What is a diet?
Nearly two thirds of Australians are overweight or obese. Carrying extra weight increases your risk of chronic diseases like heart disease and stroke, type 2 diabetes and some cancers. If you are above a healthy weight, losing just a few kilos can lower your risk of health problems.
To lose weight, you need to eat and drink fewer kilojoules than you use. (A kilojoule (kJ) is a measure of the amount of energy a person gets from food. The average adult will burn about 8,700kJ per day, although the amount varies depending on age, gender and level of activity.)
A weight-loss diet restricts what you eat so you lose weight.
A 'fad' diet is an eating plan that often promises rapid weight loss but is not based on science. Often, fad weight-loss diets want you to cut out entire food groups. This could mean you don’t get all the nutrients the body requires.
They should not be confused with vegetarian or vegan diets. These are not weight-loss diets and, with good planning, vegetarians and vegans can get all the nutrients they need.
It's important to choose an eating and exercise plan that is healthy and that suits your lifestyle. Following a healthy eating plan is better for your health and will mean you are more likely to keep the weight off long term.
The risks of fad dieting
The weight-loss industry is worth more than $635 million in Australia. However, it is important to realise that not all diets work and some can also be potentially harmful. Going on a very restrictive fad diet can lead to:
- slowing of the body's metabolism (how quickly you burn kilojoules), meaning you will put on weight more easily in future
- constant feelings of hunger, leading to food cravings and an increased appetite
- rapid weight loss followed by rapid weight gain
- an eating disorder, such as anorexia nervosa or bulimia
- less muscle tissue and lower bone density
- headaches, insomnia and fatigue
- lower body temperature
- constipation and/or diarrhoea.
Most of the weight you lose on a fad diet is water and lean muscle, not fat. That's because when you eat too little, your body breaks down muscle to get enough kilojoules. It is easier for your body to get kilojoules from muscle than from fat.
To maintain a lower weight permanently, it is better to change your eating behaviour in a way you can keep up long term.
How to spot a fad diet
Fad diets are very popular in Australia. Common fad diets include those that recommend cutting out sugar, drinking meal replacement shakes, following a low carbohydrate/high fat diet, detox diets, the raw food diet and the Dukan diet.
Avoid a diet that:
- promotes very fast weight loss (without supervision by a dietitian and a doctor)
- focuses on short-term changes to your eating or exercise
- includes pills or preparations.
How to lose weight healthily
- different coloured vegetables
- whole grains
- lean meats and poultry, fish, eggs, tofu, nuts and seeds, and legumes/beans
- milk, yoghurt and cheese, mostly reduced fat.
You should also drink plenty of water, and limit your intake of foods that contain saturated fat, added sugars, added salt and alcohol.
Tips for losing weight
- swap foods high in fat, sugar and salt with foods from one of the 5 healthy food groups
- cut down on takeaways - eat leftovers from last night's meal instead
- eat regularly and plan ahead with healthy snacks
- choose smaller portions
- eat breakfast
- enjoy a wide variety of foods
- exercise for 30-60 minutes every day
- eat plenty of fibre to fill you up
- eat more vegetables.
Last reviewed: June 2017