Weight loss journal

A safe deficit, worked out for two people

The most common rule of thumb is that a deficit of about 550 kcal a day produces a loss of around 0.5 kg a week. It is an estimate, not a measurement of any one person. Our calculators cap the deficit at 300 or 550 kcal a day and never set a target below 1,200 kcal for women or 1,500 kcal for men, because crash plans are the opposite of what a journal is for.

For a 35 year old woman, 165 cm and 68 kg, with light activity, total daily energy is about 1,891 kcal, so keeping weight means about 1,900 kcal and a gentle loss means about 1,350 kcal, above her floor. For a 42 year old man, 180 cm and 90 kg, it is about 2,503 kcal to keep weight and 1,950 kcal for the same loss. The gap between the two shows why copying a friend's number is a poor plan.

Worked on 23 October 2026 with the formulas in our calculators (Mifflin St Jeor 1990, light activity). Estimates for healthy adults, not personal advice.

Twelve weeks at two paces, and what the rule of thumb really says

The 550 kcal a day rule comes from 3,850 kcal a week for about 0.5 kg, which implies roughly 7,700 kcal for each kilogram. It is a convenient estimate, not a law, and real loss usually slows as the weeks pass. With that said, the sums are worth seeing, because they show how little the difference between two plans is in the first month and how much it is by the end.

Arithmetic worked on 23 October 2026 from 7,700 kcal a kilogram. A ceiling on the rule, not a forecast for any person. The 550 kcal pace is about 0.7 percent of the woman's weight a week and 0.6 percent of the man's.

Two details matter for safety. The woman's gentle target of 1,350 kcal sits 150 kcal above her 1,200 kcal floor, while the man's 1,950 kcal sits 450 kcal above his 1,500 kcal floor, so neither plan leaves room to cut further. And if you want to lose 5 kg, the same rule says about ten weeks at 550 kcal a day (38,500 divided by 3,850), which is a reason to plan in months, not days. A doctor can say what pace is right for a body with its own history.

What to write each day, and what to leave out

A journal you keep beats a perfect one you drop. Five short lines a day is plenty: what you ate, what you did, how you slept, how the day felt and one thing that went well. The last one matters because progress is easy to miss when you only look at a number.

Weigh yourself no more often than you can bear. Weight moves from day to day for reasons that are not fat, so a weekly average says more than any single morning. If the scale spoils your mood, stop for a month and rely on how clothes fit and how you feel.

• Write what you actually ate, not what you meant to
• Note hunger and mood, not only quantities
• Count progress in sleep, energy and movement as well as kilos
• If you feel anxious about numbers, stop and talk to a doctor

A week of weigh-ins, and why the average beats the morning

Here is the single biggest thing a journal does for the scale. The weights below are made up to show the method, they are not a real person and not a target. Seven weigh-ins over one week in kilograms: Monday 68.4, Tuesday 67.9, Wednesday 68.6, Thursday 68.1, Friday 67.8, Saturday 68.0 and Sunday 67.7.

Add them up and you get 476.5, and divide by seven for an average of 68.07 kg. The lowest and highest mornings differ by 0.9 kg (68.6 minus 67.7), which is larger than the whole 0.5 kg weekly target, even though nothing dramatic happened. Suppose the next week reads 67.9, 67.5, 68.1, 67.6, 67.4, 67.7 and 67.3. That sums to 473.5, an average of 67.64 kg, a fall of 0.43 kg between weeks. The average moved in the direction you hoped and by about the size you expected, while the single mornings jumped up and down. That is the trend, and it is the number a journal makes easy to see.

• Weigh at the same time, in the same clothes, after the toilet and before food or drink
• Write the number and one word about the day: salty meal, late night, hard walk, period
• Take the weekly average on the same day each week, then compare average to average
• If a week goes the wrong way, read the notes before you change anything
• Treat a month, not a week, as the smallest period that shows a real change

A twelve week plan that does not rely on willpower

A rough structure you can bend. Every step is a habit, not a rule.

1. 1
   Weeks 1 and 2: just record

   Log food, exercise and drinks every day with no changes. You are learning your normal.

2. 2
   Weeks 3 and 4: find one pattern

   Read your days in Tracking. Pick the single easiest thing the record shows, such as a late snack or a skipped breakfast.

3. 3
   Weeks 5 to 8: change one thing at a time

   Use our calorie calculator for a gentle target, and move toward it slowly. Add a walk before you cut a meal.

4. 4
   Weeks 9 and 10: protect the habits

   Look at sleep and mood beside food. A short night often shows up as a hungry next day.

5. 5
   Weeks 11 and 12: review

   Read the whole record. Keep the changes that worked, drop the ones that did not, and decide the next twelve weeks. If progress has stalled, a doctor or dietitian can help.

What is in the app today, and what is not

The position on 23 October 2026.

Feature by feature: the Daily Journal, coaching apps and a paper journal

Where our files did not record an answer for a paid app, the cell says so rather than guessing. The Daily Journal column is what the app does on 23 October 2026.

Sources: the app on 23 October 2026; App Store AU listings read on 20 October 2026; marketplace pages read on 21 October 2026. We do not claim a feature for a paid app that our files do not name.

What weight loss apps and journals cost

App prices were read on 20 October 2026 and paper prices on 21 October 2026. Ranges are a spread of monthly and yearly plans, or of listings, not one price.

Prices change, so check the app's own page before you pay.

The sums on what each route costs

Each range in the table above hides a spread, and the spread is worth reading. Noom ran from A$64.99 to A$309.99, a spread of A$245.00, which is the difference between its cheapest and dearest plan. Simple ranged from A$23.99 to A$99.99, a spread of A$76.00, and Omo from A$14.99 to A$97.99, a spread of A$83.00. Reading the plan names before you pay is therefore worth more than comparing the first number on the page.

MyFitnessPal shows the monthly versus yearly gap clearly: A$29.99 a month is A$359.88 over twelve months, and the A$129.99 yearly plan is about A$10.83 a month, which is 63.9 percent less. Paper is cheaper still: the Amazon AU median of A$17.38 is about 13.4 percent of the yearly MyFitnessPal price, and the eBay AU median of A$29.99 equals exactly one month of its monthly plan. Paper has a hidden cost, which is that it adds nothing up for you, but for a journal whose main job is writing, it is a fair choice.

Which kind of person needs which kind of tool

Match the tool to the habit you will actually keep, not to the one you wish you had.

Patterns, not prescriptions. If you have a medical reason to change your weight, a doctor or an accredited dietitian is the right guide.

Mistakes and myths about weight loss journals

Journals get blamed for things that are really habits of the person holding the pen, so here are the traps we would watch for.

• Myth: weighing daily is the same as tracking. A daily number without an average is noise. Use the weekly method above, and read BMI limits for why one figure is not the whole story.
• Mistake: starting with a crash plan. Targets below 1,200 kcal for women or 1,500 kcal for men are outside what our tools set. The guide to a calorie deficit explains the floors.
• Myth: a bad day undoes a week. One big dinner is a small slice of 3,850 kcal. Write it down and move on.
• Mistake: writing only what went wrong. The last line of each day is something that went well, because progress hides when you only look at a number.
• Myth: sweat or a salty meal is fat. Fluid shifts can move the scale by around a kilogram in a day, which is why the average, not the morning, is the signal.
• Mistake: comparing your week with a stranger's. The same rule gave 1,350 kcal for one profile and 1,950 for another on this page. See how many calories should I eat.
• Myth: you must log forever. Many people log hard for twelve weeks, then lightly, and keep the habit that mattered.
• Mistake: ignoring how you feel. If numbers make you anxious, stop and see a doctor, and read the health disclaimer.

What to look for before you pay

Spending is easier to regret than to undo. Answer these before you enter a card on any weight loss app, and keep the answers.

• Does the price appear in Australian dollars, for monthly and yearly, before you commit?
• What does it renew at after the trial, and where do you cancel?
• Does it set targets below the safe floors, or promise a fast result?
• Is it a diary, or a program you must follow, and which do you really want?
• Can you take your record with you if you leave?
• Does it show adverts, sell your data or share your weight? Read the privacy policy and the terms first.
• Is it aimed at adults, with a clear line about who should not use it?
• Is a free month enough to find out whether you will keep it up? If so, take it.

Free calculators and printables that help

You can do a lot without an app. The TDEE calculator gives the energy you use in a day, the calorie calculator turns it into a target, and the macro calculator and protein calculator split it into grams. The water intake calculator covers drinks, and all of them sit on the calculators page.

On paper, the food diary, meal planner, workout log, sleep diary and gratitude journal are free to download from the printables page. A page of each, kept for twelve weeks, is already a good journal.

Go deeper

For the maths in plain words, read how to calculate TDEE, how to calculate BMI, the BMI chart for adults and activity level explained. Protein is covered in how much protein do I need, and the way we work everything out is on how we calculate and the sources page.

A journal is about more than food. The habit tracker app page covers streaks that allow rest days, the journal app page shows the daily screen, and the meditation app and affirmation app pages cover the mind side. The calorie counter app page has the full day of food added up. See all ten on the journal tools page.

Why coaching apps cost what they do

The largest apps in our read sell a program, not a diary. Noom's listing runs from A$64.99 to A$309.99 because it is built around coaching and a structured course. If you want a plan someone else designs and guides, that price buys it. If you want a diary and a habit, you can start for nothing.

A diary has one more advantage: it asks nothing of you except honesty. No streak shaming and no scores. If you later want a program, your record is ready to bring to a doctor or dietitian.

When a journal is the wrong tool

Tracking food and weight is not safe for everyone. It is not for anyone under 19, who is pregnant or breastfeeding, who has a condition such as diabetes or kidney or heart disease, or who has had an eating disorder or worries about their relationship with food. If any of that fits, please talk to a doctor first.

If you are in distress, support is available at any hour in Australia: Lifeline 13 11 14, Beyond Blue 1300 22 4636 and the Butterfly Foundation for eating concerns on 1800 33 4673. In an emergency call 000.

Tools and guides to pair with a weight loss journal

Questions people ask

Related guides, prices and tools

Where these figures come from

• App prices and rating counts: Noom, Simple and Omo from the Australian App Store, MyFitnessPal from its own page and the App Store, all read on 20 October 2026 and saved in our files.
• Paper journals: Amazon AU and eBay AU first pages of public search results for weight loss journal, read on 21 October 2026 and saved in our marketplace file.
• Resting energy: Mifflin MD, St Jeor ST and others, American Journal of Clinical Nutrition, 1990, as coded in our calculators. The 550 kcal a day for about 0.5 kg a week rule is a commonly used estimate, not a measurement of any person.
• Support lines: Lifeline 13 11 14, Beyond Blue 1300 22 4636, Butterfly Foundation 1800 33 4673.
• Twelve week and five kilogram sums: our own arithmetic on 7,700 kcal a kilogram (3,850 kcal a week for about 0.5 kg), worked on 23 October 2026. A ceiling on a rule of thumb, not a forecast.
• The week of weigh-ins is made up to show the method, with the averages worked on 23 October 2026. It is not a real person's data.
• Spreads and savings: arithmetic on the App Store AU, MyFitnessPal and marketplace figures read on 20 and 21 October 2026.

Updated 23 October 2026. A figure that was not read from a file is written as unknown. Prices change: check the supplier's own page before you rely on one. We are not affiliated with any app named here.