For some people, the diet plan itself seems rigid, even though it’s praised for its flexibility. But for others who swear by it, IIFYM is the only thing that allows them to eat a variety of foods and drop pounds at the same time.
So, if you want to give it a shot, here’s everything you should know about what flexible dieting really means, how to count your macros, and exactly what to keep in mind to make it work for your goals.
What Is the IIFYM Eating Plan?
“The overall concept is similar to Weight Watchers in that you can eat what you want as long as you’re keeping your calories at a certain level, but with flexible dieting there’s an emphasis on protein,” says Brad Schoenfeld, Ph.D., director of the Human Performance Lab at CUNY Lehman College in New York.
There are three macronutrients that make up every bite of food you eat: protein, carbohydrates, and fat. While a majority of foods contain all of these macronutrients, most skew heavily toward one or two of them.
For instance, meat is loaded with protein, bread is mostly carbohydrates, and olive oil is predominantly fat. Your body needs all three in some capacity to function to its fullest potential.
When you burn more calories than you take in, while simultaneously rebalancing your diet to hit certain macronutrient targets, you’ll lose weight while eating whatever foods you enjoy. Or at least, that’s the pitch from some popular IIFYM sites and blogs.
How Protein Becomes Muscle:
Can You Really Eat Anything You Want?
While experts agree a focus on calorie caps and macronutrients can be beneficial, and that strict adherence to a “clean foods” diet isn’t necessary, they also take issue with some aspects of the IIFYM ideology.
“I’m a proponent of flexible dieting, and I think it’s the most practical approach to weight maintenance, but I think the concept has been bastardized a little bit,” Schoenfeld says. “Some people have oversimplified it and said you can eat Pop Tarts or cheese doodles for your carbohydrates as long as you’re hitting your macros, and I don’t agree with that.”
The foods you eat still matter, Schoenfeld emphasizes. A vegetable, which is full of disease-fighting antioxidants and filling fiber, will always be better for you than a cheese doodle, which is essentially empty calories.
The thing is, finding a balance between the two is part of what makes IIFYM effective. If you eat mostly unprocessed whole foods, you don’t have to beat yourself up about indulging in those not-so-great for your options occasionally, Schoenfeld says.
Other experts agree. “I think focusing on the right balance of protein and carbs and fat while allowing yourself some freedom to eat candy or fun foods now and then is a good approach,” says Stella Volpe, Ph.D., chair of nutrition sciences at Drexel University in Philadelphia.
“The quality of your diet is still one of the most important factors, but our diets don’t have to be so rigid to be healthy,” she adds.
That means you have the liberty to eat the foods you want, as long as they’re predominately nutrient-dense options. Consistently eating large amounts of fast food and processed snacks just because it “fits your macros” isn’t necessarily sustainable when you look at the bigger picture of what it means to eat for your health. (In need of delicious and healthy meal ideas? Check out the Metashred Diet from Men’s Health. It’s full of recipes that will help you reach your fitness goals.)
How Do You Calculate Your Macros, Anyway?
To calculate your macros, you’ll need to do some math. Here are four simple steps you can take to find the ratio that works best for you.
Step 1: You need to find out your “energy balance,” or the number of calories you take in and burn each day, Schoenfeld says. There are lots of great apps, like My Fitness Pal, that will do this for you, Volpe says.
Step 2: Once you have those figures, you need to come up with a target calorie intake to meet your weight goals. If you’re looking to lose weight, you need the number of calories you consume to be 10 to 15 percent below what you’re expending each day, Schoenfeld says.
If you’re looking to maintain your weight or gain weight, adjust your calories accordingly.
Step 3: Aim to eat roughly one gram of protein per pound of body weight. (For reference, one 3 ounce serving of bottom round beef contains nearly 30 grams of protein.) “The scientific literature is very clear that getting proper amounts of protein is the most important thing to maximize muscle and improve body composition,” Schoenfeld says.
While this one-gram-per-pound protein goal is crucial, its ratio to fats and carbs will be different for everyone.
“There is no ideal ratio,” Schoenfeld says, contradicting many IIFYM sites and blogs that argue a strict 40 percent protein, 40 percent carbohydrate, 20 percent fat split is optimal for your health. “Some people do well on lower-carb plans, and some people do well on lower fat,” he explains. “It all depends on the individual.”
One gram of protein contains about four calories. If you’re a 200-pound man, that means your goal would be to eat 200 grams of protein each day, contributing roughly 800 calories to your total. So if you’re an average active guy that needs 2,800 calories a day, protein would make up roughly 30 percent of your total macronutrient ratio.
Fats and carbs—which contain nine and four calories per gram, respectively—will make up the 70 percent of calories you have leftover for your daily target. Figuring out the breakdown for those will be up to you and how your body responds to them.
Step 4: Use an app like My Fitness Pal or Lose It to figure out how to divvy up your carb and fat intakes based on your diet goals. Also, by inputing the foods you want to eat, you can see their macro makeup and figure out how to incorporate them to hit your diet targets, Schoenfeld says. Using the IIFYM macro calculator is also a good start if you’re completely unfamiliar with the diet.
Again, he says, there is no ideal or universal ratio that will work for everyone.
How Can You Make Your Macros Work For Your Goals?
First, understand that you should give yourself some wiggle room. Both Schoenfeld and Volpe advocate an “80-20” approach to your diet.
“That means 80 percent of the time, you want to be making healthy food choices,” Volpe explains. The other 20 percent, feel free to eat what you want—provided you’re also hitting your macros and calorie targets.
Your workouts will also make a difference. If you’re an athlete or in training, you’ll want to incorporate more carbohydrates into your macros, Volpe says.
“You need to replenish that glycogen your muscles are using during exercise,” she explains, since glycogen is the energy that powers you during a workout. “I work with a lot of athletes—including weight lifters—who are nervous to move toward higher carbohydrate diets, but they’re amazed at how much better they perform and feel.”
If you’re looking to lose weight, emphasizing healthy fats, like avocados and nuts, may make sense. “Fats are very satiating,” Volpe says. There’s also evidence that consuming healthy fats switches off your body’s fat-storage processes.
Now, this all may sound like a lot of work, but it doesn’t have to be. In fact, when you think about diets that eliminate whole food groups or prescribe complicated and specific food combinations, IIFYM can seem more relaxed.
“Adherence is the most important thing for any diet to be successful, and we know people don’t stick with these restrictive diets,” Schoenfeld says. “Flexible diets allow you to lose weight or have success while eating a much wider range of foods.”