Key points
  • Fad diets are based on little scientific evidence. They promise quick and easy weight loss or considerably improved health.
  • Rigid food rules and blaming certain foods, food groups or nutrients as the cause of weight gain are common themes of fad diets.
  • Fad diets rely more on a ‘one-size-fits-all’ approach.
  • Instead of scientific evidence, fad diets make claims based on testimonials.
  • Health risks from following a fad diet include nutrient deficiencies, fatigue, weight regain and disordered eating.
  • The best approach to weight loss and health is to follow a long-term, healthy and balanced eating plan and to keep active. A dietitian can support your weight loss goals with a personalised eating plan.
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A fad diet is an eating plan that often promotes quick and easy weight loss or radically improved health.

Fad diets can be tempting as they offer a quick fix to either real or perceived problems. But they have little scientific evidence to support their claims.

Like all fads, different diets go in and out of fashion. There are always new diets emerging to replace the previous ones that failed. Sometimes these diets seem to work for a while, but often their success is short-lived. Then another diet takes the spotlight.

Thanks to social media, the reach of fad diets has grown. Influencers and celebrities can have a dramatic impact on large audiences by promoting so-called 'easy solutions'. Yet the quality of their advice is often highly questionable and potentially unsafe and harmful. Trusted nutrition advice is best given by a qualified dietitian.

Woman searching food on her mobile sitting next to husband and baby.

How to recognise a fad diet

Every fad diet is unique in how it is promoted. Some restrict fats or carbohydrates. Others limit serving sizes. Others focus on food combinations or specific foods that need to be eaten or avoided.

They are generally difficult to follow as they are not based on usual eating patterns. They are generally not scientifically supported with little evidence behind them.

Fad diets will often:

  • give restrictive options for what foods are allowed or not allowed to be eaten
  • ban or demonise certain foods as being the cause of weight gain and ill health
  • promise quick and easy weight loss with little effort
  • ignore dietary recommendations or even blame dietary guidelines for health and weight problems
  • recommend using a single food consistently as the key to the diet’s success
  • claim specific foods can ‘burn fat’
  • focus only on your appearance rather than on health benefits
  • recommend 'detoxing' or avoiding foods in certain combinations
  • use mostly testimonials as evidence of the diet’s effectiveness
  • are endorsed by celebrities or celebrity doctors
  • recommend the same diet for everyone without accounting for specific needs
  • require expensive supplements, shakes and pills.

Examples of fad diets

There isn’t a complete agreement on what diets are and are not fads. The table below lists examples of some of the more popular diets that have been considered fads.


Examples of fad diets
Diet Premise Main issues

Alkaline diet

Eating acid-producing foods (meats, grains and dairy) leads to an acidic environment in the body, metabolic imbalance and disease. Replacing these foods with alkaline foods (fruits, nuts and vegetables) makes the body more alkaline and restores good health

Food has little effect on the pH of the blood – our body can balance this naturally

Parts of the body (like the stomach) need an acidic environment to digest food

Needlessly excludes healthy foods such as wholegrains. Little evidence to support any of the claims

Carnivore diet

Only includes meat, fish, chicken and other animal foods. Claims humans are designed to only eat these foods and blames plant-based foods as the cause of our modern health problems

Excludes all fruits, vegetables, legumes, grains, nuts, and seeds which are all linked to good health

Very low in calcium, vitamin C and fibre

Long-term concerns to do with cancer and heart disease

Eat Right 4 Your Type (Blood Type Diet)

Your blood type (A, B or O) determines which foods you should or should not eat based on how your body responds to and digests certain foods

Food groups or individual foods are needlessly excluded randomly based on a person’s blood type

No scientific evidence on the relationship between blood type and food choices

Primates have a range of blood types like humans, but all eat the same types of foods further debunking the diet’s premise

Paleo diet

Our body is designed to run optimally by eating in the same way as the assumed eating patterns of our Palaeolithic ancestors

Evolutionary arguments don’t hold up

Needlessly excludes healthy high-fibre grains and legumes

Has an unhealthy focus on ‘good’ and ‘bad’ foods

It can be expensive and is hard to maintain because of its strict food rules

Wheat Belly

Lose weight and reverse health problems by eliminating all forms of wheat. Blames gluten as the culprit for weight gain and many modern health problems

Highly restrictive diet that cuts out many types of wholegrains – foods linked to good health and a valuable source of nutrients

Limited research to support the claims made about the diet

Weight loss on the diet isn’t from removing gluten and wheat from the diet, but from following a lengthy list of food rules


A 30-day elimination diet that removes all grains, dairy, soy, legumes, sugar, alcohol, and certain preservatives. Blames these foods as the cause of most modern health problems. After 30 days, begin to reintroduce some foods

Very restrictive diet that cuts out many foods linked to good health

Strict and regimented in its food rules that are not sustainable and which creates an unhealthy relationship with food

Difficult to follow in social situations

Not all diets are fads

Diets that may have been considered fads in the past can gain acceptance as scientific evidence evolves to support their adoption in certain situations. Very-low-carbohydrate diets are one example. A person with diabetes may choose to follow it to help manage diabetes with the support of a dietitian.

Very-low-energy diets (VLEDs) are another example that when done under appropriate supervision and for medical or health reasons, they can work to help achieve more dramatic short-term weight loss.

And the evolving trend of intermittent fasting may be seen to be moving out of the area of 'fad' as scientific evidence builds that it can represent a viable option for some people.

The problem with fad diets

The biggest issue with fad diets is that they can encourage the idea of a diet as a short-term behaviour, instead of a sustainable lifelong change. But there is no magic bullet when it comes to nutrition and health.

And when fad diets demonise particular foods or food groups, this can create an unhealthy relationship with food. This may lead to disordered eating and eating disorders.

Many fad diets do lead to initial weight loss, but these diets cannot be followed long term as most find the food rules too restrictive. This creates a vicious ‘yo-yo’ dieting cycle of weight loss followed by almost inevitable weight regain.

Because they often cut out nutritious foods, fad diets may cause the following problems:

  • Inadequate vitamin and mineral intake
  • Dehydration
  • Weakness and fatigue
  • Nausea and headaches
  • Constipation.

Fad diets that cut out food groups or nutrients may also mean that you miss out on the protective health effects of a balanced eating plan.

There is also a concern when a person turns to a fad diet who has real health problems like diabetes, heart disease or cancer or is in a vulnerable stage of growth and development and may not be giving themselves the best nutrition possible. Likewise, for an athlete, a fad diet may not be fuelling their performance as well compared to a diet that addresses all of their nutrition core needs which are often different to the general population.

Forget fad diets

When it comes to losing weight, there is no ‘one-size-fits-all’ dietary approach. The key is an eating pattern that is sustainable over time with a focus on eating well for good health.

So instead, take a longer-term view of your health based on advice from the Australian Dietary Guidelines.

And seek expert advice and support from an Accredited Practising Dietitian (APD).

Instead of following the latest fad diet, focus instead on nutritious food and being active. This will give you more energy and leave you feeling healthier.

When to see a dietitian
APD Logo

Diets for good health or weight loss should be well planned. An Accredited Practising Dietitian (APD) can help you meet your individual needs.

We recommend seeing a dietitian if you:

  • need nutritional advice to help ensure you're meeting your individual nutrient requirements
  • would like a personalised eating plan to help improve your eating habits
  • feel you have a poor psychological relationship with food and your body and struggle with making positive food choices
  • want to get off the fad diet roundabout
  • have specific nutritional needs, such as during pregnancy or for children.

Accredited Practising Dietitians (APDs) are university-trained nutrition experts. They can help you with personalised, easy-to-follow and evidence-based advice.

APDs are Australia's most trusted dietetics professionals.

Find a dietitian

Top tips
  • If the claims of a fad diet seem too good to be true, then they probably are.
  • The costs of following a fad diet include nutrient deficiencies, fatigue, weight regain and a poor relationship with food that can lead to disordered eating.
  • The better alternative to fad diets is to make small, achievable, lifelong changes to your lifestyle and eating habits.
This health advice page was peer-reviewed by an Accredited Practising Dietitian (APD) in January 2023.