chocolate and alcohol, suddenly putting these treats back into a framework that allows them to hit their goals is a bit of a godsend.
Most people use IIFYM to either lose or maintain weight. However, it can also be used to gain weight. I often use it in part myself to control for lean muscle gains in the gym, keeping relatively flexible whilst minimising fat gains as I go through a hypertrophy (muscle building) phase. This means that I get to build muscle, not put fat on, and eat a fairly varied, flexible diet.
What Are Macronutrients?
This all begs the question: what are these macronutrients that IIFYM is so eager to regulate?
All foods can be categorised by macronutrient. There are three main macronutrients: proteins, fats and carbohydrates. Few foods are solely one or the other, and instead will be a combination of all three.
To use a popular example, let’s look at bananas. A medium banana will typically contain around 0.4g of fat, 27g of carbohydrates, and 1.3g of protein. Though they are predominantly a carbohydrate source, we can see there are also minimal amounts of fat and protein. On the other hand, a large egg will give you around 5g of fat, 0.6g of carbohydrates and 6g of protein, making them ideal for getting fat and protein into your diet, but less so for carbs.
But what are these macronutrients, and what roles do they play in your body that makes balancing them correctly so important?
What are Carbohydrates?
Carbohydrates are the body’s main energy source. They are formed from chains of sugars that your digestive system breaks down before absorbing them as glucose. Glucose is your body’s preferred and most efficient energy source and is vital for brain health and concentration, among other things.
Most diets will need to be made up of anything from 45-65% carbohydrates, making them the fundamental building block of your eating plan.
Plant-based diets in particular thrive on carbohydrate intake: carbs are found in abundance in the majority of plants. When you’re structuring your IIFYM plan, try to take as much of your carb intake as possible from fresh fruits, vegetables, legumes, beans and pulses, as these are the healthiest choices. They contain plenty of fibre and nutrients and will also often provide you with some of your daily protein need.
Fibre is an indigestible form of carbohydrate that will play a large roll in your diet. Not only does it increase satiation- meaning that you will feel fuller from less calorically intense foods, on a reasonable macro balance- but it is also vital in maintaining digestive system health. It bulks out your stools, decreases cholesterol, and feeds your gut bacteria, among other benefits.
However, as the name suggests, sweet, sugary food is also allowed on the IIFYM diet- as long as the carb intake from these fits within your daily macro requirements.
What are Fats?
A lot of people steer clear of fat when they are dieting for weight loss. They couldn’t be more wrong to do so. Though it is calorically dense, it is essential both for losing weight and for maintaining a healthy body.
It plays a key role in brain development and function, and cell production, regeneration and normal functioning. It is also vital in the absorption and transportation of fat-soluble micronutrients like Vitamins A, D, E and K, as well as the carotenoids found in plant-based food sources.
A normal, healthy diet will need to be made up of around 15-20% fat. For healthy fats, look to foods like avocado, nuts, fish, seeds, oils and olives. However, as with sugary carbs, as long as it fits your macros, all fat sources will be fair game on the IIFYM diet (though I would limit the amounts of kebabs and fries you include, if you want your health to remain intact!)
What are Protein?
Protein is made from amino acids. These acids form the building blocks of many bodily structures, such as muscles, organs, soft tissue and so on, as well as enzymes and hormones. Hence, protein is vital for maintaining healthy bodily structures.
A healthy diet should be made up of 15-30% of protein. Those with more physically demanding lifestyles like athletes or labourers will typically need more than this as their bodily structures (i.e. muscles and soft tissue) come under more constant, high-level stress than more sedentary individuals.
Healthy and abundant sources of protein include animal products such as lean red and white meat, eggs and milk products, as well as plant-based sources like nuts, quinoa, seeds and other grains. However, as with carbs and fat, any source will do as long as it fits your macronutrient targets.
How To Calculate Your Macronutrient Needs
Of course, the most important part of embarking on an IIFYM diet is calculating your macronutrient requirements. This is easier than it sounds: the IIFYM website provides a free calculator, if you want to keep things simple.  Alternatively, you can do it yourself manually. Simply follow these three easy steps:
- Calculate your basal metabolic rate (BMR) and adjust this BMR for your activity levels to find your total daily energy expenditure (more on this below.)
- Adjust this new level to meet your weight goals. Generally, a daily deficit of around 500 calories will lead to a weekly weight loss of about 1lb/0.5kg, and vice versa.
- Now determine your macronutrient load based on this adjusted BMR. In very broad terms, it’s worth starting off at a split of 50% of your calories coming from carbs, 30% from protein and 20% from fat. These can be adjusted according to your own goals and requirements, and as you figure out what works best for you going forwards.
Calculating Your BMR
Calculating your BMR, and using it to calculate your caloric needs, is actually very easy.
There are many BMR calculators available online, which will work off one of several equations. Once you’ve worked out your BMR, you will need to multiply it upwards to find your caloric need at your activity level. Simply find the multiplier below that seems most relevant to your activity level:
- Little/no exercise: BMR x1.2
- Active: BMR x1.55
- Very active: BMR x1.9
So, for example, I weigh a quite hefty 95kg (210lbs) and am very active- I walk my dog several miles every day and train hard in the gym 3-4 times per week. Using a BMR calculator like ours, I find that my BMR is 1885. If I multiply this by 1.9, because I am ‘very active’, I get 3581. This means that I need to eat roughly 3,581 calories per day to maintain my current weight.
Calculating Your Macro Needs
Let’s use my numbers from above. If I wanted to lose 0.5kg/1lb per week, I would need to hit an average daily deficit of 500 calories, meaning I would need 3,081 calories daily. If I wanted to put on 0.5kg/1lb per week, I would need to hit an average daily surplus of 500 calories, meaning I would need more like 4,081 calories.
Let’s say I want to lose 0.5kg/1lb per week for four weeks. We’ve seen that this means hitting around 3,081 calories per day. At the split I’ve suggested above, we’re looking at 50/30/20 of carbs/protein/fat. Therefore, I would want 50% of my calories from carbs, so that 1,540 calories. I would want 30% from protein, so about 925 calories. Finally, I want 20% from fat, giving me 616.
Each gram of protein and carbohydrate contains four calories. A gram of fat contains 9 calories. This means that I want my diet to be made up of:
- 1,540/4= 385g of carbs
- 925/4= 231g of protein
- 616/9= 68g of fat
These are the macros I’ll be working towards. As long as what I eat adds up to these every day, I should have enough of everything I need to be healthy and energetic (and to recover from the gym, hence the large, 30% portion of protein) whilst remaining in the deficit I need to lose weight.
How To Meet Your Macronutrient Needs
When you know how many of each macronutrient you need, you are ready to get started. Now you will need to track your food intake to see whether or not you meet your macro targets, and by how much you will need to adjust them.
There are several websites and apps that make this process a lot easier, helping you to keep track of your macros and regain control over your diet:
I would always recommend buying a set of accurate, electronic cooking scales so that you can weigh ingredients as you’re making your meals. This will make it easy to see the quantities of an ingredient as they go into your food. Then you can simply Google each ingredient and see the ratio of each macro.
This may sound a little daunting at first. It can be time-consuming as you get used to the process. However, it becomes a lot easier with time, as you both get used to the process, and learn what macros your favourite ingredients contain.
How IIFYM Compares To Other Diets
The main reason people turn to IIFYM is for the flexibility it affords. If you want that slice of cake, you can have it: you simply have to take note of the macros you just ate, and make sure there is room for them in your daily allowance.
Another reason is that you won’t be starving yourself. Of course, in order to lose weight, you will have to be in a caloric deficit. However, this is a far cry from some of the ultra-low calorie, unsatisfying diets that most people think about when they think about shedding fat.
This being said, let’s look at some of the pros and cons associated with the IIFYM diet.
The Pros of Flexible Dieting
You can have your cake and eat it – Even with the types of food you would normally avoid like the plague on a weight loss diet, body fat and overall weight can be decreased. Though some people might criticise this approach, it has been proven to work.
You will be in good company – Many top tier athletes have made good use of the IIFYM diet. Well known Olympians, sports personalities, and even an on-screen superhero or two, have begun to make space in their diets for pasta, pizza and plenty of fried food among other things.
You will be able to keep to your goals – If you are used to bacon sandwiches, pies, alcohol and chocolate, suddenly converting to a diet of lean protein and steamed veg is going to be something of a culture shock. It’s little wonder that people struggle to keep to these kinds of diets.
With IIFYM, you can still eat the foods that you love and are accustomed to. All it takes is a little re-jigging to make them work for you.
IIFYM: The Cons Of Flexible Dieting
What about the micronutrients? – A nutritional plan that focusses entirely on macronutrients arguably misses half the picture. With so much attention given to macros, essential micronutrients like vitamins and minerals don’t get a look in. Of course, you can eat fried junk food and lose weight, but you’ll be running a nutritionally void eating plan with regards these micronutrients. Even the most die-hard IIFYM dieter should make use of multi-vitamin supplements at the very least. Most only ‘cheat’ a few times per week, and eat healthy food for the rest, to avoid this very pitfall.
You may have a different lifestyle to the pros – Though high-level athletes and consummate gym goers may love IIFYM, this does not mean that it will work for you. Quite simply, their days will not look like yours if you lead a normal, 9-5 office job lifestyle. Top tier strongmen routinely eat 10,000 calories daily. If you go to the gym three times per week and spend your life at a desk, you will likely need about a quarter of this. Suddenly, that calorically dense food that the IIFYM lets you eat (1,500 calorie pizza, anyone?) really doesn’t seem to go too far.
Your health is more than what you weigh – Being slim doesn’t mean you’re healthy. Losing weight when you need to will always be a good thing, as will building a firm, strong musculature beneath it. However, these don’t account for your internal health. Blood sugar levels, LDL (bad) cholesterol, visceral fat, blood pressure, iron levels, testosterone output… the list goes on for biomarkers that provide feedback on your internal health. These can all be vastly disrupted by bad foods.
A varied, healthy diet filled with fruit, veg and well-sourced protein will give you plenty of phytochemicals; we’ve already gone over what micronutrients can do for you; and certain fats and plenty of fibre will do wonders for your cholesterol levels and digestive health. These are all unaccounted for on the IIFYM diet in its most basic form.
Final thoughts on the IIFYM diet
The IIFYM diet in essence is a good idea: I’ve used elements of it in my own nutrition program for a long time. In the extreme, however, it falls apart. A diet solely made up of pizza, protein shakes and diet coke will not make you healthy, even if it hits your macros and keeps your weight down.
So, feel free to substitute healthier options for treats, making room for cake by diminishing rice intake, for example. But keep it sensible and moderate. Eat your greens, take in healthy sources of protein and fat every day, and keep the treats as what they are- treats, eaten sparingly.