What are Macronutrients and Micronutrients? A Complete Guide

What are macronutrients and micronutrients? And … why should you care?

After all, for a long time, the number of calories you eat daily was all that matters. If you’re in a calorie deficit, you will lose weight. Slip into a calorie surplus, and you’d gain weight. 

But counting calories doesn’t give you the full picture. More specifically, it fails to tell you anything about how balanced or nutritionally-dense your diet should be.

For 1,800 calories a day, you could eat an entire Classic Hand Tossed Cheese Only pizza from Domino’s. Or 25 Snickers bars. Neither of which would be healthy (1, 2). 

Calorie-tracking is indeed a fantastic first step. But you’d also need to take into account the nutritional composition of your diet. 

And that means familiarizing yourself with two new terms: macronutrients and micronutrients. But wait, what are macronutrients and micronutrients? That’s what I’m going to cover in a bit!

What are macronutrients?

As implied by its name, macronutrients are nutrients that your body needs in large quantities. 

Protein, carbohydrates, and fat are the big three macronutrients. And they each have a caloric energy value (3, 4, 5, 6). 

Now, almost every food you eat contains a combination of the 3 macronutrients. Here’s how 1 gram of each macronutrient translates into calorie-count:

• Carbohydrates: 4 calories (7)
• Protein: 4 calories (8)
• Fat: 9 calories (9)

There are other energy-containing nutrients. Examples include alcohol (7 calories per gram), glycerine (4.32 calories per gram), and fiber (about 4 calories per gram). 

But hey, this is not a thesis on every energy-containing compound available. So, I’ll limit this article’s discussion to the three primary macronutrients we typically consume. 

Why are macronutrients important?

Macronutrients do not only provide you with energy! Each macronutrient also plays a vital function within your body.

Let’s take a closer look at what each of them does.

Protein

Protein is made up of amino acids that join together to form long chains. Note that they’re not just something you eat! Truth is, proteins actually mediate many vital processes in your body.

Many hormones, such as growth hormone, insulin, IGF-1, are proteins. Enzymes are proteins, too. 

Think of it this way. Proteins are found throughout your body. So, in muscle, bone, skin, hair, bone, and, well, virtually every other body tissue or part.

Bodily functions of protein

Some of the crucial bodily functions they carry out include:

• Promoting growth and maintenance of tissues (10, 11, 12, 13, 14, 15)
• Stimulating muscle protein synthesis (MPS) (16, 17, 18)
• Catalyzing bodily functions (19, 20)
• Transmitting information between cells, organs, and tissues (21, 22)
• Providing your body with structure, strength, and elasticity (23, 24)
• Maintaining healthy pH values of your bodily fluids (25, 26)
• Protecting your body from foreign invaders (27, 28)
• Transporting nutrients throughout your entire body (29, 30, 31)
• Serving as an energy source when your body is low on calories or carbohydrates and fats (32, 33)

Consuming sufficient dietary protein is essential. Unlike extra fat (which we can store easily around our bellies, hips, and thighs), our bodies don’t store lots of excess amino acids. 

So, your body is always using, recycling, and passing out excess protein. 

What happens if you don’t get enough protein in your diet? Well, you could run into a whole host of health problems in the long-term!

Issues like a loss of muscle mass weakened functioning of the heart, and even premature death may become a reality for you (34). Yikes!

Carbohydrates

To start, note that carbohydrates come in many forms (35):

• Monosaccharides: Single-sugar molecules, such as glucose, fructose, and galactose
• Disaccharides: Two sugar molecules linked together, such as sucrose (glucose linked with fructose)
• Oligosaccharides: A broad category that encompasses short-chain saccharides and includes disaccharides
• Polysaccharides: Complex carbohydrates, such as starch, which has large numbers of saccharides bonded together

Keto diet enthusiasts are right. Carbohydrates aren’t (technically) essential macronutrients. 

Does your body need carbohydrates?

Your body doesn’t need carbohydrates to survive. But (yes, there’s always a but) that doesn’t mean that they have zero benefits. Far from it, really.

During digestion, carbohydrates (excluding fiber) are broken down into monosaccharides. And these compounds then enter your blood circulation. 

In this way, all carbohydrates (except fiber) wind up as sugar in your body after digestion (36).

Glucose, in particular, is of crucial importance to survival. 

Red blood cells require glucose as they cannot use fat or ketones (by-products of fat breakdown) for energy. 

And under normal conditions, your brain will also almost exclusively use glucose for energy. Except in times of prolonged fasting, starvation, and ketogenic diets. 

Whether you’re looking at your favorite HIIT sessions or your regular gym workouts, glucose is required for anaerobic activity. So – yes, you’re relying on glucose any time you’re sprinting. Or lifting to failure in the gym.

You may be wondering … if glucose is so crucial, how come those on keto diets are still around to judge you for eating bread?

Well, that’s because our livers are perfectly capable of making all the glucose we need for survival in a day. Our livers do so through gluconeogenesis (GNG), even if we don’t eat any carbohydrates (37). 

Do note the keyword, ‘survival,’ though. Merely surviving is an entirely different ballgame from thriving.

If you’re interested on what the keto diet tries to achieve by cutting out carbohydrates, check out this article on how the keto diet works and if it’s worth trying.

Fat

Fats, also known as lipids, come in a diverse array of forms. Such as oils, fatty acids, waxes, and steroids. 

Unlike carbohydrates, fats are essential nutrients. That’s because your body cannot make certain fats called essential fatty acids (EFA) (38, 39, 40).

Unfortunately, fats have been wrongfully demonized for a long time. Just think of the wide range of low-fat diets and products available in the market!

Many people believe that they’ll get fat simply because they’re eating fat. But that’s not true.

Research consistently shows us that we’ll only put on weight when we continuously eat in a calorie surplus (41, 42, 43, 44).

So, there’s really no reason to squeeze the oil out of your truffle fries. Or skim the oil floating on the surface of your soup. As long as you’re keeping an eye on your calorie intake, consuming fats is perfectly fine. 

Bodily functions of fat

More importantly, fats perform a variety of essential processes in the body, including:

• Forming part of the lipid bilayer of cells
• Regulating membrane permeability
• Serving as a source of fat-soluble vitamins
• Acting as a storage reservoir for energy

Sufficient fat consumption is also crucial for your hormonal balance. 

Lowering your fat intake until it accounts for less than 20% of your daily calorie consumption might cause your testosterone levels to drop. (Yes, females have and need testosterone too!) 

That’s not beneficial for keeping lean body mass and strength. Both of these are important for long-term weight loss maintenance and prevention of weight regain (45).

That said, you shouldn’t start dousing your meals in olive oil. 

As long as you’re allocating at least 20% of your daily calories to dietary fat, your testosterone levels won’t decrease. 

What’s more, it can be challenging to create a calorie deficit if your fat intake is too high. Remember? Fats give 9 calories per gram. That’s over double the calories of protein or carbohydrates!

Okay, that’s enough. So, what’s the optimal intake, then? That brings us to the next section. 

What is the optimal macronutrient ratio?

According to the Institute of Medicine of the National Academies (AMDR), the acceptable macronutrient distribution for most is as follows (46):

• Carbohydrates: 45-65% of calories
• Fats: 20-35% of calories
• Protein: 10-35% of calories

I know, that’s a huge range to work with. And for many, a protein intake of 10% to 35% of your calorie intake may not be sufficient. 

The figures above represent the minimum intake needed to prevent malnutrition. But we’re not talking about nutritional deficiencies now, are we?

So, let us take a different approach when it comes to calculating your macronutrient ratio.

Of all the three macronutrients, protein is the most important. Because it helps improve (47):

• Retention of lean body mass (which helps you burn more calories)
• Satiety
• Fat loss

So, for these reasons, you should decide on your protein intake first. 

Step 1: Determine your protein intake

Your individual protein needs depend on your health, body composition, fitness goals, and level of physical activity. But you already knew that, right?

What you’re interested in finding out are specific numbers. 

I have also explored the optimal protein intake for your fitness goals but here’s the gist of it if you’re short on time (48):

• Overweight or obese: 1.2-1.5 grams per kilogram of body weight
• A healthy weight, active, and trying to lose weight: 1.8-2.7 grams per kilogram of body weight
• A healthy weight, active, and trying to gain muscle: 1.4-2.4 grams per kilogram of body weight
• Experienced lifter on a bulk: 3.3 grams per kilogram of body weight

Admittedly, the range can be intimidating. 

How would you know whether to go with 1.8 grams or 2.7 grams of protein per kilogram of bodyweight if you’re trying to lose weight?

For example, let’s assume that you:

• Are active
• Weigh 55 kilograms
• Have an optimal daily calorie intake of 1,800 calories

You would need to eat 121 grams of protein per day (Math: 2.2 x 55 = 121). Since each gram of protein gives you 4 calories, you’d be allocating 484 calories out of your daily total calorie ‘budget’ to protein. 

You, therefore, have 1,316 calories left to distribute between your carbohydrates and fats.

Step 2: Settle on your preferred carbohydrates-fat ratio

So, what should you do with your distribution of carbohydrates and fat calories?

This might shock some people, but it’s really up to you. Just be careful that you’re not going below 20% of your calorie intake for fats. 

Contrary to what anti-carb or anti-fat dieters would have you believe, it turns out that all reduced-calorie diets are equally successful in promoting similar weight loss. Yes, regardless of the macronutrient ratio (49, 50, 51, 52)!

Any reduced-calorie diet cause similar amounts of weight loss in the long term. 

Research clearly demonstrates that fat loss and muscle retention are similar when calories and protein are equated.

Ultimately, it’s eating in a calorie deficit that matters most.

Once again, you may be looking at this section with a ‘WTF’ face because this doesn’t give you any actionable insights. 

Okay, let me help you out. 

While every individual is different, a good starting point is 55-60% carbohydrates to 40-45% fat. Note that this is after subtracting protein calories from total energy intake.

Remember how you had 1,316 calories left? If you’re going with 60% carbohydrates and 40% fat, your intake will be the following:

• Carbohydrates intake:
  • 0.6 x 1,316 = 789.6 calories
  • 789.6 / 4 = 197.4 grams of carbohydrates
  • Note: 1 gram of carbohydrates gives 4 calories

• Fat intake:
  • 0.4 x 1,316 = 526.4 calories
  • 526.4 / 9 = 58.5 grams of fat
  • Note: 1 gram of fat gives 9 calories

Step 3: Adjust as needed

While macronutrient ratio doesn’t matter in ultimate weight loss results, it can affect how you feel about adhering to a diet with fewer calories.

As you probably already know, sustainability and long-term adherence is the greatest indicator of a successful diet.

Some people function well on a high-carb diet. Others? They work better on a high-fat diet. 

So, play around with the ratio of your carbohydrates to fat. And see how your body responds. 

For the most part, though, avoid going too low with your carbohydrates or fats. 

As mentioned earlier, decreasing your fat intake too much can wreak havoc on your hormone levels. 

And there are a few notable downsides to dropping your carbohydrates intake (ketogenic, basically):

• Adherence: Most people cannot completely omit carbohydrates from their diet for long periods and adhere to it.

• Performance: Ketones, the energy source your body uses when you’re low on carbohydrates, cannot be used for anaerobic energy production. You won’t do as well if you’re doing intense weight training or repeated sprint-type exercises (53).

• Fat regains: Unless you plan on following a ketogenic diet till you die, you’re more likely to regain body fat post-diet as you’ve started eating carbohydrates again.

Ultimately, when deciding on your carbohydrates and fat distribution, you should pick something you enjoy and perform well on. Perhaps more importantly, pick something you can adhere to for the long-term.

What are micronutrients?

In fear of this article sounding like it’s hardcore advocating for the ‘If It Fits Your Macros’ (IIFYM) way of eating, here’s a crucial point to note. 

If you’re only counting calories and macronutrients, you may be missing out on essential vitamins and minerals (micronutrients). Even if you’re hitting your target macronutrient intake. 

But we’re getting ahead of ourselves. 

Macronutrients vs. micronutrients: What’s the difference?

By now, you must know what macronutrients are; and it’s now time to move on to micronutrients. As implied by its name, your body needs smaller amounts of micronutrients relative to macronutrients. You know, because of the ‘micro’ prefix. 

When we mention micronutrients, what we’re referring to are vitamins and minerals in general. Unlike macronutrients, micronutrients are not energy-releasing compounds (54). 

Why are micronutrients essential?

As with macronutrients, micronutrients can also be divided into separate categories:

1. Water-soluble vitamins
2. Fat-soluble vitamins
3. Macro-minerals
4. Trace minerals

Regardless of type, micronutrients are vital for immune function, brain development, growth, and many essential functions. 

Let’s take a closer look at each category and what they do for your body.

Water-soluble vitamins

Water-soluble vitamins dissolve in water. They are not easily stored in your body, and get flushed out with your urine when consumed in excess.

Here’s the list of water-soluble vitamins, with some of their functions:

• B1 (thiamine): Converts nutrients into energy (55).
• B2 (riboflavin): Crucial for cell function, fat metabolism, and energy production (56).
• B3 (niacin): Responsible for producing energy from food (57).
• B5 (pantothenic acid): Necessary for fatty acid synthesis (58).
• B6 (pyridoxine): Helps with the release of sugar from stored carbohydrates for energy (59).
• B7 (biotin): Essential for proper cell division (60).
• B9 (folate): Necessary for proper nervous system, brain function, and red blood cell formation (61).
• B12: Essential for red blood cell formation, neurological function, and DNA synthesis (62).
• C (ascorbic acid): Required for the creation of neurotransmitters and collagen (63).

Fat-soluble vitamins

As can be inferred from its name, fat-soluble vitamins do not dissolve in water. Instead, they’re best absorbed when consumed with a source of fat.

Here’s the list of fat-soluble vitamins, along with some of their functions:

• A: Vitamin A is essential for proper organ function and vision (64).
• D: Vitamin D assists in calcium absorption and, therefore, bone growth (65).
• E: Vitamin E acts as an antioxidant that protects cells from free radical damage (66).
• K: Vitamin K is required for proper bone development and blood clotting (67).

Macro-minerals

Macro-minerals are needed in more massive amounts (in comparison to trace minerals, which we’ll cover in a bit) to perform their functions in your body.

Here’s the list of macro-minerals, with some of their functions:

• Calcium: Necessary for proper structure and function of teeth and bones. Assists in blood vessel contraction and muscle function (68).
• Phosphorus: Part of bone and cell membrane structure (69).
• Magnesium: Helps with over 300 enzymatic reactions, including regulation of blood pressure (70).
• Sodium: Electrolyte that helps with the balance and maintenance of blood pressure (71).
• Chloride: Often found in combination with sodium. Helps maintain fluid balance and is used to make digestive juices (72).
• Potassium: Electrolyte that maintains fluid balance in cells and helps with muscle function and nerve transmission (73).
• Sulphur: Part of every living tissue and is contained in the amino acids cysteine and methionine (74).

Trace minerals

Trace minerals are needed in smaller amounts. But they are, nonetheless, crucial in enabling critical bodily functions.

As usual, here’s the list of trace minerals and some of their functions:

• Iron: Helps transport oxygen to muscles and assists in the creation of certain hormones (75).
• Manganese: Assists in carbohydrates, amino acid, and cholesterol metabolism (76).
• Copper: Essential for connective tissue formation, plus normal brain and nervous system function (77).
• Zinc: Necessary for healthy growth, immune function, and wound healing (78).
• Iodine: Assists in thyroid regulation (79).
• Fluoride: Crucial for the development of teeth and bones (80).
• Selenium: Important for thyroid health, reproduction, and defense against oxidative damage (81).

How do I know if I’m getting enough micronutrients?

Hopefully, you now see that getting enough micronutrients into your diet is crucial for health. 

It doesn’t matter what your preferred eating pattern is. Even if you’re trying out the popular intermittent fasting approach, you shouldn’t neglect to get a good variety of micronutrients through your foods.

And the best way to ensure that you’re fulfilling your nutrient needs is to eat a well-rounded diet, with plenty of fruits, vegetables, legumes, whole grains, and lean sources of protein, along with healthy fats, such as nuts and olive oil (82).

So, whenever possible, you should meet your vitamin and mineral needs through your diet. You know, instead of relying on supplements.

That said, it could be challenging for some of us to meet these nutrition goals, especially when you eat out very often.

A good place to start is by meal prepping just once or twice a week. This gives you the time to get used to eating a variety of nutritious foods without having the stress of cooking and preparing meals daily. And with time, you’d hopefully be able to prepare your own meals more often and depend less on takeouts.

Knowing what macronutrients and micronutrients are helps you eat better

Yes, the amount of calories you eat is crucial. It’s ultimately what decides whether you’re shedding weight, or piling it on, after all. 

But in addition to caring about your calorie count, you should also pay attention to the quality of those calories. How are you spreading your macronutrients through your foods? 

And perhaps more importantly, choose to opt for nutrient-dense foods most of the time. Just because eating 10 doughnuts every day technically ‘fits your macros’ doesn’t mean it’s a wise choice.

That said, now that you know what macronutrients and micronutrients are, you’re more well-equipped to make better food decisions. I trust you!