How many calories should I eat per day? It is one of the most important questions that needs to be answered for weight loss. Calories are a part of everyday life. We have all heard of them but do we know the impact they have on our body? You may think that calories are only important to people trying to lose weight. Often we hear of people that try to eat fewer calories or aim to burn more calories with exercise in order to lose weight. It is important to understand that calories are important for everyone.


In order for us to understand how many calories we should eat per day; we first need to understand what a calorie is.



What is a calorie?


In technical terms, a calorie is simply a unit of measurement. It is the amount of energy that is needed to raise the temperature of 1 kilogram of water by 1 degree Celsius. Calories in food provide energy in the form of heat so that our bodies can function. Our bodies store and burn these calories as fuel.


We use calories to measure the amount of energy in everything that we consume, both liquid and solid. Different types of foods, drinks and everything in between will have ranging amounts of calories in them. We all need this energy to live and stay healthy. Everything that we do relies on these calories and our bodies require a certain amount every day to function efficiently and productively.



Calories and weight gain


The reason that people put on weight comes down to one simple factor. They are consuming more calories than they are burning off. When the body is in a state like this, it is in an energy surplus.


It is easy to liken this to scenario to that of a petrol tank in a car. The tank can only fit a certain amount of petrol (calories) and will use this petrol as fuel to operate. When the tank is full, the fuel will overflow. The difference between a car and our body is that we can’t just let the petrol go down the drain. Instead, our body has to store this excess energy as body fat so that it can get burned off at another time. This means that we will be putting on weight any time that we are in a caloric surplus.


The great thing is that if we are in a caloric deficit (consuming less calories than we are burning), we are putting our body in a great position to lose weight.


So how do you make sure that you do not eat too many calories?


First, we need to understand your daily caloric needs (the number of calories your body needs to perform its basic functions and daily physical activities).



Calorie Calculators


Using a calorie calculator is a quick and easy way to determine how many calories your body needs to function on a daily basis. Once you have found this number, it is easy to set some targets around how many calories you should be consuming each day in order to lose weight.


Harris-Benedict Equation


The Harris-Benedict Equation is a simple calorie formula. It uses your age, height, body weight and gender to estimate the number of calories you burn at rest. However, it doesn’t take into account how much muscle mass you have, which means it’s not entirely accurate. It’s still useful in giving you an estimate, and accurate enough to be the best formula to use.



Mifflin St-Jeor Equation


The Mifflin St-Jeor Equation, like the Harris-Benedict Equation, actually has two different equations: one for males and one for females. Both require your age, height and weight as well. In some populations, the Mifflin St-Jeor equation is the best available, according to a July 2018 study published in Frontiers in Endocrinology.



Hint: As both of the above calculators can give differing answers, and they both have their pros and cons, simply complete both of them and take the average between the 2 results.



How many calories should I eat each day to lose weight?


We have now calculated how many calories you need to be consuming on a daily basis. This is the number we need in order to perform basic function. Now we have 3 main options available in order to lose weight.


Increasing your exercise and maintaining this caloric intake means that you will be burning more than you are consuming. This will put you in deficit and as a result you will lose weight. It is a good option for those who are not overly interested in making any nutritional changes.


Decreasing your caloric intake and keeping your current exercise levels the same will mean that you are burning more than you are consuming. This will cause the body to utilise the stored calories in body fat to cover the difference. As a result of this you will lose weight.


How many calories should I reduce each day?


For most people, a calorie deficit of 500 calories per day is sufficient for weight loss and unlikely to significantly affect your hunger or energy levels.


A combination of the above is a dream scenario


This is a fantastic way to lose weight in a manageable and healthy way. Exercising more and working with a calorie deficit will give you optimum results. The most important thing to remember is that you must commit to a lifestyle and not overcommit to too much exercise and too little calories. You must always be working towards a long-term solution not a quick fix.



A final thought…


Not all calories are created equally. It is important to understand that once you have found out how many calories you should eat each day, that you eat the right calories. You should always be looking to consume nutritionally valuable foods. Please know that your body also needs a good balance between all the different food groups.


Sure, it would be possible to stay within your daily caloric needs and eat junk food. Is your body going to be better off for that? Not if it isn’t getting any nutritional value from it.


Always ensure that you have a good balance between carbohydrates, proteins and good fats. Focus on reducing or eliminating bad fats and processed sugars. Always factor in alcohol and liquids in to your daily count as well.


Do all of this and not only will you have a healthy and sustainable nutritional intake, but you will also be losing weight in the best way possible for long term success.



Since COVID-19 entered our lives, we have aimed to deliver some great weekly information as to how you can remain healthy, productive and in good spirits. This blog post is the latest addition to a growing library of information. Click to read more on our dedicated COVID support blogs.


Over the last 4 years Authentic Personal Training has established itself as a leading health and fitness studio on the Lower North Shore. We are incredibly proud to announce that we have been voted The Best Fitness Business on The North Shore for 2019.

Join us on our Facebook page:

To book a complimentary Outdoor Personal Training Session with one of Sydney’s most experienced Personal Trainers, simply fill out the form below

  • This field is for validation purposes and should be left unchanged.


Authentic Personal Training

Personal Training
Group Exercise
Nutritional Advice
Weight Loss
Muscle Tone
Core Conditioning

Studio Hours

Mon - Thurs: 5:30am - 8pm 

Fri: 5:30am - 3pm

Sat: 7am - 12pm

Sun: Closed

Contact Us

Call (02) 8040 5892


Level 1, 22 Willoughby Rd,
Crows Nest NSW 2065 Australia

View map