How exact does calorie and macro tracking need to be?

Close and steady works better than exact. Every number in the chain is an estimate: the label, the food values, your portion, the figure for what your body uses and a watch’s count for a workout. What moves the result is landing inside a range on most days and logging on most days, with the most care on two numbers: energy across the week, and protein on most days.

Every number is an estimate

The figure you aim at is an estimate before you eat anything. In a systematic review of the equations used to predict resting energy, the best one, Mifflin-St Jeor, came within 10% of the measured value for more people than any other. That still leaves room either side for any one person. US rules allow a packet’s true calories to be up to 20% above the label, and how accurate calorie counts are covers menus, diaries and photos.

Watches are further off. In a 2017 lab test of seven wrist devices worn by 60 people, none estimated energy burned with less than 20% error.

So a daily target to the single calorie is more exact than anything that feeds it. A range is the honest shape for a target.

In Nume: your day’s plan is a range, for example 1,920 to 2,160 kcal and 120 to 150 g of protein. Each meal is planned as a range too, and Profile shows each number with the reason behind it. The activity of your usual week is already in your daily energy, so there is no watch figure to add and nothing to eat back.

How much does a small miss matter?

Once, very little. A model of human metabolism published in The Lancet found that a lasting change of about 24 kcal a day leads to about 1 kg of weight change in the end, with half of it reached in about a year. On that model, eating 100 kcal over plan every day comes to about 4 kg in the end, about 2 kg of it in the first year. One big meal barely shows. See why the scale may not be moving for how weight moves within a week.

What counts is a small miss you repeat without seeing it: a pour of cooking oil that has grown, or a daily snack that never gets logged.

In Nume: a meal a little over or under its range changes nothing. Nume looks again at the meals ahead when a meal runs more than 15% outside its range, when a meal’s protein falls under 70% of its planned minimum, when the day runs more than 15% outside its own, or when an extra comes to 250 kcal or more. If the day needs it, the rest of today changes and says why, and tomorrow stays as it was.

Logging often beats logging exactly

In a 24-week online weight-loss programme with 142 people, those who lost 5% or 10% of their weight opened their food log more times a day than those who didn’t. They did not spend longer logging, and the time it took fell from about 23 minutes a day in the first month to about 15 by the sixth.

In a small three-month pilot trial of 38 people, one group logged everything they ate and drank. The other only ticked their high-calorie foods on a checklist. The checklist group logged on 97% of days against 49%, and the two groups lost about the same: 3.3 kg and 3.4 kg.

In Nume: a meal eaten as planned is one tap, “Had this”, already counted. When it went differently, a quick log is one of five choices, from much lighter to much heavier than planned. A photo or a line fills in every part when you want the detail.

Which numbers deserve care?

Energy across the week. The International Society of Sports Nutrition (ISSN) position on diets says fat loss is driven by a sustained calorie deficit, and that diets from low-fat to low-carb can work similarly well. The week’s total is what moves your weight.
Protein on most days. In a review of 49 trials of protein supplements alongside lifting, muscle gains levelled off at about 1.6 g per kg a day. So 10 g under on one day changes little. Under on most days does. See how much protein and the protein calculator.
Carbs and fat can move with your tastes.
Fibre is a guide to aim near, covered in how much fibre a day.

In Nume: each meal is planned with an energy range and a protein range. Every meal you log with a photo or a line also shows its carbs, fat and fibre. Progress reads protein as the days you landed inside your plan, such as “Inside your plan on 5 of the 6 complete days”, and averages start after three complete days.

When does more detail help?

A short spell of closer logging pays off when the scale hasn’t moved for three or four weeks, with big plates, with cooking oil and when eating out (what to order when you eat out).

The closer you are to your goal, the more a small miss counts. On a cut of 300 kcal a day, a steady 100 kcal miss is a third of the gap. That is why the last stretch to a six pack takes more care than the first. If the scale is flat but your clothes fit differently, you may be losing fat and building muscle at once.

In Nume: any part of a meal can be corrected in household amounts, or you can say how much of the plate you had, and how Nume estimates a meal covers the rest.

Steady tracking with Nume

Nume is built for close and steady. Your day is a range worked out from your body, your usual week and your goal, and it follows your latest weigh-in. Planned meals show a range. Logged meals show one figure with ”≈”, to the nearest 10 kcal, so you can see how firm each number is. Small misses are absorbed, and a real difference reshapes only the rest of that day. Your weight is compared with a weigh-in at least 14 days earlier, so one heavy day doesn’t read as a setback.

If you or your coach have your own number, Nume plans 5% either side of it. If numbers aren’t for you, switch them off in Profile > Numbers. Today, your meals and Progress then leave them out, Nutrition today keeps them, and the plan runs exactly as before.

See how Nume works across a day, or start from the calorie calculator.

Common questions

Is 100 calories over a big deal?

Once, no. Every day, it adds up to about 2 kg in a year on the Lancet model above.

Do I have to hit my macros exactly every day?

No. Aim for energy across the week and protein on most days. Carbs and fat can follow your tastes.

Should I eat back exercise calories?

In that lab test, no wrist device was within 20% for energy, so eating back a watch figure adds that error to your day. Nume counts your usual week’s activity in your daily number already.

Can I lose weight without counting?

Yes, with a plan to follow and a quick way to say how each meal went. In the small checklist trial above, people who only ticked high-calorie foods logged on far more days and lost about the same as those who logged everything. That is how Nume runs with the numbers switched off.

Checked on 12 November 2026 · The Nume team