For those people who are into carefully planning their meals, there are now a ton of different options for healthy eating plans — from meat-loving paleo to vegetarianism and veganism and everything in between. With so many options for clean eating, it can be hard to know exactly which eating style is a good fit for you. Now that many people regularly hit the gym and want their meals to match their workout habits, it makes total sense that there’s yet another crazy-healthy diet making waves: If It Fits Your Macros.


What is IIFYM?

Originally used in the body-building community, the IIFYM diet has made its way to mainstream fitness enthusiasts and isn’t showing any signs of slowing down. “Instead of just counting calories, which gives little guidance on what exactly to eat, macronutrient counting (the concept behind IIFYM) gives more specific guidelines on amounts and types of foods you should be eating to meet your goals,” says Dr. Jaime Schehr, an expert in integrative and sports nutrition and owner of xFitLab and Schehr Nutrition. Sounds good so far, right? The macronutrients involved in IIFYM will be familiar to anyone who already reads food labels on the reg: protein, fat and — everyone’s favorite — carbohydrates. Basically, the diet revolves around making sure you eat the correct proportions of these three macronutrients in order to optimize nutrition. Figuring out the correct proportions of macros for your body and goals can be complicated. Luckily, there are online calculators that can help you figure it out based on your current weight, whether or not you want to lose weight, gain muscle or improve your overall body composition (meaning exchanging fat for muscle). If that sounds a little overwhelming, “a nutritionist will absolutely be able to guide you on this,” adds Dr. Schehr.


Why is it so popular right now?

One of the biggest pluses of this eating style is also one of its biggest minuses. “IIFYM is considered a flexible diet since you can essentially eat anything you want (aka pizza, fries and pies, oh my!) as long as it fits your macros,” explains Jackie Arnett Elnahar RD, Esq. So theoretically, you could still achieve your goal while still eating the junk food you love. Aside from not having to say goodbye to your favorite foods, many people love that IIFYM’s guidelines can make it simpler to figure out what you should eat and how much of it. “Macronutrient counting ultimately still considers calories in and calories out as the means by which the body gains or loses weight, but creates a more clear road map of how to reach that goal,” says Dr. Schehr. Essentially, if you hate counting calories but want to be conscious of how much you’re eating and what kinds of nutrients you’re eating, IIFYM could make a lot of sense for you.

Additionally, this diet fits in really well with the current emphasis on fitness and wellness in general. “IIFYM is not a new concept,” Dr. Schehr notes. “As a matter of fact, sports nutritionists have been using macronutrient counting for years, and some existing, well-known diets used this same concept under different names, like the Zone Diet. More recently, with the rapid growth of the fitness scene and the incredible expansion of specific sport-like studios, like CrossFit and cycling, everyday exercisers are now working out like athletes. Thus, the tools that athletes use for training, such as macronutrient counting, have gained popularity amongst the general population.” Makes a lot of sense, if you ask us.

Who does it work for?

So who can actually benefit from this way of meal planning? Pretty much everyone, according to both Elnahar and Dr. Schehr, but there are a few caveats. “Because IIFYM is dependent on calculating the amount of what you’re eating, you need to be willing to put the time in to make sure you are meeting your quota and calculating portion sizes properly,” explains Elnahar. “Hence, this diet is more popular among people who are more strict and able to do more extraneous tasks in dieting.” Additionally, Dr. Schehr notes that for vegans, IIFYM can be less than ideal. “A lot of their protein sources are also carbohydrate sources, so this diet can be confusing or not specific enough,” she says.

On the upside, “IIFYM is a very reasonable diet plan for someone looking for guidance on weight loss, increasing lean muscle mass or wanting better control of how much they eat,” says Dr. Schehr. “Because IIFYM does not restrict a person from any type of food, it can be easier for someone following this diet to find their diet-specific foods no matter where they are, especially when compared to something like Whole30, which is very specific on what you can and cannot eat.” If you opt for IIFYM and choose to eat lots of junk food, though, you’ll miss out on that fresh, alert and totally detoxed feeling Whole30 aficionados report.


How does it affect your fitness goals?

Because IIFYM has its origins in the body-building scene, it makes sense that it would be ideal for those who are trying to achieve major fitness goals — especially in the weight room. “IIFYM can be helpful to workouts since you won’t be adding more calories to your diet than needed,” says Elnahar. “The body will have less glycogen stores and will burn fat more effectively.” One thing to note here, though, is that if you’re expending energy exercising, you need to make up for that with additional macros. As with many other diets, when you work out, you get to eat more! “When done correctly, IIFYM can really improve both sports performance and recovery,” says Dr. Schehr. “The thing most important to keep in mind is that each sport is different and your diet may need to be adjusted for that. If someone is following IIFYM in their ‘offseason,’ the plan may be very different than what they need in season.”


Here’s the bottom line.

“We must first remember that all diets ultimately deliver the same basic message: Eat more vegetables, control your portions and increase your activity level,” Dr. Schehr points out. “Whole30, Zone, Paleo, IIFYM and even Ketogenic all emphasize an increased non-starchy vegetable intake, portion control in specific areas and the importance of fiber.” So yeah, the diet works if you stick to it, just like most diets out there. “As long as you calculate your calorie needs properly and measure your calories and macronutrients in an accurate fashion, you can certainly lose weight and improve body composition,” says Elnahar. “However, since you may be eating foods that are less ‘clean,’ this can ultimately affect mitochondria function, which is important for energy in our bodies. With that, the IIFYM diet is a good short-term solution but not the best long-term lifestyle solution to healthy eating. The benefit of IIFYM is that it is an efficient, mathematical way to lose weight while getting the appropriate carbohydrates, fats and proteins needed for homeostasis — but unfortunately, without regard to the quality of the foods.”

In other words, if you’re the kind of person who likes to measure things out, have a plan that’s tailored to your specific objectives, know exactly what you’re putting in your body, and occasionally splurge on things (pizza, cookies and cake!) while still meeting your fitness goals, IIFYM could be the right solution for you.

Have you ever tried IIFYM? How did you make it work? Tweet us @BritandCo and let us know!

(Photos via Getty)