Diets and trends

Milk glass with tape measure image

There are hundreds of diets out there that are keenly followed by Australians of all ages.

It is important to think carefully about diets that cut out whole food groups. A balanced diet means eating a wide variety of foods from across the five food groups, in the amounts recommended, depending on a person’s age and gender. The five food groups recommended in the Australian Dietary Guidelines are:

Vegetables and legumes/beans


Grain (cereal) foods (mostly wholegrain and/or high cereal fibre varieties)

Lean meats and poultry, fish, eggs, tofu, nuts and seeds, and legumes/beans

Milk, yoghurt, cheese and/or alternatives (mostly reduced-fat).


Benefits and risks of diets

Diets and eating trends come with varying degrees of risks and benefits. Some recent diets include the following:

• The 5:2 Diet

• The Paleo Diet

• I Quit Sugar – Sarah Wilson

• The Mediterranean Diet

• The Total Wellbeing Diet.


Below is a brief description and analysis on each of these diets, and a summary of their benefits and risks.

Please note: As with all diets, people should seek medical advice before embarking on a restricted eating program.

  • The 5:2 Diet

    The 5:2 diet is based on a principle known as intermittent fasting where five non-consecutive days of the week are made up of regular, non-calorie counted eating, and the remaining two non-consecutive week days (fast days) are restricted to an intake of only 500–600 calories. The theory behind this diet is that periodic fasting can be good for weight loss, improved blood glucose control and lead to a reduced risk of heart disease, stroke and cancer. Evidence of the effectiveness of the 5:2 diet is, however, limited.

    If this diet is followed, individuals should ensure that non-fast days are packed with nutritious options like fruit, vegetables, wholegrains, lean protein (such as chicken, fish and turkey) and dairy foods like milk, cheese and yoghurt.


    • • Sticking to a regimen for two days a week is more achievable than seven days.

    • • No foods are banned and two days a week on a restricted diet could help individuals become more aware of flavour, healthy choices and their appetite.


    • • Diets restricted to 500–600 calories per day mean that only a small volume of food can be eaten. A diet on such few calories can cause dizziness, irritability, headaches and make it difficult to concentrate. Other reported side effects are sleeping difficulties, daytime sleepiness, bad breath and dehydration.

    • • Adherence can be difficult – the hunger experienced is a limiting factor for some.

    This diet can be unsafe for certain population groups such as teenagers and children who are likely to miss out on crucial nutrients needed for growth and development.

  • The Paleo Diet

    The Paleo Diet, also known as the Stone Age Diet, Caveman Diet or Ancient Diet, is an attempt to replicate the diet of humans of the Paleolithic age. The diet is high in fat and protein and low in carbohydrates. The Paleo Diet consists of foods that can be hunted or fished – such as meat and seafood – and foods that can be gathered – such as eggs, nuts, seeds, wild fruits and vegetables, herbs and spices. Foods that are the products of agriculture such as wheat, dairy, legumes, refined sugar, potatoes and salt are not part of the diet.

    Long-term, well designed studies are required to determine whether or not the Paleo Diet is effective in reducing the risk of ‘modern diseases’ such as diabetes, heart disease and cancer which is the theory.


    • • The Paleo Diet encourages less consumption of processed food and more nutrient-rich foods such as fruit and vegetables.

    • • Reducing consumption of high-kilojoule foods will reduce overall kilojoule intake to help manage weight, and ultimately improve other aspects of health and wellbeing.


    • • The Paleo Diet and associated health claims are not supported by scientific evidence.

    • • The Paleo Diet excludes whole food groups such as dairy foods and grains, which form part of a healthy, balanced diet. People following this diet should seek advice from an Accredited Practising Dietitian to ensure nutritional adequacy.  

  • I Quit Sugar

    The I Quit Sugar (IQS) diet, driven by Sarah Wilson in Australia, cuts out sugar over an eight-week program. Sugar is made up of 50% glucose and 50% fructose. It’s the fructose that is removed as part of the IQS diet plan. This diet removes foods such as:

    • Dried fruit, fruit juice and fresh fruit high in fructose

    • Jams (even if no added sugar)

    • Condiments containing sugar (e.g. tomato and barbecue sauces, balsamic vinegar)

    • Flavoured yoghurts

    • Agave

    • Palm and coconut sugar

    • Chocolate, soft drink, confectionary etc.

      Sarah Wilson claims fructose encourages us to eat more, converts directly to fat and ‘makes us sick’. Other sugars (glucose, maltose and lactose) are safe to eat in moderation.

      The World Health Organisation recently updated its recommendations to reduce intake of free sugars to less than 10% of total energy with a further recommendation to reduce them to 5%, following reviews of the scientific evidence of the link with obesity and dental caries.1 Free sugars include monosaccharides and disaccharides added to foods and beverages by the manufacturer, cook or consumer and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates.


      • • Avoids processed foods and focuses on whole, nutrient rich foods.

      • • Promotes beneficial bacteria, fibre and enzymes to support optimal digestive functioning.


      • • Everything processed is eliminated including anything canned, dried, frozen and in a packet – from canned tomatoes to frozen peas to pre-made marinades and rubs. This is impractical and can be hard to achieve for those living in rural or remote areas far from fresh food providers.

      • • The program requires a lot of self-discipline and may not be sustainable in the long term. Sarah Wilson says that most people will experience a period of detox that can make people feel terrible. 

      • • Cutting out certain fruits limits choices and variety. Fruit is a five food group food which makes a satisfying dessert and easy snack and contributes to daily fibre intake for a healthy digestive system.

      1 World Health Organisation. Guideline: Sugars intake for adults and children. Geneva: World Health Organization; 2015. Available:

    • The Mediterranean Diet

      The Mediterranean Diet emphasises consumption of foods with healthy fats — those containing omega-3 fatty acids — plus other foods that support a heart-healthy diet. The diet includes consumption of fruits, vegetables, wholegrains, legumes, nuts, olive oil and herbs and spices. Eating fish and seafood several times a week is encouraged as well as poultry, eggs and fermented dairy foods (cheese and yoghurt) in moderation. This diet is well-researched and has been shown to be protective against diabetes,1heart disease,2cancer,3 dementia4and ensures longevity and a healthy weight.5


      • • The Mediterranean diet includes all five food groups.

      • • Diverse flavours keep the diet enjoyable.

      • • May be easier to adhere to than more limiting calorie controlled diets.

      • • Scientific evidence supports claimed health benefits.


      • • May be more expensive and time-consuming.

      • • Not designed as diet for weight loss.

      • • Can be tendencies for people to indulge/overeat as the diet is more flexible.

      While the diet includes some cheese and yoghurt, it does not include a lot of milk so people who follow it have to pay attention to their calcium intake.

      1 Hodge AM, English DR, Itsiopoulos C, O'Dea K, Giles G. Does a Mediterranean diet reduce the mortality risk associated with diabetes: evidence from the Melbourne Collaborative Cohort Study. Nutr Metab Cardiovasc Dis. 2011;21(9):733-9. doi: 10.1016/j.numecd.2010.10.014.

      2 Estruch R, Ros E, Salas-Salvadó J, Covas M, Corella D, Arós F et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368(14):1279-90

      3 Couto E, Boffetta P, Lagiou P, Ferrari P, Buckland G, Overvad K et al. Mediterranean dietary pattern and cancer risk in the EPIC cohort. Br J Cancer. 2011;104(9):1493-99.

      4 Lourida I et al. (2013). Mediterranean diet, cognitive function, and dementia: a systematic review. Epidemiology. 24(4):479-89. doi: 10.1097/EDE.0b013e3182944410.

      5 Sofi F, Abbate R, Gensini G, Casini A. Accruing evidence on benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis. Am J Clin Nutr. 2010;92(5):1189-96.

    • The Total Wellbeing Diet

      The CSIRO Total Wellbeing Diet is a high protein, low-fat diet developed and tested by the CSIRO. Based on years of research, it has been scientifically validated as a nutritious diet for sustainable weight and fat loss. The high-protein diet also can lower glucose and insulin levels and helps to control hunger. Kidney function and bone turnover markers are not affected – a major criticism of other high protein diets such as Atkins-style diets. The diet includes a healthy eating plan combined with exercise and is an effective way to improve overall health and wellbeing.


      • • The CSIRO Total Wellbeing Diet recipes include a variety of ingredients from all the food groups to ensure nutritional balance. Each individual’s daily food groups’ target is based on their personal needs including age, gender, nutrient and kilojoule requirements.

      • • The diet can result in safe weight loss by reducing overall kilojoule intake.


      • • Questions have been raised about the high meat intake as part of the diet and whether this could increase the risk of bowel cancer. The strongest link between meat and cancer appears to be with processed deli meats,1 however if there is a family history of cancer, individuals may want to consider decreasing the recommended meat serves as part of the diet.

      1 Bouvard V, Loomis D, Guyton K, Grosse Y, Ghissassi F, Benbrahim-Tallaa L et al. Carcinogenicity of consumption of red and processed meat. Lancet Oncol. 2015;16(16):1599-1600.