What are the health risks of fad diets and what diet should you be following? Part 2

Now that we have the knowledge on how to see the red flags of a fad diet in disguise it is time to deep dive into the health risks of fad diets and why you should ditch them for good.

Fad diets on the surface seem relatively easy when you finally get the willpower and self-control in check. Fad diets take the guesswork out of what to eat and what not to eat with a strict set of rules and restrictions to follow. Let’s face it, there is so much conflicting nutrition information around so it seems like a match made in heaven. The problem with fad diets is that they’re not based on sound nutrition principles and lack scientific evidence as to their long-term success i.e. keeping the weight off for the rest of your life when you stop the diet. The risks of fad diets are many and here are a few of the most common:

Nutrient deficiencies

Many fad diets restrict entire food groups or macronutrients, which can lead to nutrient deficiencies. For example, a low-carbohydrate diet may be low in fibre and prebiotics which is important for digestive health including the gut microbiome, while a juice cleanse will be low in protein, which is important for muscle and tissue repair and immunity. Low carb diets can accelerate the loss of muscle mass, and compromise energy levels that can impair performance with exercise or sport, resulting in poorer recovery and increasing the risk of injury.

Yoyo dieting

Fad diets are often not sustainable in the long term, which means that people may lose weight initially but then gain it back (and sometimes more in 66% of cases) when they go off the diet. In addition to weight gain, this cycle of weight loss and gain can also lead to other health problems.

Increased risk of disordered eating and eating disorders

Fad diets can promote a very restrictive and unhealthy relationship with food and body. It encourages ‘all-or-nothing’ thinking where food is viewed as ‘good’ or ‘bad’ and can lead to guilt, shame, and anxiety around eating. This can contribute to eating disorders, the risk of which is higher if there is a family history of eating disorders. For parents, it also role models disordered eating patterns and body dissatisfaction to children e.g. counting calories, weighing food, and body checking. Fad diets can also increase preoccupation with food, eating and body with episodes of cycling between ‘sticking’ to the diet on weekdays and then ‘breaking’ the diet or bingeing on weekends or holidays.

Increased risk of chronic diseases

Fad diets that are very high in animal products or saturated fat may increase the risk of chronic diseases such as heart disease, diabetes, and cancer. Additionally, the stress of constant dieting can contribute to inflammation and other health problems such as kidney stones and  metabolic dysfunction-associated fatty liver disease (MAFLD)

Medical instability and other health issues

Sticking to a calorie-restricted fad diet in the long-term can result  in issues such as feeling cold all the time, headaches, dizziness, fainting, constipation, hair loss, dry skin, loss of energy and strength and dehydration.

Mental health issues

Fad diets can also have a negative impact on mental health. The stress of constantly thinking about food and weight or fat loss can contribute to anxiety and depression, while the guilt and shame associated with ‘failing’ on a diet can be very damaging to mood, self-esteem, and body image. A semi-starved state from prolonged strict dieting can also cause social withdrawal and isolation, strained relationships, and loss of sense of humour and enjoyment of life.

Disconnection to food and body signals

Fad diets are generally a one-size-fits-all approach that disconnects people from their internal body signals of hunger and fullness. It also impacts socialising with friends and family and culturally disconnects you from food if core staples are restricted or cut out e.g. pasta for Italians or rice for Indians and Asians

Side effects from medications

Prolonged fasting may interfere with medication dosage times and result in dangerous side effects. Some medications must be taken with food to reduce side effects such as nausea, reflux, or low blood glucose e.g. metformin taken for diabetes or PCOS.

Low libido and fertility issues

Highly restrictive diets with or without high-intensity workouts can lower libido as well as sex hormone levels such as oestrogen in women and testosterone in men and also affect egg and sperm quality.

Increased danger to self and others

Many fad diets restrict carbohydrates, which are an important source of energy for every cell of your body including your brain. Inadequate carb intake can lead to fatigue, low energy, brain fog, and difficulty focusing and concentrating. This can result in accidents in motor vehicles and using machinery and other equipment. It also can result in dangerous low blood glucose levels and also increase intoxication from alcohol.

As we have discovered, fad diets are also often not sustainable in the long term. Because they’re so restrictive, it can be difficult to stick to them for more than a few weeks or months. This means that most people who go on fad diets eventually gain back the weight they lost, and sometimes even more.

So what should you look for in a healthy eating plan? Here are some key principles to keep in mind:

Eating with balance and consistency

A healthy eating plan should include a balanced mix of carbohydrates, proteins, and fats across the day starting from breakfast. This will provide you with the energy and nutrients you need to thrive.

Focus on adding instead of taking away

Include a variety of foods from all food groups, including fun foods such as icecream and pizza.

Respect your food preferences and cultural heritage

A healthy eating plan aligns with your values around family and social connection and includes eating enough of the foods you enjoy.


A healthy eating plan should be sustainable in the long term which is easy when you give yourself permission to eat all foods and ditch fad dieting.

In summary, fad diets are dangerous and can be difficult to follow in the long term. They are often based on restrictive and unsustainable rules that can lead to nutrient deficiencies, yoyo dieting, disordered eating, increased risk of chronic diseases, and mental health issues. Instead, it’s important to focus on a balanced and sustainable eating plan that meets your individual health needs including family history of health conditions, current health status, stage of life, budget and values. Working with a qualified dietitian can help you develop an eating plan that’s right for your unique needs and that will support your overall health and wellness.

Reach out today to our Dietwise Care Coordinators today to get started by contacting us on – 08 9388 2423 Call button or You can even contact us through our website here. We are open 6 days per week for in-person and Telehealth appointments including both after-hours and Saturdays. As Credentialed Eating Disorder Clinicians we have specialised training and skills in weight concerns, disordered eating and eating disorders if you are concerned that fad dieting has impacted your relationship with food, weight and body.

Sonya Douglas

Accredited Practising Dietitian & Accredited Nutritionist

We're so glad you found us

Get In Touch

Reach out and tell us how we can help. We would love to hear from you.

Level 2, 448 Fitzgerald St, North Perth WA 6006