What Are Macros? A Beginner’s Guide to Macronutrients

You’ve probably heard the term macros thrown around. But what exactly are macronutrients, do you need to track them, and how can you get started? 

What are macros? 

The definition of macronutrients

Macronutrients, commonly referred to as “macros,” are the main nutrients your body requires to function optimally. They provide the energy needed for daily activities, exercise, and maintaining vital bodily processes. 

The three primary macronutrients are protein, carbohydrates, and fats. Unlike micronutrients like vitamins and minerals, which are needed in smaller amounts, macronutrients form the foundation of a healthy diet. Understanding the balance of these nutrients is key to achieving fitness goals and supporting overall health.

Micronutrients, on the other hand, are the vitamins and minerals your body needs (in much smaller amounts) to function. 

The importance of macronutrients

Understanding and managing your macronutrient intake is a key tool for achieving fitness goals, whether it’s weight loss, muscle building, improving body composition, or enhancing athletic performance. Unlike calorie counting alone, which only focuses on energy balance, tracking macros ensures that your body gets the right nutrients to function optimally. 

For weight loss, a well-balanced macro ratio helps preserve muscle mass while reducing body fat, preventing the metabolic slowdown that often accompanies crash diets. 

When building muscle, sufficient protein intake supports muscle repair and growth, while carbohydrates provide the energy needed for effective workouts. Those aiming for body recomposition—losing fat while gaining muscle—benefit from a strategic balance of protein, carbs, and fats to maintain strength while shedding excess weight. 

Meanwhile, athletes rely on the right macro balance to optimise performance, endurance, and recovery. By tailoring your macronutrient intake to your specific goal, you can improve results, enhance overall health, and sustain long-term progress.

Not sure what types of food to eat to achieve your goals? Check out our guide to what to eat to lose fat and build muscle. 

The three types of macronutrients

Protein: The building block of muscle

Protein plays a crucial role in muscle repair, recovery, and growth, and is essential for everyone—regardless of whether you’re hitting the gym or not. 

However, if you’re aiming to build muscle, protein is the cornerstone of this process. When you exercise, especially during strength training, your muscle fibres experience small tears that need to be repaired. Protein provides the amino acids necessary for this process, helping to repair existing muscle tissues and build new muscle over time.

In addition to supporting muscle recovery, protein plays a vital role in maintaining a healthy immune system, producing enzymes, and regulating hormones. High-quality protein sources include lean meats, fish, eggs, dairy products, and plant-based options like tempeh or tofu. 

How much protein should I eat?

The topic of how much protein to eat is hotly debated. If you’re new to tracking your macros and are lightly active, aim to eat 1.5-2.2g of protein per kg of body weight. If you’re more active, or aiming to actively gain muscle, you may want to aim higher—try 2.0-2.6g of protein per kg of body weight. Athletes, older adults, and those who are pregnant or breastfeeding are also likely to have higher protein requirements. 

Like all nutrition, protein requirements will vary depending on your activity level and goals. Seeking the personalised guidance of a nutrition coach can be a great way to maximise your results.

Carbohydrates: The body’s main energy source

Carbohydrates are the body’s preferred fuel, providing us with the energy we need for everything from high-intensity workouts to basic daily activities like walking and thinking. When consumed, carbohydrates are broken down into glucose to provide energy to cells throughout the body. Carbohydrates help sustain performance during exercise and speed up recovery by replenishing glycogen stores. 

Carbohydrates come in two main forms: simple carbs, found in sugary snacks and refined grains, and complex carbs, found in whole grains, legumes, and starchy vegetables. While simple carbs provide quick energy, complex carbs offer a steadier release, along with essential nutrients and fibre. Focusing on nutrient-dense sources like oats, brown rice, quinoa, and sweet potatoes can support energy levels and overall health.

Despite the popularity of low-carb diets, carbohydrates are a crucial nutritional component. Eating a very low-carb or keto diet can lead to fatigue, headaches, and more—and it’s also not essential for weight loss. 

Fats: Essential for hormone health and energy

While fats often get a bad reputation, this macronutrient is indispensable in maintaining overall health. Fats are crucial for hormone production, including those that regulate metabolism, growth, and reproductive health. Fats also serve as a concentrated energy source, particularly during low-intensity activities and when the body’s carbohydrate stores are depleted. Additionally, they help absorb fat-soluble vitamins like A, D, E, and K, which are essential for various bodily functions. 

Fats come in different types: saturated fats, monounsaturated fats, polyunsaturated fats, and trans fats. Ideally, most of your fat intake should come from unsaturated sources such as avocado, nuts, seeds, olive oil, and fatty fish like salmon. However, saturated fats play an important role in producing key sex hormones, and should be included in the diet in moderation. Trans fats, which are heavily processed or heated unsaturated fats, should be avoided at all costs. These fats increase LDL cholesterol and are linked to an increased risk of heart attack and stroke. 

Is alcohol a macronutrient?

In addition to protein, carbs, and fat, alcohol is often referred to as the fourth macronutrient. 

Why is alcohol a macro? Alcohol provides energy, delivering 7 kilocalories per gram—more than carbohydrates and protein (at 4 kcal/g) but less than fat (9 kcal/g). 

Unlike the other three macros, alcohol is not required for survival and does not contribute to bodily functions like tissue repair or enzyme production. Once consumed, alcohol is rapidly absorbed and metabolised primarily in the liver. However, because the body prioritises alcohol metabolism over other energy sources, excessive intake can disrupt fat oxidation and the successful absorption and use of other macros. This, in turn, can contribute to fat storage, higher blood sugars and a host of other issues.

As you track your macros, it’s important to not only track the caloric impact of any alcohol consumption but also to be conscious of whether it could be slowing your fitness journey.  

How to track and calculate macros for your goals

Tracking macros can be a game-changer for achieving your fitness goals, whether you want to lose weight, build muscle, or improve body composition. Here’s a step-by-step guide to help you get started:

Step 1: Identify your goal

Do you want to lose weight? Build muscle? Work towards a PB? The right macro breakdown for you will depend on what goal you want to achieve. 

• Weight loss: Create a calorie deficit while getting adequate protein to maintain muscle mass.
• Muscle gain: Create a calorie surplus that includes sufficient protein and carbohydrates.
• Body recomposition: Balance calorie intake around maintenance while ensuring enough protein for muscle retention and fat loss.

Step 2: Calculate your calorie needs

Once you know what you want to achieve, it’s time to calculate your calorie intake. 

Use a Total Daily Energy Expenditure (TDEE) calculator to estimate how many calories you burn daily. Then, calculate your calorie target based on what you want to achieve:  

• For fat loss: Reduce by 10-20% of TDEE (usually 250-500 kcal deficit).
• For muscle gain: Increase by 5-15% of TDEE.
• For recomposition: Stay close to maintenance while prioritising protein.

In a calorie deficit and not seeing the results you want? Check out our guide to why your calorie deficit might not be working. 

Step 3: Set your macro ratios 

Next, decide how much of your calorie budget will be dedicated to each macronutrient. This is often referred to as a macro ratio or macro split. 

As a general daily macro intake guide, try:

• Protein: 15-35% of total daily calories 
• Fats: 20-40% of total daily calories.
• Carbohydrates: 30-60% of total daily calories

This framework can be adapted depending on your goals and preferences. If you’re trying to lose fat or build muscle, aim towards the higher end for protein. 

And remember—you don’t need to cut out carbs or fat to lose weight. Low-carb and low-fat diets work equally well, but how you split your macros can affect other factors such as hunger, satiety, and adherence to your diet. Similarly, your physiology and bloodwork can help determine the best macro split for you. For those living with higher blood sugar, a strategic approach might include getting fewer calories from carbs and opting for low glycemic index (GI) choices. 

Step 4: Track your macros 

You can track your macros the same way you track your calories—by using a reliable food database such as MyFitnessPal, USDA FoodData Central, or Nutritionix. If you’re not already tracking your food intake, this can take a little getting used to. 

For best results, make sure to: 

• Avoid under- or overestimating portions
• Track your entire intake, including beverages, snacks, and bites of food
• Look up the exact brand of packaged foods
• Weigh, don’t estimate, for serving sizes

Planning ahead is one of the best ways to ensure your daily intake hits your macro goals. As you become familiar with the most appropriate foods for your goals, you may be able to eat more intuitively while still hitting your goals. 

What are the best macros for weight loss?

The best macro ratio for weight loss depends on your preferences and lifestyle, but a common approach is to prioritise high protein intake, moderate fat, and controlled carbohydrates. A typical macro split for fat loss might be 40% protein, 30% fats, and 30% carbohydrates. Protein is crucial for preserving muscle mass while in a calorie deficit, fats support hormone function, and carbohydrates provide energy for workouts and daily activities. Ultimately, the key to successful weight loss is maintaining a calorie deficit while consuming foods that help you stay full, fuelled, and satisfied.

Do I have to track macros?

You don’t have to track macros to meet your fitness goals. Losing weight comes down to a calorie deficit, and building muscle can be achieved with a calorie surplus and adequate protein (which only requires tracking one macro). 

However, tracking your macros will give you a consistency in your diet that you’re less likely to hit without. This can be especially helpful if you’re a high-level athlete or working towards a highly specific goal. 

If macro counting doesn’t work for you, that’s okay. For some people, it can be helpful to track macros for a short period of time, to get a sense of where they’re at and what ratio they’re hitting with their usual diet, and then give tracking a break. For others, in-depth tracking isn’t a reality based on their lifestyle, time, and energy. 

Wherever you’re at with your nutrition, My Vital Metrics is here to offer you a helping hand. Our online Bespoke Nutrition Coaching service meets you where you’re at and gives you the tools and data you need to reach your goals.