Weight loss is simply about taking in less kilojoules than you burn. However, after years of bad habits it can be hard to change your ways. There are now a range of treatments to help you to reduce your energy intake. Talk to your dietitian about the best choice for you.

Energy Intake

Energy is measured by ‘kilojoules’ (or calories in America). Kilojoules come from four different sources:
Carbohydrates – 16kJ/gram
Protein – 17kJ/gram
Alcohol – 29kJ/gram
Fat – 37kJ/gram

Although we need carbohydrates, protein and fat to survive, you can see the benefit of having a low fat diet as fat provides double the amount of kilojoules per gram as carbohydrates or protein do. Most people only need approximately 20g of fat each day, yet a Big Mac provides 25 grams of fat alone!

And, as alcohol is so high in kilojoules, and isn’t needed for nutrients, if you are trying to lose weight, it should be consumed on special occasions only.

Energy Expenditure

We expend energy in four different ways:
Basal Metabolic Rate – everyone burns kilojoules each day through our BMR. Even if you are lying unconscious in a hospital bed, you still need to be fed (via a tube) so that you get enough kilojoules to feed your BMR. Your BMR depends on a range of different factors including your height, age, muscle mass, sex, amount of physical activity, genetics and a range of other factors.
Thermogenesis – how effectively your body regulates your temperature. This also depends on a wide range of factors such as genetics and muscle mass.
Incidental Activity – You burn kilojoules going about your day to day activities. People who fidget more and move around more, burn more kilojoules than people who work in sedentary occupations. So, to lose weight, move around as much as you can.
Planned Exercise – Planned exercise is when your heart rate is elevated for an extended period of time, for example, going for a jog, playing netball or doing a work out at the gym. Exercising burns kilojoules at the highest rate. It also increases your BMR. You should aim to do at least 30 minutes of planned exercise each day, or more to lose weight.

Low kilojoule diets

Your dietitian will be able to calculate how many kilojoules you are consuming each day, and will recommend how many kilojoules you should consume each day to lose weight. You need to consume at least 5,000kJ each day for your diet to be nutritionally complete.

It is essential that your dietary intake is nutritionally complete. This is the problem with many of the diets that you see in magazines and on the internet. If your diet is not meeting your nutrition requirements, you will crave more food, as your body will crave the nutrients that it is missing. These diets can also lead to nutritional deficiencies and health problems. Avoid any diet which cuts out any of the 5 core food groups. The 5 core food groups are:
Breads & cereals
Meat & meat alternatives.

Hints to decrease your caloric intake

Hints to decrease your caloric intake include:
Cut out alcohol
Reduce your fat intake
Ensure you include plenty of vegetables as they are very low in kilojoules and will help to fill you up
Avoid high kilojoule drinks such as juice, soft drinks and cordial
Weigh foods to ensure that you are not over-estimating portion sizes.


The more exercise you do, the more kilojoules you will burn. You may be better off doing a little exercise each day, than only doing it a couple of times each week, so schedule some time for exercise daily. You need to aim to do exercise that increases your heart rate. You should feel a bit warmer, your heart beating a little faster and maybe some puffing. Try to choose exercise that you enjoy so that you are more likely to do it.

Ideas include:
Get a casual job delivering mail to make a bit of money on the side
Join a team such as a netball, soft ball or basketball team
Have a hit of tennis/squash with a friend
Exercise with your family – play beach cricket, go for a bike ride or go hiking
Take a class – try yoga, pilates, water aerobics or kick boxing
Learn self defence.

Meal Replacements

Meal replacements are specially formulated shakes, bars and soups which are high in nutrients and low in kilojoules which can be used to replace meals. Meal replacements can be an effective tool to help people lose weight quickly, whilst still getting the nutrition that they need. The problem with meal replacements is that they are a short term fix, and unless you modify your eating habits, you will regain the weight when you stop using them. Research shows that meal replacements used under the guidance of an Accredited Practising Dietitian can result in effective long term weight loss. There are a variety of different meal replacements available on the market – ask your dietitian which are the most suitable choice for you.

Advantages of Meal Replacements
Low in kilojoules

Disadvantages of Meal Replacements
May become monotonous after a while
Unsocial as it’s not much fun going out to lunch with friends and having a meal replacement
May result in short term side effects such as bad breath or constipation
Only a short term solution unless you learn to change your eating habits as well.


Pharmacotherapy is the medical term for weight loss medications. As research continues, more and more weight loss medications are being released onto the market. Your dietitian will be able to provide you with up to date information on the latest medications available.

The most common weight loss medications available on the Australian market at the moment are:
Orlistat – causes your body to malabsorb fat
Phentermine – a type of amphetamine which suppresses appetite
Metformin – suppresses glucose production and decreases appetite
Exenetide – an injection for people with diabetes which also results in weight loss.

All of these medications should be used under the guidance of your dietitian as they will only produce results whilst you stay on them, and taking them long term can cause other side effects and significant damage to your hip pocket!

There are also a number of medications available over the counter. These contain a range of active ingredients, such as green tea leaves and guarana designed to suppress the appetite, however most have only got small amounts of these active ingredients (which is why they are available over the counter!!) and work more by placebo than actually altering your hormones.


There are also a number of weight loss devices which are now becoming available on the market which work to reduce your intake of food.
Portion control plates – help you to serve smaller portion sizes
Smart mouthguards – cause you to chew your food more slowly so that you become more aware when you are full
Intra gastric balloon – a balloon is inserted into your stomach to help you feel fuller faster
Endobarrier – a device which is inserted into your bowel and affects appetite hormones.


Surgery is recommended for people with a BMI over 35 (or 30 in conjunction with co-morbidities such as diabetes or sleep apnoea). There a numerous options, but the most popular choices are:
Laparoscopic adjustable gastric band surgery – an adjustable band is placed around the stomach, forcing you to slow down your pace of eating,
Sleeve gastrectomy – two thirds of the stomach is surgically removed to make a ‘sleeve’ thereby reducing the volume of food which can be eaten at any one time, and
Roux-en-Y Gastric Bypass – this operation works in three different ways. Firstly, the stomach is stapled to create a small pouch causing a reduction in portion sizes, secondly, the part of the stomach which produces ghrelin (an appetite inducing hormone) is removed to decrease hunger and thirdly, part of the bowel is removed so that foods high in sugar or fat are malabsorbed.

Remember all of these options are just tools to help you lose weight in conjunction with behavior change – there is no such thing as a miracle cure!