Maybe you’ve overheard people at the gym buzzing about how the IIFYM diet helped them slim down. Or at a work lunch, some coworkers made references to counting “macros” rather than calculating calories or carbs.
What’s it all about? The initials stand for “if it Fits Your Macros,” an acronym that caught on first with bodybuilders, who used this healthy eating program as a way to stay fit for competition. Now, the approach has gone mainstream and is super popular with regular people as well.
Supporters say that counting macros helps them reduce their weight and body-fat level without obsessing over calories or the number on the scale, all the while allowing for treats and other fun foods at will. Even people who aren’t looking to lose weight believe that the approach helps them eat nutritiously but with flexibility, and that allows them to maintain a healthy weight.
Counting macros is trendy and has real science behind it. Still, it’s not a perfect strategy for everyone looking to shed pounds, and amid all the buzz about IIFYM, it has a few drawbacks that don’t get the attention they should.
Here’s everything beginners need to know about the macros diet—plus up-to-date information for people who use the program already but would like to get a better understanding of how to calculate macros and make smart, healthy food choices.
What are macros?
The macros diet “is a flexible approach to eating healthy while still enjoying the foods that are delicious to you,’ says Arizona–based sports nutritionist Paul Salter, MS, RD, CSCS.
But first, it’s important to know what macros are. The term stands for macronutrients, and it refers to the three macronutrients that should be part of any healthy eating program: protein, carbohydrates, and fat. (Micronutrients, on the other hand, refer to vitamins and minerals.) If you’re following the macros diet, you’re keeping track of these three macros, aiming to eat a set amount of each based on your goals and your taste buds throughout the day.
Counting macros offers a lot of options, because every food falls into at least one of these categories—and that means no food is off limits. You can enjoy what you’re in the mood to eat, and you don’t need to feel guilty over a splurge or treat as long as you hit your macros target for the day.
Why the macros diet is different
One reason comes down to the food flexibility mentioned earlier. Traditional diets, from low-carb plans to juice fasts, often fail because “restrictive approaches are not sustainable,” says Salter. When a dieter is asked to eliminate specific foods or entire food groups, deprivation sets in, he explains. If a diet requires that you give up sugar, for example, or an occasional burger is banned, you may throw your hands up and call it quits, and then regain weight quickly. It can also lead to an unhealthy relationship with food and the scale, adds Salter.
On the other hand, the macros diet teaches you about the impact each macronutrient has on your body, and you learn how food makes you feel. You look at foods for what they are, which is fuel for your body and health, and learn about their nutritional content instead of obsessing over calories. The “it” in “if it fits your macros” is a food option; your macros is shorthand for the total number you need to consume daily to fit your diet or nutritional goals.
Macro counting also represents a mind shift. Rather than thinking about how you need to stay under a certain number of calories (which can feel restrictive and cause that sense of deprivation to set in), you’re aiming to eat the right amount of protein, fat, and carbs. It’s also designed to be customizable depending on your goals. “I love to get people on flexible dieting because it’s empowering,” says Lauren Irick, a certified personal trainer, fitnessnutrition specialist, and IFBB pro bikini competitor.
How counting macros helps with weight loss
Focusing on the three macros—protein, carbs, and fat—lets you take advantage of the way foods in each category optimize weight loss. Foods high in protein, for example, slows digestion so you can stay fuller longer. Protein is also critical for muscle growth and repair. “The more muscle you have, the more calories you burn,” says Salter. “You can eat more and still lose weight.”
Fat plays a crucial role in staying slim too, especially when it comes to feeling satiated. Foods high in fat put the brakes on digestion, making you more likely to eat slower and feel full faster. They also boost the satisfaction factor of your meal, so you can walk away from the table feeling fulfilled, not deprived.
Though carbs have gotten a bad reputation thanks to popular high-protein diets like The Atkins Diet, the right kind of carbs are encouraged in the IIFYM diet approach. Foods high in complex carbs—think a sweet potato, oatmeal, or quinoa—break down in your body slowly, keeping your energy and blood sugar levels at an even keel. “Carbs are the prime energy source for your brain, muscles, nervous system, and heart,” says Salter. “If you’re active, err on the side of a pretty high amount of carbs.”
Irick says she often sees active female clients who are intentionally undereating carbs, and as a result don’t have the fuel to get though a workout. The reason fitness-oriented people like the IIMYM plan is because it’s all about eating well to feel good and have plenty of energy and focus. Skimping on carbs can keep that from happening, she says.
How to calculate your macros
First, start with an online calorie calculator. (You’re not going to count calories, but this will help you figure out your macros). The calculator you use should ask for factors like your age, gender, activity level, and goal weight (or your current weight, if you’re trying to maintain it). It will estimate how many calories you need in a day to hit your target. “It’s not set in stone, but it’s a starting point,” says Salter.
To lose weight, lower your usual daily calorie intake by 100 to 250 calories, suggests Irick. That may not sound like a lot, but this way you can adjust to macro counting, give it time to work, and see a downward trend in your weight. “I am pretty conservative because for me as a coach, the goal is to keep you eating as much as possible while still seeing progress,” she says. Plus, if you reduce it too much, it’s hard to go any lower and adjust as needed when your weight loss hits a plateau.
Next, Salter suggests aiming for a number of grams of protein per day that’s equal to your weight in pounds. So a 140-pound woman should set her protein goal at 140 grams per day. You’ll notice that’s far more than the RDA of 0.36 grams per pound of body weight. In the latter scenario, a 140-pound woman would need about 50 grams of protein daily. Given protein’s important role in weight loss, you’ll want to consume more of it.
Then, fat and carb numbers will totally depend on your goals and taste preferences. Let’s say your calorie goal is 2000 calories per day. One gram of protein supplies four calories. If you’re eating 140 grams of protein, you’re getting 560 calories from protein. You have 1440 calories remaining to split between fat and carbs.
One gram of carbohydrate also supplies four calories, and one gram of fat contains nine calories. From there, you do the math (aka, count your macros). “You plug in and adjust the number of grams of fat and carbs that meets your taste and energy preference,” says Salter. For example, a healthy plate can be broken up as a four-ounce serving of protein, one to two cups of vegetables, one-half to one cup whole grains, and one to two tablespoons of fat via butter, salt, or salad dressing, adds Irick.
Counting macros is a trial and error process, and it can take time before you arrive at a macros combo that works best for you. You’ll know you’ve found it when you feel good, have energy, can tackle your workout, and you start to move toward your weight loss goals at the healthy rate of 1-2 pounds per week on average.
Healthy, macros-friendly foods to focus on
The IIFYM plan is a flexible style of dieting, but you still need to opt for nutritious choices to make it work for you. “You may be focused on macronutrients, but micronutrients like vitamins and minerals matter, too,” says Irick. When designing your ideal plate, you want to gravitate toward fresh, whole foods to get a wide range of nutrients you need. Here’s how the experts suggest breaking it down:
Protein. Ideally, fish, seafood, and eggs, plus lean chicken, pork, beef, and lamb in moderate amounts. Make sure you evenly distribute your protein intake throughout your daily meals and snacks, both for satiety benefits and to maximize muscle synthesis.
Fat. Eat most of your fat from unsaturated sources rather than saturated or trans fat foods. Avocado, nuts, nut butter, olive oil, and seeds are all smart options.
Carbs. Go for complex-carb, high-fiber picks, which many people fall short on yet goes a long way in keeping you full, says Irick. That means whole grains like farro, oats, and brown rice, as well as fruits and veggies. Steer clear of processed carbs and simple-carb treats like donuts and cookies. They’re allowed with the IIFYM approach, but if you load up on junky carbs that cause your energy level and appetite to fluctuate wildly, you’ll find it difficult to stick to the program.
Water. H20 is so important, Salter calls this the fourth macronutrient. Rather than aiming for a certain number of ounces, pay attention to your urine. You want your pee to look like light lemonade. If it’s darker, drink a glass of water. If it’s completely clear, you may be overhydrated.
How to enjoy treats and still lose weight
These are the not-exactly-nutritious foods that you generally eat for enjoyment, like ice cream, candy, fried foods, and fast food. (Other diets might call these “cheats,” but since no food is off limits in the macros diet, eating them doesn’t mean you’re cheating on anything.) The frequency you add them into your diet all depends on your goals.
If you’re in the first 10 to 14 weeks of trying to lose weight, you want to really limit these foods, particularly because you may find it hard to stop eating them once you start, says Salter. If you’re in a weight maintenance phase, you have more leeway, and the key is to find the right amount for you, whether that’s once or twice a week or once a day.
Above all else, remember: “This is an approach that promotes the inclusion of treats, but it’s not the foundation. The primary focus is on protein, healthy fat, and lots of fruits and vegetables,” says Salter.
Food prep tips to help you count your macros
When making macro nutrition choices, it’s helpful to think about your daily goals like a bank account. “You get to choose how you spend your macro money,” says Irick. That said, some people find the most success by planning out their entire week and following a meal plan, while others fly by the seat of their pants and pick healthy varieties of what they’re craving at the moment.
The benefit of the former is that you don’t have to constantly make decisions about what you’ll eat throughout the day. The benefit to the latter is that you can eat based on your tastes, and then adjust as necessary as you go about your day. For example, if you don’t have any fat left at dinner but need protein, you can pick out a fillet of fish and add a pile of veggies to your plate.
A third option is to prepare many different foods so you can have them at the ready throughout the week to fit your macros for each day. Salter likes this approach and generally recommends prepping two or three different carbs, two or three proteins, and keeping ample fresh or frozen fruits and veggies on hand. “It’s time-savvy and keeps you prepared for success, so there’s no excuses,” he says.
The downsides of calculating macros
As with any trendy diet plan, the macros diet has many believers—and sometimes their claims of how easy it is or how much weight they lost should be taken with a grain of salt. Diane Boyd, RD, a sports nutritionist in private practice in Wilmington, North Carolina, cautions people not to get sucked into any huge promises, particularly that you can burn fat while eating what you want if you count macros. “That’s not science—it’s an oversimplification,” Boyd says.
Counting macros also can make people feel that just doing the calculations and staying within their limit is enough. But just because you hit your macro goals doesn’t mean you have a healthy diet. “You could potentially not eat a veggie the entire day or eat only saturated fats and still meet your macros,” says Boyd. You can dodge this trap by not focusing only on these numbers and instead include many nutritious sources of protein, fats, and carbs in each meal.
Another issue many people have with the IIFYM plan is that it “doesn’t address the behavioral aspects of eating or overeating,” says Boyd. If you find that emotional eating is a problem for you, simply going on a macro plan won’t answer the reasons why or help you work through them. The approach can be “too black and white. People say, ‘it doesn’t matter as long as IIFYM,’ but there are a lot of other variables in eating well and they are important,” she says.
Counting macros for the long-term
If you give the IIFYM plan a try, you might hit some road blocks along the way. But it can work for you as long as you plan accordingly and choose nutritious foods the majority of the time.
And of course, adjust your macros and what you put on your plate as needed. You’ll also be more successful if you reach out when you need help maximizing your ratios. An RD who is familiar with the macros diet or a fitness professional who coaches people on the concept can be a big help, says Irick.
“This is not a linear process,” says Irick. “But that’s great, because it’s a learning process. You’ll start to understand what works the best for you and your body,” she says. You also likely won’t be on the same plan or macros forever. “Our bodies are constantly adjusting, so a set macro meal plan won’t work forever,” Irick says. The beauty of IIFYM, she notes, is that you can manipulate the macro numbers as your body and goals change.