Energy Restricted Diets
There are many approaches to kilojoule restriction for weight loss or to prevent weight gain. Kilojoule restriction is achieved by making changes to someone’s usual daily food intake.
Some changes are easier to stick with but result in slower weight loss, whereas others are more difficult to stick with but provide more rapid weight loss. The video below explains what some of these methods are.
For weight loss, we need to create an energy deficit.
This means we either reduce the number of kilojoules we eat below what we need for weight maintenance, or we increase the number of kilojoules we burn.
There are a number of ways that you can reduce total daily energy intake to achieve weight loss.
Reduced Energy Diets (or REDs)
Reduced Energy Diets (or REDs) identify ways to reduce a person’s current eating habits by 2000 – 4000 kilojoules each day.
They usually involve swapping energy dense foods for low energy density foods and by managing portion sizes of foods and drinks.
Reduced Energy Diets have the highest adherence in the long term which means more sustainable weight loss, however weight loss is slower than when following other strategies.
Low Energy Diets (or LEDs)
Low Energy Diets (or LEDs) use daily energy intake targets between 4200-5000kJ.
This usually involves following a prescribed diet plan, such as those found on web-based programs or home delivered, pre-prepared meals.
Low Energy Diets usually result in low to moderate adherence but can take the hassle out of planning and cooking meals.
Very Low Energy Diet (or VLED)
A Very Low Energy Diet (or VLED) has a very low total daily energy intake target.
People are guided to consume between 1800-2500kJ per day.
This is usually achieved using formulated meal replacements, often in the form of shakes or bars.
VLEDs cause rapid weight loss and are often low in carbohydrate.
It is recommended that they only be used under medical supervision by a doctor and/or a dietitian.
The advantages of VLEDs are that they are useful for when rapid weight loss is required e.g. pre-surgery.
The disadvantages are that they are hard to adhere to due to their large energy restriction and allow very little food intake and variety.
People following a Very Low Energy Diet may also experience light-headedness, fatigue, headaches and bad breath.
Note: People on a VLED are guided to consume 2500 – 4000kJ a day. The VLED figures in the video are in the lower range. If you are on a VLED, your doctor or dietitian will advise what is best for you.