Understanding macronutrients: What's the best macro ratio for weight loss?

Over the last few years, the macro diet — an eating approach where you focus on foods that fit into your daily macronutrient ratio — has gained a lot of popularity.

There are benefits to following this diet (which we'll get into later in the article) but getting started with it can be overwhelming. What is the right macro ratio? Are there specific dietary guidelines you should follow if you're trying to lose weight? What even are macros?

We're here to help. Here's everything you need to know about macronutrient ratios and how to calculate yours.

What are macronutrients?

Macronutrients, also referred to as macros, are nutrients that your body runs on and that it needs in large quantities in order to function properly.

There are 3 main macronutrients that you likely have heard about before: protein, carbs and fats. Your body doesn't make enough of these macros naturally, so it's important you consume them through your diet every day.

Let's dive into the role each macronutrient plays in your health and specifically, in your weight loss journey.

Protein

Protein is made up of amino acids, of which there are 20 types. Out of those, 11 can be made by your body, while the remaining 9 — known as essential amino acids — can only be gained through protein consumption.  

Protein is involved in many bodily processes. It helps:

• Support your immune system
• Promote muscle gain
• Support bone health by helping your body produce collagen
• Regulate a number of important hormones
• And more.

When it comes to weight loss, protein is actually the most satiating macronutrient. After you eat a high-protein meal, you feel fuller for longer — which means you're less likely to snack until your next meal and more likely to stay within your calorie deficit.

Protein also has a higher thermic effect than carbs or fats, meaning your body burns more calories digesting protein. As a result, it helps to boost your metabolism, so you burn more calories, even at rest.

And as we mentioned before, protein helps build muscle, which is an often underrated benefit for those trying to lose weight.

When you start dropping pounds, it's easy to lose muscle mass along with fat. However, the former is a lot more useful to your body than the latter, as it plays a key role in metabolic health, bone density, immunity, and more.

By eating enough protein (and doing resistance training), you can help your body preserve lean body mass as you simultaneously lose fat — achieving the healthy body composition you're after.

Top sources of protein

• Chicken
• Prawns
• Tuna
• Tofu
• Tempeh
• Eggs
• Edamame beans
• Greek yoghurt
• Cottage cheese
• Lentils and beans
• Protein pasta
• Protein powder

Carbohydrates

Carbohydrates, or carbs, are your body's main source of energy, which it uses for functions related to your muscles, brain, immunity and digestion, to name a few.

You may have heard people say that eating carbs leads to weight gain, so in order to slim down, you need to ditch them. But that isn't necessarily true.

Carbs can — and should — be part of a healthy, balanced diet, as long as a) you don't eat them in excess and b) you choose the right type.

Carbs can be simple or complex. Simple carbs, or simple sugars, are easy for your body to break down.

Though present in some healthy foods, such as dairy and fruits, simple sugars are most typically found in ultra-processed foods, like candy, cookies, soda and ice cream, which are high in calories but low in nutritional value.

Plus, simple sugars can cause a spike in blood sugar and insulin secretion, which may impact your health negatively and lead to increased hunger.

Complex carbohydrates, on the other hand, are harder for your body to digest — so the blood sugar increase that happens when you eat them is a lot more gradual.

Studies have shown that people who eat diets high in complex carbs and fibre tend to have lower rates of several chronic diseases when compared to those who prioritise simple carbs [1][2][3].

Top sources of complex carbs

• Quinoa
• Oats
• Sweet potato
• Lentils and beans
• Brown rice
• Buckwheat
• Butternut squash
• Beets
• Fruits like blueberries, oranges, apples and bananas

Fats

Fats also get a bad rep, but once again, unfairly. There are 4 types of fat:

• Trans fats
• Saturated fats
• Monounsaturated fats
• Polyunsaturated fats

The first two are unhealthy fats and they won't do much for your weight loss efforts. They raise your non-HDL cholesterol (the bad kind) and increase your risk of several cardiovascular conditions.

The second two, however, are actually good fats that help maintain healthy cholesterol levels, while also supporting nutrient absorption and immunity.

Not only that, but unsaturated fats can promote weight loss — as long as you're not consuming so much that you end up going over your daily calorie budget [4].

Top source of healthy fats

• Avocado
• Fatty fish like salmon, tuna and sardines
• Eggs
• Chia seeds
• Flaxseed
• Olive oilNuts and nut butters
• Dark chocolate

Macros for weight loss: What's the best ratio?

For fat loss, a common macronutrient ratio is:

• 45% of your daily calories from protein
• 25% of your daily calories from fats
• 30% of your daily calories from carbs

It's important to note, though, that these are general recommendations.

The right ratio for you will depend on several factors, like your age, activity levels, goals (for instance, whether you're focused on weight loss, fat loss or body recomposition), and genetics.

Something else to keep in mind is that the most important thing when it comes to losing weight is: you need to be in a calorie deficit. In other words, you need to be eating fewer calories than you burn.

Pros and cons of macro counting

So, if the number of calories you consume is more relevant for weight loss, do you really need to be tracking macros? Well, it is a personal choice, and there are pros and cons to doing so.

On one hand, counting macros helps you:

• Prevent nutrient deficiencies
• Understand what healthy portions look like
• Understand how specific foods (and food groups) make you feel
• Understand how to read food labels and in turn, choose healthy foods easily
• Figure out what works and doesn't work for your body, based on data

However, similar to counting calories, counting macros may not be the right choice for those who struggle, or have struggled, with an eating disorder, as it can turn into an obsessive habit, rather than a healthy one.

It also takes time and effort, so those who have a busy lifestyle to start with can find macro counting tricky to stay on top of.

How to calculate your macros

As we mentioned before, the ideal macro ratio for weight loss is individual to each person and their circumstances.

There are a few ways to calculate your macros:

Mifflin St Jeor equation

If you want to do things manually, the Mifflin St Jeor equation can help you figure out your basal metabolic rate (BMR), and from there you can calculate how many grams to eat of each macronutrient.

Here's how you can do this:

1. Calculate your BMR [5]: 10 x body weight (kg) + 6.25 x height (cm) - 5 x age (years) - 161

2. Choose your activity level:

• Sedentary (little to no exercise, desk job): 1.2
• Lightly active (light exercise 1-3 days/week): 1.375
• Moderately active (moderate exercise 3-5 days/week): 1.55
• Very active (hard exercise 6-7 days a week): 1.725
• Extra active (very hard exercise and a physical job): 1.9

3. Calculate your total daily energy expenditure (TDEE): BMR x activity level

4. Adjust your TDEE according to your goals. For weight loss, this means subtracting calories from your total — typically 10-20% for sustainable results.

5. Calculate your macros based on your chosen ratio. For instance, if you went for the commonly recommended 45% protein, 25% fats and 30% carbs:

• Protein: (0.45 x TDEE)/4
• Fats: (0.25 x TDEE)/9
• Carbs:  (0.3 x TDEE)/4

So, let's say you're 50 years old, 165 cm and weigh 90 kilos. Your BRM would be:

10 x 90 + 6.25 x 165 - 5 x 50 - 161 = 1520 calories

You do weight training twice a week, so you're lightly active. Your TDEE is:

1520 x 1.375 = 2090 calories

You decide to go on a 400-calorie deficit, so your daily calorie intake should be:

2090 - 500 = 1590 calories

Finally, you choose to eat 45% protein, 25% fats and 30% carbs, so your final macros are:

• Protein: (0.45 x 1590)/4 = 179 g
• Fats: (0.25 x 1590)/9 = 44 g
• Carbs: (0.3 x 1590)/4 = 119 g

Macro calculator

There are plenty of macro calculators available online, like this one.

All you need to do is input your age, gender, height, weight, activity levels and goal. You can also include your body fat percentage, for more accurate results.

The calculator then lets you know how many calories you should be eating per day, as well as how many grams of protein, carbs, fats, sugar and saturated fat.

You can also choose between a balanced ratio, low-fat, low-carb, or high-protein diet.

Plus, the specific calculator we linked above provides you with a list of nutrient-dense foods, along with the protein, carb and fat contents of each, so you can always turn to that list if you're unsure what to add to your plate in order to reach your goals.

With the help of a dietitian

If you can afford it, working with a dietitian or nutritionist is another excellent option. They'll be able to give you a more personalised ratio than any calculator, taking into account every detail about your health and weight loss goals.

They can also support you if a certain ratio isn't working for you, and help you adjust it for better results.

With Juniper's Weight Reset Programme, you get unlimited support from dietitians to guide you through the programme, one meal at a time.

Plus, our app has hundreds of high-protein recipes you can try, that are not just healthy and delicious, but easy to fit within your calorie deficit.

If eligible, you can also access breakthrough weight loss medication, which can help you achieve up to 20% weight loss after one year.

How to track your macros

Here are different ways to track your macros effectively:

Food diary

One traditional method is to keep a handwritten food diary, in which you jot down everything you eat and drink throughout the day, along with the portion sizes.

You then check nutritional labels or online databases to discover the macronutrient content of each item. This method can be time-consuming, but it does offer a high level of customisation and control.

Mobile app

If you're looking for something quicker, there are plenty of apps that offer a macro counting feature, such as MyFitnessPal and Cronometer.

These apps come with extensive food databases, barcode scanners, and even meal suggestions to simplify the logging process.

You can set your macro goals, and the app will help you stay on track by providing real-time feedback on your progress throughout the day.

Spreadsheet

If you prefer not to rely on a third-party platform, you can always create a customised spreadsheet on Google Sheets or Excel.

With your sheet, you can input your food data and create formulas to automatically calculate your daily intake — and it is a great middleground between a physical food diary and an app.

Image credit: Pexels / Ella Olsson