IIFYM – what you need to know about flexible dieting

Автор: Станислав Чакъров

29 Nov 2015

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Since I’ve made a video about IIFYM vs Clean eating, the topic become viral in Bulgaria. But it seems that many didn’t understand what I meant by „Flexible dieting“. People tend to put words in my mouth. It looks like I said that you can eat junk and if that fits in your calorie intake for the day, you will still become muscular and ripped. Actually, I've never said that we should only track our calories and that the source doesn’t matter! All I said is that, if we consume more calories than we actually need, we will gain weight! No matter if they are from so-called „clean foods” or junk! I also stated that macronutrients are important if our goal is to achieve a good body composition. And of course, there are micronutrients and fibers. They have important implications for our health and the proper functioning of our bodies. I don't want to be misunderstood by our international auditorium like I was in Bulgaria. That's why I decided to write this article about IIFYM. I would like to show how I incorporate it into my diet. I've been following IIFYM for almost 5 years and I will keep doing so in the future. Read on to find out why!

What is IIFYM?

It is an acronym, and it means “IF It Fits Your Macronutrients”. For those who don’t know there are three macronutrients – protein, carbs, and fats. IIFYM is the practice of calculating the sum of macros and thus tracking calories. In essence, this forms our daily calorie intake.

It's is also called „flexible dieting“ because it gives you a lot of freedom to eat tasty foods, without interfering with your results. This principle is based on the laws of thermodynamics. In particular, the first law that applies to movement and conservation of energy. As far as this applies to biological organisms, this principle is complicated. In short, the first law of thermodynamics states that energy in an isolated system is constant. Energy can be converted from one type to another, but can not be created or destroyed. Of course, the human body is not a closed system and it exchanges energy with other external ones. When we eat food we take in energy. This energy can be stored as fat or converted into heat – another form of energy. The conclusion we can draw is that if we take more energy than we spend, we will store energy. If we receive less energy than we spend, we will lose energy. One of the biggest misconceptions about this principle is that energy is only stored as fat. Well, it’s not! The body has different energy stores such as muscles, fat, and glycogen in the liver. The first law of thermodynamics tells us only that we lose stored energy. But it does not tell us anything about the source. So, when the scale moves down and you lose weight, it may come from fat, but it could also be from muscle. This means that regardless of our food choices if we are not exceeding our caloric intake for the day, our weight will never go up. In short, IIFYM says: „You can eat anything as long as it fits into your macronutrients“.

And this is true if your goal is to simply gain or lose weight. But if you want to change your body composition, things are not so simple. Even in the video, I did on flexible dieting I was skeptical with the way most people understand IIFYM. In my opinion, many are abusing this type of “diet”. IIFYM is not a way to fit in as much „junk food“as you can in your diet. Many people do it just to show how cool they are – maintaining a visible six-pack while eating any kind of junk. You know those guys, right? They’re quite annoying! I don`t know why people think that IIFYM and clean eating are mutually exclusive. For some reason, most think that both diets are incompatible. Is it not possible to eat clean foods while keeping track of our macronutrients? Doing so can help us track our caloric intake. In the end, this will help us achieve our goals easier and in a more reasonable fashion.

Having a six-pack does not make you healthy

The first thing I want to emphasize is that having a six pack is not the same thing as being healthy! That someone has abs, does not make him a person with good health. And vice versa – just because someone has a more body fat, does not mean that he has terrible health. The same is true for a person that follows a flexible diet and eats some junk from time to time. That doesn't mean that he is living an unhealthy lifestyle and has bad health. I think the right way to implement IIFYM is to allow some „junk food“ here and there. Yet only when we have a stable basis that meets all requirements for a healthy and balanced diet, to begin with.


What I am trying to say is that you should not deprive your body of beneficial compounds such as vitamins, fiber, and minerals. Instead, first, you should focus on them. Once you are sure that you have covered your needs, you can include some unusual foods. By unusual, I'm referring to foods that don't fit into the stereotypical bodybuilder menu. To make this work, you also have to properly calculate the macros of the foods you select.

IIFYM and eating disorders

The second thing I want to emphasize is the fact that IIFYM could affect your mental health. Both positively and negatively. In most cases, IIFYM is an effective way to treat eating disorders. For example, it's perfectly suitable for hyperphagia (uncontrollable binge eating).

binge eating

This disease is included in the international classification of eating disorders. In recent years the worldwide incidence of hyperphagia has grown significantly. At risk are those that often follow aggressive diets and undergo periods of starvation. Often, the result is uncontrollable overeating and ultimately feelings of shame and guilt. There are even cases in which people stimulate vomiting to prevent digestion of the food. In the long term, overeating can cause serious depression, feelings of shame, guilt and disgust. This stimulates people to overeat even more often to soothe themselves. Of course, this doesn`t help, but only worsens the problem. In the end, it becomes a vicious cycle of overeating and self-pity. Flexible dieters know what macronutrients are contained in their food. They know exactly how much they can afford to eat, without impairing their diet. Hence bouts of overeating, depression, regret and a shame are less common. Yet, in rare cases, IIFYM can cause disordered eating as well. For example, some people have replaced almost all „clean“ foods with „junk food“. This phenomenon occurs frequently in those who are just beginning to use a flexible diet. Once they see that eating waffles and pizza doesn’t impact their body composition negatively, adding some ice cream and cookies in the mix is not far off. In such instances, people will continue to replace the foods they usually eat with „prohibited“ ones. You must approach flexible dieting with caution. Don't use it just to cram as much junk in your diet as you can. The most important thing is to have self-control. Your body needs the nutrients contained in natural products. If you drop them completely from your menu, then it is a matter of time before you feel the negative effects of IIFYM.

Let's not forget that to achieve a nice body composition we need to balance protein, carbs, and fat. By stuffing your face with „dirty food“ you can reach your carb and fat targets for the day with ease. Yet, your protein will remain low. In effect, you won't even have enough calories to fit in healthy foods! If you want better body composition, a good balance of macronutrients is essential. And to achieve that you need „clean food“ by default. As already mentioned, this problem with IIFYM followers is extremely rare. Most people who have followed clean eating, approach this diet carefully and with distrust.

Running out of calories

Another reason to not score only junk in our diet is the feeling of satiety. This is a factor that is quite important and often overlooked. Natural foods are more filling than „dirty food „, which is a big plus when you aim at reducing weight. It is also important to remember that we can get the same calories from food with different volume. For example, 200 calories we can get from 40 grams of potato chips or a 40 gram Snickers bar. Yet, this can also be obtained from 380 grams of apples or 3 ( 150 gr.) whole eggs! When you're in a caloric deficit, you have to pick your food with care. Otherwise, you might stay hungry. As I stated above, systematic starvation can lead to uncontrollable overeating! Overeating is the last thing you want to happen when you try to lose weight. Use filling foods that are low in calories, but are large in volume. In this way, you will not risk having all your calories before noon and carb-load an entire box of waffles in the evening.

The benefits of IIFYM

Once we learn to track our macronutrients, we can make up our daily menu as we like. We can fit it to our individual lifestyle, without having to exclude all the foods we love. Many people give up their desired body composition just because they believe that they can`t follow a healthy diet.

If I have to be honest, I would quit if I had to eat 6 small meals per day. Especially if 3 of them are boiled chicken breast with broccoli, quinoa with cheese or bland rice with unseasoned salmon. Many of us are not able to eat as often. Also, some may not have the financial means to afford expensive food. Especially when certain foods are described as the key factor in weight loss diets. IIFYM allows you to follow your free time as well as your finances! You're not obliged to eat superfoods constantly. You can choose seasonal and fresh foods instead!

IIFYM as a skill

IIFYM's huge plus is that when applied long enough, becomes quite intuitive. When you apply a flexible diet, over time, you become skilled enough to guestimate. If you practice long enough you can guess the exact weight of a food without having a kitchen scale next to you. So, when you go out, you can calculate estimates of consumed calories only by looking at your food! IIFYM enables you to go out with friends for pizza without feeling guilty that you have cheated on your diet. Just leave enough macronutrients for the evening. When you go out with friends, remember that the goal is to have fun and do not deny yourself from the best moments in life.

The most important conclusions about IIFYM

Contrary to the perceptions of some people, flexible dieting does not exclude healthy food. Quite the opposite whole foods should be the foundation of IIFYM. IIFYM is a diet that gives us enormous freedom and extreme flexibility in our eating style. I place special emphasis on flexibility because we do not live in an optimal world where everything revolves around our diet and aspirations to gain or lose weight. We all have a family, work, university, school and other responsibilities that will always be present in our lives, whether dieting or not. Your friends are not obliged to comply with your desire to exclude certain foods from your diet. Quite often they will eat awesome food right in front of you. Things that are prohibited by your coach or the diet you follow.

In such situations, it's easier for some people to be antisocial and stay home, instead of going out for a nice dinner with friends. This will cause you to miss many nights filled with priceless memories that would give you energy, and motivation.

What we learned in this article

You cannot sustain a healthy diet with cakes, pastry, and junk food. These foods are void of many important micronutrients. Furthermore, their macronutrients favor fats and carbs instead of protein and fiber. Hence caloric intake will accumulate quickly with little effect on satiation. The truth is somewhere in the middle. We want to get as much out of IIFYM. This means not to deprive yourself of your favorite foods. To look and feel good without your clothes on. To be healthy, strong and confident. Can we do this by stuffing ourselves with junk food? Maybe for a little while, this is possible. Yet long-term this is no good. To reap the benefits of IIFYM we need to have 80-90% clean foods. The rest is enough to provide us with enough flexibility. In this way, we can eat our favorite foods in moderation, without having to miss important moments with our friends and family. It is true that people are in a calorie deficit will lose weight regardless of the source of calories. Yet, if you abuse junk food this will not be long-lasting nor is it optimal for body composition and health.