Medicare Local have come out swinging against fad diets, which Ms Melmoth said appear to produce results, but can have long-term damaging effects.

"Fad diets are difficult to maintain, are usually poorly researched and can often cause more harm than they help," Ms Melmoth said.

"Many fad diets are also based on poor research or no research at all, which can be alarming particularly if they are promoting unhealthy practices as healthy ones. For example a high fat diet is amongst the current fad diets, promoting consumption of fats such as butter or coconut oil. There is minimal research to prove that there are any health benefits to this type of diet however there is a large amount of evidence that links a diet high in saturated fat, found in butter and coconut oil, with heart disease."

Fad diets usually have some element of restriction or exclusion of certain food groups or unrealistic restriction in energy intake. on

Because of this, they're difficult to stick to and often set the participants up for failure as they are focused on short-term results rather than long-term healthy lifestyle changes.

"Fad diets most commonly promise fast results - something that many busy Australians are looking for when it comes to weight loss. The problem with these quick results is that they are often coming from an unrealistic practice that is difficult to maintain long term and more often than not result in a regain of the weight that is lost, plus some," Ms Melmoth said.

"Fad diets are also popular due to their promotion by celebrities and well known chefs. People see these public figures following a certain diet or lifestyle and aspire for the same results, however these diets are often based on personal choice of the celebrity or are hand-picked to advocate the next money-making venture rather than promoting evidenced-based health benefits."

She said it's important to seek out credible sources before making any dietary and lifestyle choices.

"There are a lot of people giving advice in this area however they are often unqualified to give out such advice. At this stage there is little to no research into these diets to suggest that they are viable, healthy options. As an accredited practising dietitian it is my job to provide health advice based on very well researched information that has a large evidence base to support it and the associated health benefits," Ms Melmoth said.

"Nutritional deficiency is a concern with fad diets that restrict one or more food groups. There are issues with promoting certain food groups over others for example a high fat diet which can ultimately lead to heart disease.

"There is also cause for concern when fad diets are applied to whole families as they can be harmful to the growth and development of children, especially if they are not getting all the nutrients they need.

She said we also need to be mindful of how constant fad-dieting or 'yo-yo' dieting can affect our mental health.

"It can be very discouraging to continually lose and regain weight as happens with 'yo-yo' dieting and this may ultimately effect self-esteem and sense of self-worth," Ms Melmoth said.

Unfortunately, there is no special diet or quick fix solution to weight-loss - but Ms Melmoth said you can make and maintain healthy lifestyle choices by following the Australian Dietary Guidelines.

"These guidelines are put out by the Australian government and have a large amount of research backing them. These guidelines include information around how much of each of the five core food groups we need for good health based on our age and gender," Ms Melmoth said.

"They also provide practical advice for achieving a healthy lifestyle. Healthy lifestyle changes may appear to take longer to make but are much more beneficial to health in the long run and can be maintained more easily long-term."