Macro Tracking Explained: The Complete Beginner's Guide

Macro tracking means recording how much protein, carbohydrate and fat you eat each day and aiming at a target for each one, rather than watching a single energy number. For most people the targets that matter are protein at roughly 1.6 to 2.2 grams per kilogram of bodyweight, fat at no less than 20 per cent of your energy intake, and carbohydrate taking up whatever energy is left.

Most people arrive here wanting the numbers first, so that is where we start. The working, and the honest limits of any calculator, come after.

Your macro targets by goal

These are daily targets in grams per kilogram of your current bodyweight. Multiply the number by your weight in kilograms. An 80 kg person aiming at 1.8 g/kg of protein needs 144 g a day.

Sources and derivation: protein figures follow Morton et al., British Journal of Sports Medicine, 2018, and Helms et al., International Journal of Sport Nutrition and Exercise Metabolism, 2014, described in full below. Fat figures are the per kilogram equivalent of 20 to 35 per cent of total energy, the acceptable range published by the National Health and Medical Research Council, with the 20 per cent floor from Thomas, Erdman and Burke, Medicine and Science in Sports and Exercise, 2016. Carbohydrate is not a target in its own right, it is the energy left after protein and fat are set, so those figures are calculated rather than prescribed. The size of the deficit and surplus is common practice among dietitians rather than a figure taken from one trial, and reasonable people set them differently.

A worked example, start to finish

Priya is 34, 168 cm tall and weighs 72 kg. She works at a desk and trains four times a week: three resistance sessions and one run. She wants to lose fat while holding onto muscle. Here is every step, so you can repeat it with your own numbers.

Sources: Mifflin et al., American Journal of Clinical Nutrition, 1990, for the equation. FAO/WHO/UNU, 2004, for the activity multiplier. Energy factors of 17 kJ per gram of protein, 37 kJ per gram of fat and 17 kJ per gram of carbohydrate are the values Food Standards Australia New Zealand uses to calculate the energy figure on a nutrition information panel.

Priya's daily targets: 144 g protein, 65 g fat, 196 g carbohydrate, 8,190 kJ. That is 30 per cent of her energy from protein, 29 per cent from fat and 41 per cent from carbohydrate, which sits comfortably inside every published range.

What macros actually are

Macronutrients are the three components of food that supply energy: protein, carbohydrate and fat. Alcohol is a fourth, at 29 kJ per gram, which is why it complicates a tracking week more than its volume suggests.

Total energy determines whether your weight goes up or down. The split between the three macros determines, to a large extent, what that weight is made of and how you feel while training. Two people eating the same kilojoules with very different protein intakes will not end up with the same body composition.

That is the entire argument for tracking macros rather than only kilojoules. It is a modest argument, not a dramatic one.

How much protein you actually need

Protein is the macro with the strongest evidence behind a specific number, and it is the one most people get wrong.

The best available synthesis is Morton and colleagues, published in the British Journal of Sports Medicine in 2018. They pooled 49 randomised controlled trials covering 1,863 participants. Protein supplementation alongside resistance training increased fat free mass by 0.30 kg on average (95% confidence interval 0.09 to 0.52 kg, p=0.007). The useful part is the breakpoint: gains stopped improving once total protein intake reached 1.62 g/kg/day, with a confidence interval running from 1.03 to 2.20 g/kg.

Note what that means. The average benefit of supplementation was small, roughly 300 grams of lean mass. And the confidence interval around the breakpoint is wide, which is why sitting near the top of it, around 2.0 to 2.2 g/kg, is a reasonable hedge rather than an established requirement.

Protein matters more, not less, when you are eating below your requirement. Helms and colleagues, in the International Journal of Sport Nutrition and Exercise Metabolism in 2014, reviewed six studies covering 13 groups of resistance trained athletes with relatively low body fat who were restricting energy. Body fat percentage fell in all 13 groups, but fat free mass also fell in nine of them. Their conclusion was that protein needs during energy restriction are likely 2.3 to 3.1 g/kg of fat free mass, scaled up as the deficit deepens and as the person gets leaner.

Six studies is a small base, and the review is about lean trained athletes rather than the general population, so treat the top of that range as an upper bound rather than a target. For someone at around 20 per cent body fat, 2.3 to 3.1 g/kg of fat free mass converts to roughly 1.8 to 2.5 g/kg of total bodyweight, which is where the fat loss row in the table above comes from.

The joint position statement from the American College of Sports Medicine, the Academy of Nutrition and Dietetics and Dietitians of Canada, published in Medicine and Science in Sports and Exercise in 2016, lands in the same place: 1.2 to 2.0 g/kg/day for athletes generally, and intakes as high as 2.0 g/kg/day or above when energy is restricted or training is interrupted by injury.

Fat has a floor, and it is worth respecting

Fat is the macro people cut first when they want the carbohydrate number to look better, and it is the one with a genuine lower limit.

The Australian and New Zealand nutrient reference values put the acceptable range for fat at 20 to 35 per cent of total energy. The 2016 sports nutrition position statement is more direct about the bottom of that range. It states that athletes should be discouraged from chronically eating below 20 per cent of energy from fat, because the loss of dietary variety that usually comes with it tends to reduce intake of fat soluble vitamins and essential fatty acids, particularly omega-3s.

You will see claims that very low fat intakes suppress testosterone and other hormones. The direction of that effect is plausible and there is some supporting work, but the studies are small and the size of the effect is contested, so we are not putting a number on it here. The nutrient argument above is sufficient reason to keep fat at or above one fifth of your energy.

In practice, 0.8 to 1.0 g/kg of bodyweight keeps most people safely above the floor without crowding out carbohydrate.

Carbohydrate is the flexible one

Once protein and fat are set, carbohydrate takes the rest. That is not laziness in the method, it is genuinely how the calculation works.

Carbohydrate is the fuel that most affects how a hard session feels. If your training quality is dropping, your sleep is fine and your protein is on target, carbohydrate is usually the first thing to raise. If you are eating in a deficit and feel flat in week three, that is expected, not a sign you have done the sums wrong.

Estimating your energy requirement

The Mifflin-St Jeor equation is the standard starting point. It was derived by Mifflin and colleagues from 498 healthy adults, 247 women and 251 men, aged 19 to 78, with resting energy expenditure measured by indirect calorimetry. It was published in the American Journal of Clinical Nutrition in 1990.

For men: resting energy expenditure = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5.

For women: resting energy expenditure = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161.

That gives kilocalories per day at rest. Multiply by 4.184 for kilojoules. Then multiply by an activity factor to get your total daily requirement. The FAO/WHO/UNU expert consultation on human energy requirements groups lifestyles into three physical activity levels: 1.40 to 1.69 for a sedentary or light activity lifestyle, 1.70 to 1.99 for an active or moderately active lifestyle, and 2.00 to 2.40 for a vigorously active lifestyle.

Two honest caveats. The equation predicts a group average, and individuals scatter around it, so your true resting expenditure may sit meaningfully above or below the number it gives you. And choosing between 1.7 and 1.9 changes your daily target by well over 1,000 kJ, which is more than most of the precision you are chasing elsewhere.

Treat the output as a starting hypothesis. Two to three weeks of consistent tracking and weekly weight averages will tell you more about your actual requirement than any equation can.

Does tracking itself help

It appears to, though the evidence is softer than the fitness industry implies.

Burke, Wang and Sevick reviewed the literature on self-monitoring in the Journal of the American Dietetic Association in 2011. They identified 22 studies published between 1993 and 2009, 15 of which looked at dietary self-monitoring. Their finding was that a significant association between self-monitoring and weight loss was consistently found, but that the level of evidence was weak because of methodological limitations. That is their wording, and it is worth keeping.

The largest single dataset comes from the Weight Loss Maintenance trial, reported by Hollis and colleagues in the American Journal of Preventive Medicine in 2008. Across 1,685 adults in the six month intensive phase, mean weight change was 5.8 kg (standard deviation 4.4 kg). Participants kept an average of 3.7 daily food records a week. After adjusting for race, gender and initial weight, greater weight loss was associated with more frequent attendance at group sessions, the number of food records kept per week, and minutes of moderate intensity physical activity per week.

That association is real and it is large. It is also observational within a trial, so it does not prove that record keeping caused the weight loss. People who log consistently may simply be people who are engaged with the plan in every other way too.

The accuracy problem nobody mentions

Here is the part most macro calculators leave out. Self-reported food intake is systematically too low, and the gap is not small.

Hill and Davies reviewed the validity of self-reported energy intake against the doubly labelled water technique, the gold standard measure of energy expenditure, in the British Journal of Nutrition in 2001. Across the studies they examined, under-reporting in adults typically ran between 11 and 30 per cent. In people with obesity it ranged from 19 to 59 per cent, and in athletes from 11 to 43 per cent.

The sharpest illustration is Lichtman and colleagues in the New England Journal of Medicine in 1992. They studied 10 people, nine women and one man, drawn from 224 consecutive patients, who reported eating under 1,200 kcal a day and were not losing weight. Their measured energy expenditure was within 5 per cent of predicted values, so metabolism was not the explanation. They under-reported their actual food intake by an average of 47 per cent, plus or minus 16 per cent, and overstated their physical activity by 51 per cent.

Ten people is a very small sample and they were selected specifically because they reported diet resistance, so do not read 47 per cent as typical. Read the direction as typical, and the magnitude as a warning.

This does not make tracking pointless. It makes the absolute number less trustworthy than the trend. If you log the same way every week, your logged intake going from 8,200 kJ to 7,400 kJ is meaningful information even if both figures understate reality.

What a week of tracking actually looks like

Using Priya's targets of 144 g protein, 65 g fat, 196 g carbohydrate and 8,190 kJ:

• Weigh food on training days for the first two weeks, then estimate on weekends. Eyeballing portions is where most of the under-reporting enters.

• Anchor protein first. Roughly 35 to 40 g at each of three meals gets her to about 110 g, and a fourth serve closes the gap.

• Expect two or three days a week to miss. Hitting protein five days out of seven and landing within about 400 kJ of target is a good week, not a failed one.

• Weigh yourself daily and use the seven day average. Day to day swings of 1 to 2 kg are water and gut contents.

• Review after three weeks, not three days. If the weekly average has not moved at all, reduce by about 400 kJ or add a session, and hold that for another three weeks.

Most people do not fail at macro tracking because the arithmetic was wrong. They fail because they set an aggressive deficit, tracked perfectly for nine days, and stopped.

Where your own data fits

Every number on this page is a population estimate applied to one person. Your actual energy requirement, your training load, your sleep and your weight trend are the data that correct it. That is the gap hlth.coach is built to close: it reads your wearable, training and body composition data and adjusts your targets as the evidence from your own week comes in, rather than leaving you with a figure calculated once in January.

The short version

• Protein: 1.6 to 2.2 g/kg of bodyweight daily, toward the upper end when you are in a deficit. The pooled evidence puts the point of diminishing returns at 1.62 g/kg, with a wide confidence interval.

• Fat: at least 20 per cent of your energy, and 20 to 35 per cent is the published acceptable range. Roughly 0.8 to 1.0 g/kg works for most people.

• Carbohydrate: whatever energy remains. Raise it if training quality is falling.

• Energy: Mifflin-St Jeor for resting expenditure, multiplied by 1.4 to 2.0 depending on how active you are. Treat the result as a starting hypothesis.

• Tracking is consistently associated with weight loss, but the evidence quality is weak and the association may not be causal.

• Self-reported intake is under-reported by roughly 11 to 30 per cent in adults. Trust your trend, not your total.

• Australian labels are in kilojoules. Divide by 4.184 for calories, or multiply calories by 4.184 for kilojoules.

Common questions

How do I calculate my macros?

Set protein first from your bodyweight, set fat to a sensible minimum, then let carbohydrate take the remaining energy. The tables above give the per kilogram targets by goal and a worked example that takes one person from estimated energy requirement to grams per day.

What is the best macro split for fat loss?

There is no single split that beats the others once protein and total energy are matched. Keep protein high to protect lean mass in a deficit, keep fat above its floor, and treat the carbohydrate share as a preference rather than a lever.

Do I need to hit my macros exactly?

No. Food labels carry tolerances, portion estimates drift, and your own energy expenditure varies day to day. Being close on protein and roughly right on total energy across a week matters far more than precision on any single day.

How accurate is food tracking?

Less accurate than most people assume. Self-reported intake is routinely under-reported when measured against doubly labelled water, and the gap can be substantial. That is not a reason to stop tracking. It is a reason to trust the trend on the scale over the arithmetic in the app.

Should I count kilojoules or calories?

Australian labels use kilojoules, most apps default to calories, and they measure the same thing. One calorie is about 4.18 kilojoules. Pick one and stay consistent so you are not converting in your head.

Does macro tracking actually work?

Self-monitoring of intake is one of the better supported behaviours in the weight management literature. The tracking itself is not magic. It works because it makes intake visible, which is also why the accuracy limits above are worth knowing.

Sources

• Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 2018; 52(6): 376-384.

• Helms ER, Zinn C, Rowlands DS, Brown SR. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. International Journal of Sport Nutrition and Exercise Metabolism, 2014; 24(2): 127-138.

• Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement: Nutrition and Athletic Performance. Medicine and Science in Sports and Exercise, 2016; 48(3): 543-568.

• Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990; 51(2): 241-247.

• FAO/WHO/UNU. Human Energy Requirements. Report of a Joint FAO/WHO/UNU Expert Consultation, Rome, 17-24 October 2001. FAO Food and Nutrition Technical Report Series 1, 2004.

• National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand: Macronutrient balance. Australian Government, Canberra.

• Burke LE, Wang J, Sevick MA. Self-monitoring in weight loss: a systematic review of the literature. Journal of the American Dietetic Association, 2011; 111(1): 92-102.

• Hollis JF, Gullion CM, Stevens VJ, et al. Weight loss during the intensive intervention phase of the Weight-Loss Maintenance trial. American Journal of Preventive Medicine, 2008; 35(2): 118-126.

• Hill RJ, Davies PSW. The validity of self-reported energy intake as determined using the doubly labelled water technique. British Journal of Nutrition, 2001; 85: 415-430.

• Lichtman SW, Pisarska K, Berman ER, et al. Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. New England Journal of Medicine, 1992; 327(27): 1893-1898.

• Food Standards Australia New Zealand. Nutrients in the Nutrition Panel Calculator: energy factors.

This article is general information only and is not medical or dietetic advice. Speak to your GP or an Accredited Practising Dietitian before making significant changes to your diet, particularly if you have a medical condition or a history of disordered eating.