You probably know that exercise alone isn’t enough to gain muscle and lose fat.

And that, ultimately, your success or failure is going to be decided by your diet.

Think of it like this:

If your body were a car, exercise is the gas pedal and diet is the fuel in the tank.

You have to step on the gas (exercise) to get moving (improve your body composition)…

…but how far will you get without enough of the right fuel?

My point is this:

  • If you know how to manage your diet properly, building muscle and burning fat will be easy and straightforward.
  • If you don’t, it will be ridiculously difficult …if not impossible.

And if you’re like most people, you probably fall in the latter camp.

It’s a shame that so many people are getting it wrong, too, because it really is easy to get right.

The problem, though, is the sheer amount of conflicting information out there on how to get fit. Books, blogs, and magazines abound, but finding something that actually works as promised is like hunting for the proverbial needle in the haystack.

At this point, you may even be wondering if anything really works…and I understand!

Things are about to look up, though, because this article is going to put you on the fast track to success.

By the end, you’re going to understand the simplest, most effective way to eat to gain muscle and strength and get healthy:

Macronutrient-based dieting (which is also called “flexible dieting”).

With it, you absolutely can get the body you want and you don’t have to…

  • starve yourself,
  • struggle with food restrictions,
  • eat at set meal times,
  • suffer from low-carb misery,
  • waste energy fighting your cravings.

Ready to learn how?

Read on.

The Macronutrient Calculator

This is a good goal for people with a lot of weight to lose, but not for people who are slightly overweight or who are lean and looking to get leaner.

Dietary Preferences

Calories 1,679
Protein 168 g/day
Carbs 126 g/day
Fat 56 g/day
Calories 1,679


If you’re an experienced flexible dieter and just need a calculator, you’re ready to go.

If you want to learn more about “macros” and how to use this calculator to make meal plans that actually work, then keep reading.

What are Macronutrients?

The nutrients that we need in relatively large amounts are called macronutrients.

Most people think of “macros” as just protein, carbs and fat, but technically the term also includes minerals like calcium, zinc, iron, magnesium and phosphorous.

But for the purposes of this article–diet and meal planning–we’re going to be focusing on protein, carbs and fat.

The Simple Science of Macronutrient Dieting

rules for cutting bodybuilding

If you’ve browsed the Instagram fitness scene, you’ve undoubtedly seen it:

Shredded guys and gals sharing pictures of stacks of pancakes or giant bowls of Rocky Road ice cream or some other “sinful” indulgence.

And you’ve probably wondered what the heck was going on.

They can’t possibly eat like that and have rippling six packs, can they? That was like the one cheat meal for the month or something, right?

Lo and behold…these people really do eat that stuff. And a lot more frequently than you might think.

The reason they can “get away” with it is this:

When it comes to body composition, what you eat doesn’t matter nearly as much as how much you eat of it.

That is, the number of calories we eat and how those calories break down into protein, carbs, and fats has more impact on our physiques than our choicest of foods and when we eat them.

 Read: How to Measure and Improve Your Body Composition

Let’s take a closer look at how this works… 

Yes, Calories Count, and Here’s Why…

The relationship between the energy you consume and the energy you use is referred to as “energy balance.”

The unit of measurement we use to discuss energy balance is the calorie, which is the amount of energy required to heat one kilogram of water one degree Celsius.

Energy balance is a vital concept to understand because it alone determines how your body weight changes in response to the food you eat (and thus how many calories you should be eating depending on your goals).

You see, if we look beyond the magazine shelves and pill and powder hucksters to the scientific literature, we quickly learn two things:

  • You have to burn more energy than you consume to achieve meaningful weight loss.
  • You have to consume more energy than you burn to achieve meaningful weight gain (both fat and muscle).

Now, if you’re tempted to scroll up to top of the article to check it was written a decade ago, I have a few facts for you to consider.

Bodybuilders have used these scientific principles for decades now to systematically increase and reduce body fat levels.

Go over the last century of metabolic research and you’ll find that every every single well-designed weight-loss study…including numerous meta-analyses and systematic reviews…has determined that we have to expend more energy than we ingest to achieve meaningful weight loss.

And every year a new  fad diets that deny the importance of energy balance pop up, and time after time they fail to gain acceptance in the weight-loss literature and eventually disappear.

The bottom line is this:

100 years of metabolic research has proven beyond question that energy balance, operating according to the first law of thermodynamics, is the primary mechanism that regulates body weight.

That doesn’t mean you have to count calories to lose weight, but you do have to understand the relationship between caloric intake and expenditure and weight gain and loss.

That also debunks the myth that eating certain foods directly helps us lose more weight than eating others.

The truth is as far as weight loss is concerned, foods don’t have special properties that make them “good” or “bad” to eat.

Read: The Best “Weight Loss Foods” (Thankfully) Aren’t What You Think

What foods do have, though, is varying amounts of calories and protein, carbs, and fat, and that means that some foods are better for losing or gaining weight than others.

Notice I said better, not bestmandatory, forbidden, or anything else that smacks of dogma because if you know how to regulate and balance your food intake properly, you can eat just about anything and lose weight.

Hard to believe, I know.

It helps explain phenomena like the curious case of Professor Mark Haub, though, who lost 27 pounds in 10 weeks on a diet of protein shakes and eating Doritos, Little Debbie snacks, Oreos and  Twinkies.

He wanted to prove one simple but very important point:

If you consistently consume fewer calories than you burn, you’ll lose weight, even if those calories come from junk food.

There’s a corollary here, too:

If you consistently consume more calories than you burn, you’ll gain weight, even if those calories come from the healthiest food on earth.

And all you have to do to find proof of this one is look around.

How many people do you know who are overweight despite their obsession with “clean eating“?

I can think of more than I can count, and now you know why.

Why You Must Get Your “Macros” Right


I think I’ve made my point that where weight is concerned, a calorie is a calorie.

No matter how healthy or clean food may be, if you eat too much of it, you’ll fail to lose weight.

And if you eat a nutritionally bankrupt diet of junk food but keep your caloric intake lower than your expenditure, you’ll lose weight.


If your goal is to build muscle and lose fat–optimize body composition–a calorie is not a calorie. A carefully controlled diet of junk food will no longer cut it.

In this case, the macronutrient profile of the individual foods you eat is of great importance.

The point here is our objective isn’t as simple as losing or gaining weight.

We may say those words but what we really mean is losing fat and not muscle and gaining muscle and not fat. And that makes some calories much more important than others.

For example, carbs and protein have more or less the same amount of calories per gram, but for building muscle and losing fat, protein is much more important.

Let’s talk about why… 

Protein Is King (or Queen, If You Prefer)

Your protein intake is going to determine your body composition far more than your carb or fat intake.

There are several reasons for this:

And if you’re working out regularly, eating enough protein is even more important because exercise further increases your body’s need for amino acids (which are what protein is made of).

Read: How Much Protein Do I Need? The Definitive (and Science-Based) Answer

You Should Probably Eat a Lot of Carbs

Google “How many carbs should I eat?” and you’ll find all kinds of answers from all kinds of trainers and “gurus.”

Many believe that low-carb is the way to go.

Others say it’s just a fad.

And then there are those who are somewhere in the middle.

This is where I stand:

If you’re healthy and physically active, and particularly if you lift weights regularly, chances are that you’ll do better with more carbs in your diet, not less.

And yes, that applies equally to gaining muscle and losing fat. The reality is a relatively high-carb diet can help you do both faster and easier.

Read: How to Know Exactly How Many Carbs You Should Eat

And You Probably Don’t Need As Much Fat As You Think (or Want to Eat…) 

Not so long ago, doctors, nutritionists, and self-styled experts convinced millions of people that eating fat made them fat.

They said nothing about caloric intake or energy balance or anything else you’ve just learned about.

Just cut and dried: eat fat and you get fat.

Savvy food marketers hopped on board and fat-free varieties of damn near everything starting filling the shelves, and as a result, many health-conscious people cut as much fat from their diets as possible.

While this is an effective way to control caloric intake (every gram of fat you eat contains about 9 calories), which is an effective weight management strategy, it overlooks a vital reality:

Dietary fat is an essential component of our diets.

It’s involved in many vital processes ranging from cell maintenance to hormone production, insulin sensitivity, and more, and if you eat too little, your health will decline.

 Read: How Many Grams of Fat Should You Eat Per Day?

Connecting the Dots 

We’ve covered a lot of ground so far, so before we get into figuring out your macros, let’s recap the key points.

1. Energy balance is the most important aspect of dieting.

How much energy you take in versus how much you use determines whether you gain or lose weight.

An energy surplus leads to weight gain, and an energy deficit results in weight loss.

2. How your calories break down into protein, carbs and fats is tremendously important.

High-protein is always the way to go and carb and fat intake can vary based on goals and circumstances. 

3. The least important aspect of your diet in terms of weight and body composition is the specific foods you’re eating

Nutrient-rich, “clean” foods supply your body with vital micronutrients that preserve and support your health, but they offer no inherent muscle building or fat burning advantages.

And from these points we can derive a simple, winning strategy:

Calculate your caloric intake, break it down into “macros,” and build a meal plan that has at least 80% of your calories coming from nutritious (“healthy”) foods.

This is the cornerstone of “flexible dieting” and it works tremendously well.

How to Calculate Your Calories and Macros

macronutrient calculator for cutting

 The macro calculator above has a number of important elements.

You input:

And it calculates:

  • Your basal metabolic rate (BMR)
  • Your total daily energy expenditure (TDEE)

And then, based on those numbers, you can set up your macros.

Let’s take a minute to discuss each of these functions.

BMR (Basal Metabolic Rate)

The amount of energy that you burn when your body is at rest is your basal metabolic rate.

Basal means “forming a base; fundamental” and the word metabolic refers to “the physical and chemical processes in an organism by which it produces, maintains, and destroys material substances, and by which it makes energy available.”

Your basal metabolic rate is basically the smallest amount of energy you need to stay alive.

You can use several mathematical equations to estimate your BMR with a fair amount of accuracy, and the calculator in this article uses the one most popular in fitness circles (the Katch-McArdle equation). 

TDEE  (Total Daily Energy Expenditure)

The total amount of energy that you burn in one day (24 hours) is your total daily energy expenditure.

Your basal metabolic rate (BMR) and the energy you burn through physical activities and the digestion and processing the food you eat summate to your TDEE.

Now, if this is starting to sound too much like math class, don’t worry.

You don’t have to break out the spreadsheets and try to figure out exactly how much energy you’re burning every day based on exactly what you’re doing and eating.

You also don’t have to record readouts on cardio machines (they’re inaccurate anyway)  or buy a FitBit to track every step you take.

As you see in the calculator, you can simply multiply your BMR based on your general activity level.

It won’t be completely accurate, of course, but it doesn’t have to be.

Instead, it will give you a good starting point for your caloric intake, and you can then increase or decrease your intake based on how your body actually responds.

Read:The Definitive Guide to Why You’re Not Losing Weight

How to Set Up Your Calories and Macros for Maximum Fat Loss

macronutirent ratio

If you want to lose fat (and not muscle) as quickly as possible, do the following:

Set your caloric intake to 75 to 80% of your TDEE (25 and 20% deficit, respectively).

Research shows that, when combined with regular resistance training, this will allow you to lose fat rapidly without having to sacrifice muscle.

Set your protein intake to 1 to 1.2 grams per pound of body weight.

This may sound excessively high to you, but it’s not. Studies show it can favorably influence body composition.

If you’re a man with 25% or more body fat or a woman with 30% or more, however, set your protein intake at 40% of your total calories instead.

If you have a healthy metabolism and you exercise regularly, set your fat intake to 0.2 to 0.25 grams per pound of body weight.

This will give your body what it needs for overall health and allow you to eat a large amount of carbs.

Get the rest of your calories from carbs.

Trust me–eating carbs doesn’t make you fat or make it harder to lose fat. Only overeating can do that.

On the contrary, keeping your carbs high means better workouts, more enjoyable meal plans, and higher energy levels and lighter moods.

The exception here is people who have a metabolic disease like type 2 diabetes or live a sedentary lifestyle. In these cases, they’ll do better with fewer carbs (generally around 25% of total calories or less).

How to Set Up Your Calories and Macros for Maximum Muscle Gain

Before we get into specific numbers here, you should know this:

You shouldn’t be “bulking” unless your body fat percentage is in the right range.

If you’re a guy, your body fat percentage should be about 10% before you bulk, and if you’re a woman, your body fat percentage should be right around 20%.

Read: The Ultimate Guide to Bulking Up (Without Just Getting Fat)

Now that we have that straight, here are my recommendations for your bulking diet:

  • Set your calories to 110% of TDEE.
  • Set your protein to 1 gram per pound of body weight.
  • Set your fat to 0.3 to 0.4 grams per pound of body weight.
  • Get the remainder of your calories from carbs.

How to Set Up Your Calories and Macros for Maintenance

I wouldn’t recommend this option until you’ve basically achieved the body you want. Until then, you should bulk and cut.

Here’s how to maintain your current physique:

  • Set your calories to 100% of TDEE.
  • Set your protein to 0.8 to 1 gram per pound of body weight.
  • Set your fat to 0.3 to 0.4 grams per pound of body weight.
  • Get the remainder of your calories from carbs.

Presets, Deficit and Surplus, and Macro Sliders

The calculator comes with presets to quickly get your calories and macros based on your goal.

  • If you want to lose fat, chose the “cut” preset.

It’ll then set your caloric intake to 80% of your TDEE (20% calorie deficit) and your macros to 40% of calories from protein, 40% from carbs, and 20% from fat (a very standard breakdown in the world of bodybuilding).

  • If you want to maintain your current weight, select “maintain.”

Your caloric intake will be 100% of TDEE and your macros will adjust to 1 gram of protein per pound of body weight, about 0.3 grams of fat per pound of lean mass, and the remaining calories allotted to carbs.

  • And if you want to gain muscle, select “bulk.”

It’ll jump your calories to 110% of TDEE and set up your macros in the same way as maintenance.

If you’d like to set your own calorie deficit or surplus, you can do that too.

The macro sliders allow you to easily change your macros as you see fit, and as you’ll see, once you input your protein intake, it stays locked. This makes it easy to increase or decrease fats and carbs by using the sliders or input fields without messing with your protein.

The Bottom Line on Macronutrient Calculators

macronutrient calculator bodybuilding

Many people find counting and tracking just calories burdensome enough.

The thought of keeping tabs on three different quantities sounds insufferable.

I assure you that it’s not. In fact, after a little while, it’ll just become second nature.

And more importantly, the payoff is enormous:

  • You can build muscle and lose fat with ease.
  • You can eat the foods you really like.
  • You can kiss cravings and hunger goodbye.
  • You no longer have to hope your diet will work (it will, every time, without fail).

So do yourself a favor even if you’re still skeptical.

Temporarily suspend your disbelief, put the strategies outlined in article into use for a few weeks, and you’ll be amazed by how well it works. You mirror can’t lie and neither can your scale.

What do you think about this macronutrient calculator? Have anything else to share? Let me know in the comments below!

+ Scientific References