How many kilojoules per day to lose 1kg per week?

Want to lose 1kg a week? Here’s how many kilojoules you need to eat per day.

1 kilogram a week. It seems like a reasonable amount to want to lose, particularly if you have 20, 30, 40 or even more kilograms you want to say goodbye to forever. But how many kilojoules should you be eating to lose 1kg a week, and is that type of consistent weight loss both possible and practical? Let’s take a look.

What’s a kilojoule?

Firstly, before we start looking at how many kilojoules it takes to lose 1kg a week, it’s important to understand exactly what a kilojoule is. Essentially a kilojoule is a unit of energy, the same way as a calorie is. The only difference is that kilojoules are metric units of energy, and calories are non-metric units. Eat something that contains 420 kilojoules (or 100 calories) and you’ll have 420 units of energy at your disposal – yours to use throughout your normal day for activities like walking, running, eating, sleeping, and so on. Take in more energy than you need, and your body will store the excess energy as fat. Take in too little, and your body will use the energy from its fat stores to keep you going – which is exactly how you lose weight.

So how do you get your body to start using the energy from its fat stores so that you can start losing your 1kg per week? Two words. Kilojoule deficit. Reducing your energy intake so that you’re burning more kilojoules than you’re actually using. Once you start creating a kilojoule deficit, you’ll start losing weight. The only question that remains then, is how much do you reduce your kilojoules by in order to lose that magic 1kg number?

How to lose 1kg a week

Calculating how many kilojoules a person needs to eat to lose 1kg a week can be tricky. Firstly, everyone’s physiological makeup is different, and everyone responds to nutrition and exercise in different ways. In addition, gender, age, and activity level also play a role.

Generally speaking, however, if you’re looking to lose weight, you should be aiming to reduce your kilojoule intake by 2 100kj in order to lose up to 1kg a week. On average, a moderately active man between the age of 18 and 50 needs to take in 12 200 kilojoules a week to maintain his weight, while a moderately active woman of the same age would need to take in 9 250 kilojoules a week for maintenance. Reduce this amount by 2 100, and that’s the average amount of kilojoules needed (7 150) to lose between 0.5 and 1kg a week. Continue this trend over time, and you’ll have the consistent kilojoule deficit you need to get you to your ultimate weight loss goal.

Eating to lose weight

Want to start creating that kilojoule deficit right now? Then you’ll need to concentrate on your plate, as typically weight loss is primarily driven by optimal nutrition. While you want to reduce your kilojoules so that you’re burning more energy than you consume, you don’t want to reduce your intake to the point of starvation. Start by lowering your intake to 7 150 kilojoules a day, and reassess after two to three weeks to see if it’s the right amount for you, or if you need to create a bigger or smaller deficit to help your weight loss.

It’s also important to remember that whether you’re eating to lose 1kg a week, or you’re simply eating to be healthy, making positive nutrition choices doesn’t have to be about punishment or deprivation. Load up on lean protein, healthy fats, whole grains, fruits and vegetables, so that you stay fuller for longer, and avoid refined, processed, and convenience foods. The more interesting and flavourful you can make your meals, the more likely you’ll be to stick to a healthy eating plan – and lose your 1kg a week along the way!

Training to lose weight

While it’s generally agreed that nutrition is the most important factor when it comes to healthy, sustained weight loss, if you want to burn more kilojoules in order to lose 1kg a week, exercise can be a helpful tool as well. Not only can it increase your kilojoule deficit, it can help make you fitter and stronger, and preserve your lean muscle mass too.

If you’re just starting out, aim for two to three sessions of 30 minutes each per week, and increase the frequency and intensity of your training the fitter you become. Cardiovascular exercise, like brisk walking, running, boot camps or aerobics are great for burning off kilojoules, while weight training is excellent for building lean muscle, that in turns speeds up your metabolism and helps boost your weight loss. Try different forms of exercise like high intensity interval training, powerlifting, Crossfit, yoga, Pilates, Zumba and more, see which types of training you connect with the most, and start incorporating them into your exercise routine. And remember that when it comes to working out, there’s only one rule – have fun!

Should you be losing 1kg a week?

Now that you have an idea of exactly how many kilojoules you need to be eating to lose 1kg a week, and you know how to create a kilojoule deficit, it’s time to look at the most important question of all – should you be losing 1kg a week in the first place?

While one kilogram may not seem that much, particularly if you have a significant amount of weight to lose, in fact the recommended amount of healthy weight loss sits at between 0.5 and 1kg per week – meaning that if you’re looking to lose 1kg a week, you’ll be needing to hit that maximum weight loss target week in and week out. And while this may be relatively easy when you start out, sustaining a kilojoule deficit this large for a prolonged period of time can be difficult, and potentially harmful as well.

Cutting out the 2 100 kilojoules needed to lose upwards of half a kilogram a week is challenging enough; doubling this to a 4 200 kilojoule deficit in order to lose a full kilogram can leave you feeling unhappy and unsatisfied, not to mention craving all the wrong foods as well. What’s more, physical fatigue could leave you too tired to train, with your aggressive kilojoule cut possibly resulting in the loss of lean muscle, rather than actual fat.

To avoid these damaging side effects, and to ensure healthy living inside and out, it might be best to readjust your goal from 1kg a week to ‘up to’ 1kg a week. Losing upwards of 500g a week is a far healthier, far more sustainable goal, and will ensure you enjoy the process as you go – which will ultimately result in you staying the course for longer, and achieving your desired end result.

Play it safe for the sake of your mind and your body. Set yourself a reasonable, achievable goal, plot your kilojoule intake, plan a weekly meal template of healthy, nutritious choices, put a workout routine in place, and start doing what it takes to lose up to 1kg a week, every week until you meet your target. The time will pass anyway – so why not use every moment of it to start making your dreams of living your best life come true!

All the information detailed here serves as a guideline for healthy eating and weight loss. Please ensure to always visit a doctor, dietician or other qualified individual before changing your diet and exercise routine. For more information, please refer to our site disclaimer.