Formulas for weight loss

The Aussielent meal plan calculator uses a practical and effective approach to weight change.  Whether you're looking to lose or gain weight, the approach is similar, so let’s dive in and we’ll explain how our calculator works.

Basal Metabolic Rate

We start by considering the number of calories your body uses at rest for its normal metabolic functioning.  Even at rest your body’s organs use energy constantly to maintain its basic functions - your liver, brain, kidneys and heart are all major users of energy provided by the foods you eat.  This energy expenditure is called your Basal Metabolic Rate (BMR) and generally accounts for 70% of the average person’s total energy expenditure. 

The basal metabolic rate for people varies considerably depending on a person’s current weight, height, gender and age.  It can also be affected by other factors such as ambient temperature, your stress levels, and your current health status (if you're currently sick). Intuitively it makes sense that at rest a 21-year-old male who is 180cm tall uses more energy than a 55-year-old woman who is 162cm tall.  The actual BMR formula that we use - called Mifflin St Jeor - has been proven to provide good estimates across all ages, heights and gender.

Activity Level during the day

Once we have calculated your BMR we next consider your activity levels throughout the day.  Jobs that require physical exertion such as builders, gardeners or couriers use more calories during the day than IT developers or accountants who are sitting while they work.  Jobs in retail or nursing can be dependent on the specific employment situation as to how much activity is performed during the day.  We have provided some indicators on how to assess your activity levels, but the reality is in Australia, the activity level of our jobs is generally sedentary or light. Even construction work that traditionally had a lot of activity is now commonly supported by machinery to do the heavy lifting.

We recommend you carefully consider the amount of activity you perform during the week. Trial the calculator at different activity levels (for example light and moderate) and consider how that impacts the overall meal plan results and the plan you choose to go with.  Our meal programs don’t require strenuous exercise programs to be effective however we do recommend at least 20-30 minutes of walking per day. 

Aussielent Meal Plan calculations

Once you have input your details into the calculator and hit the submit button, we will present you with our recommended meal program.  The key number of the program is the overall calories per day.  This recommendation is developed by calculating your daily energy expenditure (a calculation of your BMR and activity level) and then we reduce or increase your daily calories by at least 500 calories.  We find 500 calories is a practical number that balances diet results with diet sustainability. 

Our calculator will provide you with an estimated number of weeks it will take to hit your weight goal if you follow the recommend calories per day.  It’s exciting to see that weight change is achievable.  You should come back regularly and check in with the calculator to see how you are tracking to the plan and also remember there are many variable factors in weight change and some of these are discussed in our article ‘why can’t I lose weight?’.

The Aussielent meal plan presented to you as a recommended program shows you how Aussielent products can be used in your overall meal program. Aussielent products are an affordable and simple option to ensure you maintain your diet plan and keep on track.  We have some other recommended articles to support your meal program including ‘good snacking’ and ‘recommended main meals’.

Here’s to heathy eating,

Cheers, Paul.



We use your data to estimate your body’s basal metabolic calories.

We then apply an activity factor and subtract 500 calories to present your recommended weight program.

We find 500 calories is a practical number that balances diet results with diet sustainability.