Height (in cms):
Weight (in kgs):
BMI:

Where BMI becomes more useful is to give you an indication of how much weight you would need to lose (or gain) in order to be at the theoretic ideal weight for a person of your height.

For example let’s assume that a BMI of 22.5 represents your ideal weight.  Then based on the figures you entered, this would mean your ideal weight would be about and therefore you could benefit from losing kgs (go to kg to lb conversion)

When you look at your ideal weight as approximated by the BMI calculation you may feel that you don’t need to lose that much weight. Below enter what you believe your ideal weight is.

Your Target Weight (in kgs)   (You can enter your own target weight here)

This means that you need to lose kgs

How many months will it take you to reach your target weight? 

This means you will need to lose kgs per month.

How do you need to change your behaviour to reach this target?

Some Basic Terms

Kilojoule measures the energy value of both your physical activity and your food. Many of us are also familiar with the term calorie.  A kilojoule equals 0.238 kilocalories (kg to kilojoule conversion calculator)

How many kilojoules do you need to maintain your existing bodyweight?

Firstly, this varies enormously from person to person and under different conditions so the following information is a very rough guide only.  One measure suggests that the average person requires each day 140 kilojoules of food intake for each 1kg of weight.  Using this method if you weighed 80kg you would need 11,200 kj to maintain your existing weight.  To put this in perspective a 1995 nutritional survey by the Australian Bureau of Statistics (ABS) found  “the average energy intake was 11,780 kj for men and 7,790 kj for women classified with an acceptable body weight”.    Based on the information you provided above this would mean your notional kj maintenance level would be

Calculate Notional kj Maintenance Levels for Other Weights

Weight
Daily kj Intake to Maintain Weight

What changes do you need to make to lose your weight?

Now let’s assume that your weight has been constant for a while.  This would assume that your kj consumption has equalled your kj expenditure by way basic body metabolism and exercise.  In order to lose weight you now need to undertake healthy eating practices:

1. Increase your energy expenditure (exercise more)
2. Reduce your energy consumption (eat less)
3. Eat differently by eating differently (burn the fat feed the muscle)

Exercise is important

According to the 1995 ABS study quoted previously you are more likely to reduce weight by increasing your exercise than by reducing your food intake (alone).  The evidence that supported this was that overweight people tended to have a smaller energy intake than people within the normal weight range.   

There are 35,000 kj in each kg of body fat.  So, to lose a kg in a certain time period you need to have your energy expenditure exceed your energy consumption by 35,000 kj.

How much exercise to lose a Kilogram?

Again this varies on the type of exercise, the intensity and the person.  So, for a guide, lets us look at running.

In a steady jog you burn up about 4kj for each kilogram of bodyweight for each km you run.  This means an 80 kg person would burn up about 320 kj for each km they run.  As you can see, a km equates to less than a 100th of a kg.  So you would need to run over 100 kms in a month to lose 1kg.  If you wish to lose the weight over 2 months than it is 50ks per month.

In fact, your results would be better than this because exercise speeds up your metabolism, so that you are burning up the kilojoules faster even when you are not running.  When you are running you are not eating.  And, you probably don’t eat for a while before your run and for a while after you run.  Exercise also releases endorphins so that you feel better.  These factors combined can help you increase your motivation to have a healthier diet. 

Walking a kilometre is almost as good as running a kilometre as far as burning up kilojoules goes.  However, if you are walking it will take you longer to burn up each kilojoule.  See (heart rate monitors) for a more detailed explanation of fat burning zone and other training zones.

Think about this! If you walk or run an extra 3 km a day and these can come in shorter bursts, over a year you could be about 10kgs lighter.  This is a little simplistic because the values used are only approximates and a number of other factors come into play. For example:

• As you train you start to lose fat and gain muscle.  Muscle is heavier than fat, so you will feel and look even better than you would expect from the weight you have lost

• Your metabolism will change

• Your eating habits will change

• Hopefully, you will drink a lot more water.  Did you know that many people confuse hunger with thirst and eat when they are thirsty.  Next time you are hungry have a drink of water and see if that helps your hunger

• Learn more about your training zones

Your Personal Exercise Calculator

Current Weight (kgs)
kgs to be lost	(go to kg to lb conversion)
Months to lose weight
kgs per Month
kjs per Month	(go to a kjs to calories conversion)
kjs you burn up per Km
kms to over per month
kms to cover per day

To see all the calculations together without the commentary in between weight loss summary.

Change your eating habits

You may in fact be able to eat more and lose weight if you change what you eat.  Did you know that a confectionary bar may contain 8 times the Kilojoules of the equivalent weight of fruit.  And, given that the fruit is higher fibre, it will take more energy to digest.

Below are some guidelines of the kjs contained in each 100 grams of various types of food.  The exact kjs per 100grams are listed on the packaging where appropriate.  So you can test these guidelines out.

Food Group	Approx kj per 100g
Bread	1000
Breakfast Cereal	1500
Wheat Rice etc	1500
Vegies	180
Fruit	250
Cheese	1400
Meat	1500
Eggs	600
Fish	750
Poultry	600
Butter & Margarine	750
Canned fish	400
Sweets	2000

Calorie Counter

To obtain a ball park estimate of you daily kj consumption complete the following table.

Enter the number of estimated 100 gram servings you have of each food group

So your approximate kj from the above food groups is

Bread
Breakfast Cereal
Wheat Rice etc
Vegies
Fruit
Cheese
Meat
Eggs
Fish
Poultry
Butter Marg
Canned fish
Sweets
TOTAL

How Much from Drinks?

Kjs per 100 mls

The table below contains rough approximations of the kjs in 100mls of various drinks.  You will notice that most drinks are around 2 kjs per ml or 200 kjs per 100 mls or 2000 kjs per ltr.  These approximations may be a little on the high side.

When judging how to balance your drinks it is important to appreciate that the kj content is not the only criteria.  Obviously, the nutritional value of some items (eg Fruit or Vegetable Juice) is much higher than other items (eg beer or soft drink).  This also highlights the importance of drinking ample fresh water each day. 

Other

Sugar contains about 60kj per teaspoon.

The Magic Formula to Weight Loss

We have worked through the basic mathematics of weight loss - you need to exercise more than eat. But is it that straight forward, you may be wondering are there other factors that can help me accelerate my weight loss.  We have heard about diets that claim they can increase your weight loss rate.  There has been the Atkins diet, low carb diets and low fat diets. There are even diets where you can  eat more and lose weight.  Now we have improved our understanding of diet sufficiently to understand that it is not just the amount of food we eat or the type of food we eat but also the combinations of foods we choose.  Some of these factors are quite basic. For instance - if you ate a fruit salad for lunch you may still feel hungry after your lunch.  However it you were to add some yoghurt to your fruit salad (and therefore add protein to your meal) you may have a greater sense of having your hunger satisfied.  Give this a try and see what difference it makes to you.

You can modify your diet to take advantage of fat burning techniques and improve your understanding of rotating your eating and when you do these things the calculators you used above will tend to underestimate your weight loss.  In losing weight it is important also to make sure you are healthy.  Certain types of health issues can cause you to hold onto weight. For instance an underactive thyroid can slow down your metabolism and therefore you rate of weight loss. So if you are not losing weight as quickly as you expect visit your doctor.  Thank you for visiting the long term weight loss guide.  Come back again to check on your progress.