Counting macronutrients is supposedly the new counting calories, but can it really make you fitter and healthier as advocates claim? We asked a dietitian for the lowdown on maths-heavy meal-planning…

Any products in this article have been selected editorially however if you buy something we mention, we may earn commission

Whether on the gym floor, on social media or through the health and fitness grapevine, there’s been much talk of late of ‘counting your macros’. Originally a method used by bodybuilders to achieve specific results, working out the ratio of carbohydrate, protein and fat in your daily diet is gaining ground as a more efficient and thorough way to reach your goals than counting calories or other ‘deprivation’ based methods, but is it really a failsafe way to stay on the health wagon? We quizzed registered dietitian and author of  The Low-Fad Diet Jo Travers Bsc RD  on the who, where, whats and whys of counting macronutrients. Scales and calculators at the ready…

First things first, what is a macronutrient?

Essentially it's a nutrient that we that we need large amounts of in the diet, namely protein, carbs and fat. Macros are all sources of energy (calories). Don't forget that alcohol fits into the macronutrient description, but we don't actually 'need' it.

We've heard a lot on the topic of 'counting your macros'. What does this entail?

It basically means figuring out a target number for each of the macronutrients and then eating foods that add up to those numbers. The way the theory goes is that it doesn’t matter which foods you eat, as long as you meet your macro numbers. So if you want to eat nothing but pizza and your macros “fit” then with this diet, that’s all good.

In reality though it isn’t really that simple. You still need to think about all the micronutrients too (vitamins and minerals needed in smaller amounts) and it’s difficult to get all of them if you eat nothing but junk food.

How do you know what macronutrients you need in your individual diet?

It depends a bit on what you are trying to achieve. If you are a bodybuilder you will add more protein, if you are trying to lose weight then you will need less.

Calculating what you need can be done in two ways. For a more specific number, which is best for people who are very active, you can use a calculation using your basal metabolic rate (how much energy you use if you do absolutely nothing) and your activity level (how much you move). If you are less active, an easier way, which is not far off the other calculation, is to use your weight. Most people need about 1g of protein, 1-1.5 g carbohydrate and 0.8 g fat per kilo of body weight. So if you want to lose weight and you weigh 70 kg your calculation would look something like this:

Protein: 70 kg x 1 g protein = 70 g protein per day
Carbs: 70 kg x 1-1.5 g carbs = 70-105 g carbs per day
Fat: 70 kg x 0.8 g fat = 56 g fat per day

It sounds complicated- do I need any equipment? Is professional guidance recommended?

There are plenty of macro calculators online that you can use, but really the most complicated bit is getting what you eat to match your targets! Although hitting them exactly isn’t necessary, a few grams either way is not going to make much difference. Counting and recording everything can be quite tedious as well, but there are apps to help with this too.

If you are having any problems with weight management, such as hunger, tiredness, or you aren’t losing weight etc., I do recommend seeking professional guidance with diets of any kind. A bit of support can be the difference between getting where you want to be and giving up.

Why do you think that it's gained popularity of late?

The idea that you can eat whatever foods you like is pretty alluring and a diet can feel manageable if you have definite rules to follow and targets to meet.

What are the potential benefits of 'counting macros’?

Getting the balance of nutrients right is really important and I think it’s one of the reasons that calorie counting doesn’t work for a lot of people. Calories tell you just one thing about a food, and not necessarily the most important thing. If you choose a 600 kcal almond croissant (carbs and fat) instead of a 600 kcal Spanish omelette (protein, carbs, fat and veg), then it’s easy to see why the croissant may leave you hungry while the omelette ticks all the boxes and therefore keeps you going for longer.

What are the drawbacks?

We eat food, not nutrients and so making what you eat fit your macros can be tricky. The counting element is boring and lots of people get fed up with it. Also, because pre-packaged food has the macros written on the nutrition labels, it can steer people more towards processed food rather than cooking themselves which isn’t necessarily as healthy. Because micronutrients aren’t really taken into account, less focus is on them. This is an issue because pretty much every process that takes place in the body, from making a skin cell to immune system reactions, requires at least one vitamin or mineral to act as a catalyst or cofactor for that reaction to happen, so if you don’t get enough of them, the body often doesn’t function at its optimum level.

We've heard tell that counting macros is a superior method to simply counting calories in terms of weight maintenance and loss. What do you think?

I think that it’s much better to get a balance of nutrients so from that perspective it is better than calorie counting alone.

Finally, do you think that counting macros is a fad, or is it evidence based?

There is evidence behind counting macros and it can be useful for athletes for instance, but for most people I think it’s unnecessary and can get tedious very quickly. You can get what you need without counting everything by using your hands as measures. You need 4-6 fist-size portions of carbs, 2 palm-size portions of protein and 5 handfuls of fruit and vegetables every day. Your hands are great because you always have them with you, and if you are a giant you have giant hands and need giant portions, and if you are small you have small hands. Also, no matter what your weight status, your hands don’t really change much, so all this means they are a really good guide to what you need without any calculations.

In combination with your hand-size measures, at mealtimes think of your plate split into three: fill half with veg or a mixture of fruit and veg, a quarter with protein and a quarter with carbs.

Curious about the 5:2 diet? For information, recipes, advice and first person accounts,  visit our 5:2 hub

Follow Jo on Twitter  @LDNnutritionist  and Anna  @AnnaMaryHunter