Jun 7, 2018
Meeting in the Middle
Gillean Barkyoumb

An athlete comes to you with an outstretched arm holding a smartphone. On the screen, you see an Instagram feed of sculpted physiques lifting weights intermingled with pictures of pancakes dripping in syrup, loaded slices of pizza, and sticky-sweet donuts. Under each photo, you notice #IIFYM. “I want to try this,” your athlete says. But what exactly is “this,” and will it truly help them?

Getting a lot of play on social media, IIFYM stands for the If It Fits Your Macros diet, also known as flexible dieting. It’s a fueling trend that first gained popularity among CrossFit athletes and bodybuilders, and it’s slowly making its way into the athlete mainstream.

In its most basic form, flexible dieting focuses on how much an individual eats as opposed to what they eat. But rather than focusing solely on total calorie intake as many traditional diets do, flexible dieting tracks consumed grams of the macronutrients — protein, carbohydrates, and fat.

Athletes following IIFYM create a diet that provides the right amount of protein, carbs, and fat (macros) for their personal needs based on their gender, height, weight, activity level, and fueling goals. Think of IIFYM as having a nutrition budget. As long as athletes reach their daily allotment of macros, they should be able to meet their respective body composition or performance ideals.

One of the most popular, yet controversial, features about following flexible dieting is the idea that athletes should be able to enjoy any food they want. It is based on the theory that a calorie is a calorie, no matter the source. So under this plan, a donut or brownie is more than okay, just as long as the athlete accounts for it in their total macro intake for the day.

Because of this, detractors of flexible dieting say it doesn’t place enough emphasis on food quality. There’s also a concern that IIFYM focuses too much on macros while neglecting other vital nutrients. However, proponents of the plan say when done right, IIFYM provides a solid balance of moderation and flexibility.

Here are the benefits:

Balanced macronutrient intake: Perhaps the biggest advantage of following IIFYM over other fueling plans is that it accounts for all three macronutrients. Many fad diets reduce or eliminate a macronutrient (think low fat, low carb, etc.), leaving the athlete feeling deprived and often leading to overindulgence. While these diets may work for the short-term, they are not realistic lifelong eating routines and can be especially harmful to athletes who push their bodies on a daily basis.

IIFYM is better than simply counting calories for the same reason. An athlete may think they are fueling optimally if they stay under a set number of calories per day, but it’s easy to miss out on one or more of the macronutrients in the quest to reach a daily calorie goal.

Customized diet plan: Flexible dieting provides a way to create personalized nutrition regimens around individual training styles and performance goals. Athletes are more aware of what they are eating and how they can tweak their diet to maximize their output. So they have the option to increase carbohydrate intake if they feel fatigued at practice or boost carbs and protein if they’re sore the morning after a tournament.

IIFYM can also easily be altered throughout different training times of the year to keep athletes in their best shape. For instance, they may want to decrease the amount of carbohydrates consumed in the offseason because they are no longer having multi-hour long practices. Instead, they could raise protein consumption to better take advantage of weight training.

Other fad diets often don’t allow for this level of customization. Think of athletes following a low-carb or low-fat plan. They usually have to adjust their fueling to fit the parameters of the diet, rather than the diet working to accommodate their needs.

Flexibility: We all know that high school and college athletes aren’t going to eat at the dining hall or freshly prepare their own meals every day — there will be dinners at the local pizza place, movie nights with friends, or a Saturday brunch. IIFYM allows athletes to engage in these activities and eat the foods they enjoy in moderation without falling off their diet plan or experiencing guilt. This may keep athletes on track for the long term rather than throwing in the towel when cravings hit. Traditional models of fueling for performance don’t always offer this level of flexibility.

Accountability: That being said, IIFYM doesn’t give athletes leave to go totally off the rails with their diet. Rather, it holds them accountable for what they choose to eat. High school and college-aged athletes often have diets lacking in key nutrients due to poor access to quality foods, budget restrictions, and nutrition misconceptions. With IIFYM, their subpar food choices will show up in their daily intake, and they will have to adjust accordingly. For example, an athlete can enjoy a carb-heavy stack of pancakes at Saturday brunch, but then they must tweak their carb consumption for the rest of the day to make sure they don’t exceed their total macro budget.

In addition, by tracking their intake, athletes can start to see how diet affects performance. Before trying IIFYM, a soccer player may think they are getting enough carbs to fuel their games. However, when they actually record their macros with IIFYM, they may notice they are nowhere near what’s recommended for optimal performance.

Body composition goals: IIFYM has become a favorite for athletes looking to gain muscle or lose fat because it ensures proper macronutrient balance and allows for individualization. For instance, IIFYM can work for both a freshman football player wanting to put on weight and a seasoned cross-country runner seeking to cut body fat. While both will follow the principles of flexible dieting, their intakes will be extremely different. The football player will have a bigger budget of macronutrients with more carbohydrates and fats, and the cross-country runner will have a smaller budget and will need to be stricter with food choices. (See the case studies below for more on how to use IIFYM to meet body composition goals.)

Flexible dieting has become especially popular with athletes looking to lose fat because it doesn’t require them to deprive themselves to meet their goal. In this way, it can be a better option than simple calorie restriction, which can include strict calorie counts, approved food lists, and complete elimination of food groups. Further, workouts and overall energy levels can suffer on calorie restriction. Athletes who’ve had results losing fat on IIFYM say it allowed them to maintain high energy levels and continue to train hard.

Next week, we’ll talk about the potential drawbacks of IIFYM.

Image by Jack and Jason’s Pancakes

Gillean Barkyoumb, MS, RD, is a nutritionist based out of Gilbert, Ariz., and the creator of MillennialNutrition.com, a site dedicated to exploring the shift in today's food culture.

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