What Macros Are Right for Weight Loss?

By: Allison Knott, MS, RD, CSSD

If you've moved beyond counting calories to counting macros for weight loss, use this guide to find the right numbers and percentages for your goals.

Pictured Recipe: Spring Roll Salad

"Macros" is a buzzword that was likely never heard outside of a nutrition science classroom until just a few years ago. Today, the abbreviation macros (short for macronutrients) is splashed on Instagram profiles and the covers of books. This begs the question: what are macros and should you be counting them in your diet?

Read More: Macros Diet Meal Plan

What Are Macros or Macronutrients?

"Macronutrients are the compounds that provide us with energy, and they are split into three categories: proteins, fats and carbohydrates," says Carolyn Brown, M.S., R.D., a nutritionist at Foodtrainers, a private nutrition practice in New York City.

However, you can't survive on a single macronutrient alone. That is a good thing, because most foods have a combination of the three.

"Each one provides your body with different functions," Brown says. "For example, carbohydrates are our primary, immediate energy source. Protein repairs and regenerates tissues and cells, and fats are essential for healthy brain function."

Understanding the functions of macronutrients helps to better explain why eating a variety of foods is important for optimal health. However, it doesn't answer the question of how much of each macronutrient is needed per day and how much is needed if you want to lose weight. Those answers aren't as straightforward as many would like them to be.

Consider the rise of the low-fat craze in the '90s. Many people started restricting the macronutrient thought to contribute to weight gain, fat.

Fast forward to today, and fat has made a comeback to the point that many are following the exact opposite diet and severely limiting a different macronutrient, carbohydrates.

This swing back and forth has spurred a legitimate question: for weight loss, which is better, low-fat or low-carb? The debate continues, and recommendations differ among health and wellness professionals.


Carbohydrates provide 4 calories per gram and are found in starchy foods and grains like bread and rice, fruits, dairy and sugar. They are an important source of energy and fuel in the body.


Proteins deliver 4 calories per gram and are found in dietary sources like meat, fish, dairy, eggs, nuts, seeds and legumes. Protein is made up of amino acids, which are the building blocks for protein and help make muscle and tissue in the body.


Fat contains 9 calories per gram and is important to help your body absorb the fat-soluble vitamins A, D, E and K. While fat has a bad reputation and is higher in calories, it is important to include healthy fat in your diet, and fat is a very satisfying macronutrient.

Read More: The Best Dinner Foods for Weight Loss


Pictured Recipe: Creamy Fettuccine with Brussels Sprouts & Mushrooms

Which Macro Is Most Important for Weight Loss?

Many who use macronutrients as a means for losing weight will wonder if it's better to follow a low-carbohydrate or low-fat plan for weight loss. Recent research shows that it may not matter which plan you follow. Instead, it comes back to the basics of calorie restriction.

"Total daily calorie deficit takes precedent over macronutrient distribution in the hierarchy of needs when it comes to weight loss," explains Tony Stephan, R.D., a personal trainer and owner of Tony Stephan Fitness & Nutrition.

However, that doesn't mean that macronutrients, especially in the context of diet quality, don't play some role in the goal to lose weight.

"Having a dialed-in macronutrient ratio will yield better performance outcomes. If you eat in a calorie deficit, but only eat Twinkies all day, you may lose weight, but I doubt you will feel your best," Stephan says.

In other words, it isn't just about calories. The macronutrient distribution does matter for both weight loss and total health, and the types of each food you eat matter too. After all, carbohydrates include everything from candy to whole grains, and those foods provide vastly different nutrients.

The same goes for the type of fat. Research has shown that it isn't the total fat lumped together that needs to be limited, but, instead, it is certain types of fat. Considering this, choosing low-fat versus low-carb comes down to choosing a pattern of eating that you can sustain—and that will provide adequate nutrients while helping you meet your goals.

Read More: What Does a Healthy Serving of Carbs Look Like?

Can Counting Macros Help with Weight Loss?


Pictured Recipe: Salmon & Avocado Poke Bowl

It could, but many dietitians and health professionals take a different approach to helping individuals lose weight. The National Institutes of Health recommends 45-65 percent of calories come from carbohydrates, 20-35 percent of calories come from fat and 10-35 percent of calories come from protein.

Stephan recommends starting by tracking intake for a minimum of seven days to determine your energy needs. "If you have been eating the same way for the last month or so, and you are not losing weight, it's safe to say that your current daily calorie total is your maintenance calories," Stephan explains.

From there, Stephan adjusts macronutrients based on preference and activity level. First, he sets the protein amount and then fills in the carbohydrate and fat amounts according to personal preference. "If I have an active individual, I tend to give more of an abundance from carbs. I believe personal preference should dictate [fat and carb amounts] with my clients," he says.

But this type of approach may not be sustainable for some and could even trigger unhealthy eating behaviors. "When a client comes in attempting to lose weight, as most do, I never point them to a specific number of macros or an app direction," Brown says. "Fixating on strict numbers, weighing food, logging calories—it all tends to lead to obsessive eating and 'falling off the wagon' or breaking their diet, and a cycle of this over and over," she says.

What to do instead? "I suggest focusing on nutrient density. Eat real, unprocessed foods that mostly do not have labels at all, and you do not have to drive yourself crazy over numbers," Brown explains.

Read More: Best & Worst Foods to Satisfy Hunger

A Word on "If It Fits Your Macros" (IIFYM)


Pictured Recipe: Spaghetti Squash Lasagna with Broccolini

It you've spent any time following the conversation around macronutrients, you've likely come across the acronym IIFYM. IIFYM stands for "If It Fits Your Macros" and originated in body-building circles, according to Stephan. "It was the acronym that answered the universal question of 'Can I eat X, Y or Z food and still see results?'" he says. Stephan explains that IIFYM, at its core, means no foods are off-limits as long as total daily calories are controlled and macronutrients are distributed properly for the end user's goal.

However, he cautions that this doesn't mean that the types of foods that fit into the macronutrient count and their quality should be ignored. "There should not be a dichotomy when it comes to food quantity and food quality. I am never going to tell my client that they can't have their favorite foods, but I do set protein goals, fiber goals and water goals daily for them to achieve," he says.

Brown agrees, saying that IIFYM is reminiscent of other point-based systems. She finds it worrisome because counting macronutrients has the potential to take the focus off food quality. "Someone could eat all their points in, say, a brownie, or another food with zero nutrient density, and miss out completely on all the vitamins, minerals, phytonutrients and energy. That's not to mention volume and satiation, which is provided from [for example] a whole meal with vegetables, fish, olive oil and quinoa," Brown says.

As with any diet that focuses on nutrients in isolation and views foods as simply numbers and not for their quality, there is a risk of building a diet around foods that may fit the macro count but not provide health benefits.

"Quality is the No. 1 essential for long-term weight loss," Brown stress.

Stephan agrees, "How can you achieve 35 grams of fiber per day eating ice cream all day? You can't. No foods should be off-limits but, like anything else, it's about balance."

Try These: Healthy High-Fiber Recipes


Pictured Recipe: Chickpea & Quinoa Buddha Bowl

Bottom Line

No matter the approach, the message is the same: your diet has to be sustainable.

"My goals with clients are always to help them incorporate healthier eating into their lives and to learn flexibility, how to socialize and feel normal, but also feel great about their food choices," Brown explains. Counting macros, she explains, rarely fits into that approach.

"The clients I've had use macros have historically felt overly restricted and completely reliant on homemade food, which is fine for a week or two, but not realistic long-term," she says.

Research does show that it is a pattern of eating over time that makes the difference in long-term health. "Someone should always ask, 'Can I do this for the rest of my life?' before beginning a protocol. If they can't say yes, the likelihood for long-term success is very minimal," Stephan says.

Watch: How to Make Healthy Meals That Swap Carbs for Veggies


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