You’ve probably heard the term: ‘If It Fits Your Macros (IIFYM)’, also known as ‘flexible dieting’. This means that it does not matter what you eat for body composition (muscle growth and/or fat loss), as long as you eat the right amount of calories and distribute them in the right way over the macronutrients (proteins, carbohydrates and fats). Of course, if you like snacking, that sounds tempting. But is it also true?

‘GOOD’ VERSUS ‘BAD’ FOOD

Many bodybuilders think that there is ‘good’ food (which makes you build muscle) and ‘bad’ food (which makes you store fat). A classic fallacy, fed by hip healthy eating coaches. They often (unintentionally) suggest that the nutrients from chicken and rice go straight to your muscles, and that a hamburger is mercilessly turned into body fat. As a result, many bodybuilders think that they can eat unlimited healthy food, because that does not make you fat, but muscle.

But that’s not how our bodies work. It does not ‘think’ in terms of ‘healthy/good’ and ‘unhealthy/bad’ food. Your body responds to individual nutrients you ingest (macro and micronutrients) and to the total amount of food (calories), regardless of the food sources. Whether you gain or lose weight depends on the total calorie intake in a day, whether it comes with chicken and rice or hamburgers. In addition, for muscle building, the amount of proteins you ingest counts, again regardless of which source they come from.

Picture it as three cylinders side by side: proteins, carbohydrates and fats. At the end of the day, all three should be filled to a certain height. With which substances the tubes are filled, it does not matter for muscle growth or fat loss, as long as the amounts are correct.

Strictly speaking, the foregoing means that you can build muscle or lose fat even with a mere unhealthy diet. Because it doesn’t matter what you eat, as long as you do it in the right amounts. This theory is the basis of the If It Fits Your Macros principle (IIFYM).

Let’s see if IIFYM is indeed a good strategy for muscle building and fat loss.

IIFYM FOR MUSCLE BUILDING

Food provides you with calories (energy) and macronutrients (proteins, carbohydrates and fats). Each macronutrient facilitates important functions in your body, such as maintaining and building muscle mass. For example, the amino acids from proteins are the building blocks of muscle tissues, carbohydrates provide energy for strength training, and fats maintain the level of testosterone, among other things. In addition, most people need a calorie surplus for muscle building , so that the body has enough energy available for the process of muscle protein synthesis.

In our article on bulking (eating for muscle building) we take a detailed look at the optimal amounts of calories and ‘macros’ for muscle growth. In short, they mean this on average:

• energy (kcal): 10-20% above maintenance level
• protein: 1.6-2.2 g/kg body weight
• fat: 1-1.5 g/kg body weight*
• carbohydrates: the rest

* of which 25-50 percent saturated fat, and the unsaturated fats evenly distributed over simple and multiple

According to the IIFYM principle, it doesn’t matter which food products you eat, as long as you have achieved the above goals at the end of the day (about then). You can keep track of those goals fairly easily by means of a calorie app, a tool that we believe is indispensable if you want to improve your body composition.

Now, to a certain extent, that IIFYM principle is also true. Muscle growth starts with the right calorie intake. If you don’t eat enough, your muscles can’t grow, no matter how well and healthy you eat, and no matter how well you distribute your macros. Calories are closely followed by proteins. If you don’t get enough of that, your muscles can’t grow optimally, even if you eat enough calories. The distribution of the remaining macros – carbohydrates and fats – is less important.

Yet it is too short-sighted to say that the quality of food does not matter (for muscle growth, that is). Food also contains vitamins and minerals, the so-called micronutrients. They help with all kinds of vital processes in the body, including muscle growth. It is not without reason that some micronutrients, such as zinc, magnesium and vitamin B6, popular as a bodybuilding supplement. For example, if you have a magnesium deficiency, you will suffer from stiff muscles and cramps. A deficiency also leads to fatigue, which can be at the expense of performance during strength training. (Strength) athletes also need more magnesium than non-active people. And no, magnesium is not in pastries or chips, but in whole grains, vegetables, nuts, milk and milk products and meat.

Micronutrients are also important for your overall health, something the aesthetically focused bodybuilder sometimes wants to forget. Good health is also indirectly important for training performance and recovery.

The importance of micronutrients may not apply in the short term: a week of unhealthy eating according to IIFYM will probably not have a negative effect on muscle growth. But if you always eat mostly unhealthy, it will not only negatively affect your health, but also your body composition.

Calories and macronutrients are the two most important aspects of nutrition in building muscle. Source: Eric Helms.

We believe that the quality of nutrition is indeed important in a bodybuilding diet. But one should not overdo it either. If you search for ‘bodybuilding food’ in Google Images, you will mainly come across pictures of baking with rice, chicken and broccoli. Self-proclaimed fitness gurus would still have us believe that these foods contain magical powers for muscle growth (mainly “explaining” their own supernatural physiques). That is not the case. It is not the case that some types of food ‘generate’ more muscle growth than others. There are also many other responsible ways to get proteins and carbohydrates than through chicken and rice. It is personal preference that makes the difference. Bodybuilding coach and author Mike Israetel says about this:

Outside of personal preference and digestive comfort, there is no rational basis there for choosing a specific whole grain, veggie, healthy fat or lean protein over another. Focusing on healthy choices within set macros is 99.9% of the equation!

As a bodybuilder, therefore, ensure a healthy diet, composed of the right amounts of calories and macros, and with sufficient micronutrients. Choose responsible foods that you enjoy and that are easy to prepare to integrate into your daily life. In the bulk, it’s okay if you also want to snack on something, as long as that remains within limits and does not come at the expense of the intake of micronutrients.

IIFYM FOR FAT LOSS

Losing weight, in the sense of fat loss, is very simple: eat less than you consume. Or: calories in, calories out. Point. Yet losing weight is still unnecessarily complicated, especially by diet gurus who can thus earn fat from their ‘method’. And that while research shows that it doesn’t even matter for fat loss whether you go low carb or low fat.

Even if you’re a bodybuilder, realizing fat loss (cutting) is no higher math. The guidelines:

• energy (kcal): 20-25% below maintenance level
• protein: 1.8-2.7 g/kg body weight
• fat: 0.5-1 g/kg body weight
• carbohydrates: the rest

The energy balance (calories) and macros are also decisive for fat loss. Even if you only snacked, you can ‘just’ lose weight, as long as you stick to those amounts. This has also been shown several times in (playful) studies, such as the professor who lost weight by eating only cookies and chips , and the American who lost more than 13 kilos of body weight by drinking only beer. In these cases, even the macros weren’t even important, as long as the desired calorie deficit was met.

However, we do not recommend snacking during a calorie-restricted diet. First, because snacks are high in calories, leaving little caloric space for nutritious food sources. And it is precisely with a long-term calorie deficit that you have to ensure that you get enough micronutrients. Okay, that can also be done by taking a supplement (multivitamin). Second, snacking on a calorie restriction just makes dieting unnecessarily difficult. As mentioned, snacks have a high calorie density, while providing relatively little dietary fiber. As a result, they don’t really make you feel satiated and they usually taste like more. Third, eating healthy while on a calorie-restricted diet also works psychologically better. By completely banning unhealthy treats from your diet and from your field of vision, you will think and crave them less.

In short, in theory you can certainly lose weight according to the IIFYM principle, but in practice you make it unnecessarily difficult for yourself. In addition, by combining diet with exercise, bodybuilders have a greater need for micronutrients. To get the full range of vitamins, minerals and fiber, it is best to ensure a healthy, balanced diet during the cut.

IIFYM (FLEXIBLE DIETING): THE HEART OF THE MATTER

IIFYM is formally also referred to as flexible dieting. It means you have a wide choice of foods to fill in your macros. But that doesn’t mean you can eat mostly unhealthy foods.

Coach, author and podcaster Eric Helms explains this by means of two statements:

You have flexibility to select from a wide range of food sources in accordance with your goals and preferences. There are no foods that are fully off limits for fitness enthusiasts.

The second statement reads:

Food source selection doesn’t matter.

According to Texler, the first statement is correct: as a bodybuilder you are not bound to the well-known small list of foods: white fish, chicken breast, rice, sweet potato and broccoli. There are so many other options for filling in your macros. However, that does not mean that food selection is completely unimportant (statement 2). We have already seen that things such as vitamins, minerals and satiety also play a role.

Bottom line: IIFYM or flexible dieting is a good diet strategy as long as it doesn’t become a license to snack.

SUMMARIZED

1. There is no ‘good’ or ‘bad’ diet for body composition (muscle building and/or fat loss). In principle, it is about the total amount you eat (the calories) and the ratio of proteins, carbohydrates and fats (macronutrients). Even if you only eat healthy food, if you don’t get the calories and ‘macros’ right, you will not be able to build muscle and/or lose fat optimally.

2. According to the principle If It Fits Your Macros (IIFYM), dieting is purely a matter of using the right numbers. To some extent it is, but it shouldn’t be a license to snack a lot. It is also important to get enough micronutrients (vitamins, minerals and fiber). After all, they also (indirectly) influence muscle growth and fat loss.

3. As a bodybuilder, ensure a healthy diet, composed of the right amounts of calories and macronutrients, and with sufficient micronutrients. Choose responsible foods that you enjoy and that are easy to prepare to integrate into your daily life. It’s not a problem in the bulk if you want to snack on something, as long as that does not come at the expense of the micronutrient intake. Use a calories app to monitor all this.

4. During a calorie-restricted diet (cutting) it is best to eat completely ‘clean’. Snacking only makes dieting unnecessarily difficult.