DAA’s ‘hot topics’ summarise the latest research and current thinking on topical nutrition issues in the media.
The gut microbiome (November 2017)
Digestive health is currently one of the hottest topics in nutrition. But why this sudden interest in a healthy gut? What is the gut microbiome and how is it linked with health?
Digestive health is currently one of the hottest topics in nutrition. But why this sudden interest in a healthy gut?
The role of the gut microbiome (also called ‘microbiota’) in health and disease is an area of intensive research – and is making media headlines, with many people keen to learn how to tap into the benefits, including through the foods they eat. But the gut microbiome is a rapidly developing and young field, and there are many aspects of the microbiome that are not yet well understood.
What is the gut microbiome?
The term ‘gut microbiome’ refers to the collection of microorganisms (including bacteria, arachea, viruses, fungi and unicellular eukaryotes) that live in our gastrointestinal tract (or gut), with the greatest number and diversity in the colon.
Emerging evidence suggests that while environmental factors such as diet, medications (like antibiotics) and disease conditions can affect the make-up of our gut microbiome in a short time frame (as little as a few days), our genes most certainly also have a role to play.
How is the microbiome linked to health?
Long gone are the days when we assumed that all bacteria were harmful! While there is still more to learn about the gut microbiome, the best evidence to date is around its role in areas such as digestion, metabolism and immunity.
The early years
Colonisation of the gut begins at birth – and the passage of infants through the birth canal seems to be really important. As well as this, exclusive breastfeeding encourages growth of beneficial microbiota. Research tells us that babies delivered by caesarean section and those not exclusively breastfed have a microbiome that is initially less diverse.
Digestion, metabolism and immunity
The gut microbiome is key in a number of metabolic functions in our body, including synthesising a variety of vitamins (all B vitamins and vitamin K) and amino acids, digesting carbohydrates (such as insoluble fibre, resistant starch, pectins, gums and cellulose), producing short-chain fatty acids, and assisting bile with glucose and cholesterol metabolism.
In addition, many chemical mediators produced by the gut microbiome enter our blood stream and communicate with organs such as our brain, heart and liver.
Gut microbiota are also our first internal line of defence against pathogens (or harmful bacteria), protecting the body against disease, alongside our immune system. They produce antimicrobial compounds and compete for nutrients and sites of attachment in the lining of our gut, and in doing so suppress (or prevent colonisation) of pathogens2.
Researchers are discovering that a disruption in the gut microbiome may been linked with certain diseases, but the specific contribution of the microbiome to these conditions is not yet clear.
Dysbiosis of the gut microbiota (that is, an imbalance among the microorganisms in the body) is thought to affect metabolism and play a role in certain conditions, such as obesity, non-alcoholic fatty liver disease, neurodevelopmental disorders (such as autism), anxiety and depression, and gut-related conditions (such as irritable bowel syndrome and inflammatory bowel disease).
Researchers are unsure how manipulating the microbiota (such as by changing the specific species of microorganisms in the gut or altering the balance of these) might be able to be used to prevent or treat these conditions. So, we still have some way to go in understanding exactly how best to harness the microbiota.
What impact does diet have on the gut microbiome?
Diet has a huge influence on our gut microbiota composition. Some researchers suggest today’s typically low-fibre, Western-style diet as a reason for a loss of diversity in the gut microbiome.
And our gut microbial profile will be different if we eat, for example, a diet based on plant foods or one rich in animal foods – due to corresponding changes in the bacteria involved in metabolising the nutrients in these foods (whether that be carbohydrates or protein).
Unfortunately, many Australians don’t eat enough dietary fibre – which directly affects gut health. On average, Australians are not getting the recommended daily amounts of at least 25g of fibre for women and 30g for men. Eating enough dietary fibre (both insoluble and soluble fibre) has many health benefits, including improving gut health.
Probiotics and prebiotics
Sometimes called the ‘dynamic duo’, prebiotics and probiotics affect the gut microbiome, and interest in these continues to increase. But there are many knowledge gaps around probiotics and prebiotics, and their effect on gut microbiota.
Probiotics are ‘good’ bacteria or yeasts (like those found naturally in the gut) that, when taken in adequate amounts, can improve the balance of the gut microbiome. A lot of research has been done on probiotics and the evidence on their efficacy is mixed, with most health-related effects thought to be strain specific. Probiotics are found in everyday foods like yoghurt, milk drinks like kefir, and other fermented foods, like kombucha, kimchi, miso, tempeh, sauerkraut and sourdough bread. Probiotic supplements are also available.
In contrast, prebiotics are types of carbohydrates that reach the large bowel unchanged (that is, they are not digested or are only partly digested) and can, as a result, encourage beneficial microbes or ‘good’ bacteria to grow in the gut. Examples of prebiotic foods include cereal grains, vegetables (including asparagus, onions and cabbage), legumes (like chick peas and lentils), fruit (such as bananas and nectarines) and nuts. More research is needed on the links between prebiotics and any direct health benefits.
Resistant starch is another component of food which has been linked with gut health. Resistant starch isn’t fully broken down in the small intestine, so reaches the colon intact – where it stimulates gut microbiota to produce short-chain fatty acids. One of these, butyrate, helps keep the lining of the colon healthy. Examples of foods containing resistant starch are firm bananas, lentils, peas, potatoes that have been cooked and cooled, cold pasta, and certain wholegrain products.
The bottom line:
The gut microbiome is complex and largely poorly understood. With research in this area booming, in the future we will better understand the connection between the microbiome and diseases.
So how do we reach a healthy gut microbiome, based on our knowledge so far? Aim for a healthy, balanced and varied diet, based around whole foods, and rich in fibre. Resistant starch is also important for gut health, and consider probiotic and prebiotic foods, which are considered safe to eat.
For people who are confused about what the eat or want more specific advice, DAA recommends seeking this from an Accredited Practising Dietitian (APD). Your APD will be able to translate the latest evidence on gut health, into practical, everyday advice and also has the skills to support you on your journey towards better health.
 Practice-based Evidence in Nutrition. Knowledge Pathway: Gastrointestinal system – Microbiota background.
 Sidhu M, van der Poorten, D. The gut microbiome. Aust Family Phys, 2017; 46(4): 206-11.
 Bull MJ, Plummer NT. Part 1: The human gut microbiome in health and disease. Integr Med (Encinitas), 2014; 13(6):17-22.
 Graf D, et al. Contribution of diet to the composition of the human gut microbiota. Microb Ecol Health Dis. 2015; 26:261-64.
 Australian Bureau of Statistics. Australian Health Survey: Nutrition First Results – Foods and Nutrients, 2011-12.
Low carb, high fat diets for diabetes (November 2017)
What’s a low carb, high fat diet? And is there a role for this eating pattern in managing diabetes? In this Hot Topic, we summarise the evidence behind low carb, high fat diets for people with diabetes.
Low carbohydrate, high fat diets for diabetes mellitus?
Low carbohydrate, high fat diets have recently re-emerged (having last been popular in the 1970s), and have caught the attention of some members of the scientific community and the public.
Dietitians want to make the management of diabetes mellitus easier and strive to provide the best possible advice to the public as the nutrition science continues to evolve. So what about ‘Low Carb, High Fat’? Is it really the best if you have diabetes? And, is it sustainable?
What are the goals of diabetes care?
When you have diabetes mellitus, the aim is to manage your blood glucose levels, your blood fats and your blood pressure as best as possible. Advice about food and eating is very important because in both the short term (3-6 months), and the long term (2 or more years), it influences your health and how you feel.
Advice should always be supported by the best-quality science and be individualised for each person to match their health goals, comorbidities, nutrition status, personal and cultural preferences, access to healthy choices, and readiness and willingness to change (1). To this end, there is no single optimal diet for all people who have diabetes – there are many different ways of eating well (2).
Nutritional management of diabetes should be reviewed and, if needed, altered over time, based on assessment from an Accredited Practising Dietitian (APD).
What is a low carbohydrate diet?
Well, that’s part of the problem . . . ‘low carbohydrate’ is poorly defined.
In research, some have used ‘Very Low Carbohydrate Ketogenic Diets’ (VLCKD) with amounts from 20-50g carbohydrate per day (less than four ‘portions’). These diets often omit whole food groups and make it very difficult to meet all known nutrient and fibre targets, and therefore could not be recommended for diabetes management in the long term (2).
Others have suggested that ‘Low’ is <130g/day (26% of energy based on a person’s intake of 8,400kJ/day). ‘Moderate’ carbohydrate falls between 130-230g/day (26-45% of energy based on a person’s intake of 8,400kJ/day) and then ‘High’ carbohydrate is >230g/day (45% of energy based on a person’s intake of 8,400kJ/day) (3).
Is there a role for low carbohydrate diets?
In the short to medium term, low carbohydrate diets with optimal saturated:unsaturated fat ratios appear to be a safe and effective option for weight loss, improvement in glycaemic control and cardiovascular risk for adults with type 2 diabetes (3,4,5,6). However, when compared with other dietary approaches, at varying levels of carbohydrate intake over longer time periods, low carbohydrate diets do not appear to be superior (5,6,7,8,9,10).
A recent systematic review and meta-analysis of a variety of diets (Low Carbohydrate, Low Glycaemic Index (GI), Mediterranean and High Protein) for people with diabetes, found some benefits for a low carbohydrate diet in the short term (8). Including:
- Some improvement in HbA1c (although the Low GI diet and the Mediterranean diet performed better on this measure)
- Weight loss (although those in the Mediterranean diet group lost more weight)
- Improved HDL cholesterol (also seen in the Low GI and Mediterranean diet groups).
When it comes to weight loss, Naude et al (11) examined nineteen trials (n=3,209) and were also able to confirm that weight loss occurs in the short-term, irrespective of the proportion of macronutrients. They found no difference between low carbohydrate or ‘balanced diets’ in regards to weight loss (or cardiovascular risk factors) even when participants are followed up for up to two years. There was also no difference in weight loss or cardiovascular disease risk factors in participants who were overweight or obese or in those with or without type 2 diabetes.
One of the main problems is that it can be difficult to translate this low carbohydrate diet into foods, without dramatic changes to the types of foods normally eaten. This can create challenges for people who live with others (such as in a family setting) to adjust the diet to suit everyone in the household and it may risk some members nutritional needs, particularly children and adolescents.
Also, some people may incorrectly believe that this type of diet means they can simply eat more meat. This is not true. For health reasons, the Australian Dietary Guidelines place a limit on meat consumption at ~455g/week for adults.
People with diabetes may also be misled by the idea of replacing some carbohydrates with foods high in saturated fat – however, research shows this can actually increase insulin resistance (2). Research showing improvements to lipids (blood fat) levels with a low carbohydrate diet (4,7) have ensured carbohydrates were replaced with appropriate types of fat (unsaturated) – resulting in an optimal saturated:unsaturated fat ratio – to prevent adverse lipid profiles.
What about those on medication for diabetes?
For people using certain glucose lowering medications or insulin, there is a high risk of hypoglycaemia when following a low carbohydrate diet (3,5). So diabetes (hypoglycaemic) medications may need adjusting, under medical supervision, if a person chooses to adopt a low carbohydrate diet.
Important information about carbohydrate foods
The amount, type and frequency of carbohydrate foods in a diet pattern is an important consideration in the management of diabetes mellitus. Foods that are considered carbohydrate choices are many and varied, and are of differing quality.
Low glycaemic index (GI) food choices (GI<55) are important in selecting the right carbohydrate foods for you. And overall, the reduction in total energy (kilojoule) intake is key to glycaemic control in most people with type 2 diabetes. Dietitians also recommend people with diabetes spread their carbohydrate food choices over the day, to assist with glycaemic control.
Diabetes Australia (12) recommends eating regular meals and spreading carbohydrate foods evenly throughout the day, to help maintain energy levels without causing large rises in blood glucose levels. The organisation also recommends people with diabetes eat moderate amounts of high-fibre, low GI carbohydrates. Diabetes Australia also point out that carbohydrate needs differ from person to person, so they suggest seeking individualised advice from an APD.
Are carbohydrate foods needed by the body?
While there are specific requirements for amino acids (from proteins) in the diet, and essential fatty acids (from fats), there is talk that there is no specific requirement for carbohydrate.
This is not true. Both your brain and red blood cells require glucose and while some can be supplied by breaking down proteins in your body, there are a number of reasons why this is not beneficial and is specifically not recommended – for example, during childhood (due to growth requirements) and during pregnancy. The long-term effect of placing this demand on the body has also not been tested and there is evidence to suggest that performance in mental and physical tasks could be affected. Therefore, a diet that is very low in carbohydrate may not be physically or mentally sustainable as a diet pattern.
In addition, carbohydrate foods supply many nutrients. These include B vitamins and fibre from grains, and vitamins, minerals, dietary fibre and other plant components such as antioxidants from fruit and starchy vegetables. So without careful planning, it can be more difficult to meet nutrition needs on a low carbohydrate diet.
Consistent evidence indicates that in general, dietary patterns higher in plant-based foods such as vegetables, fruits, wholegrains, legumes, nuts and seeds, and lower in animal-based foods are more beneficial for overall health. This type of diet also has a lower impact on the environment and is therefore more environmentally sustainable as a recommendation for the population.
What are Australians eating?
From the latest National Nutrition Survey (13), data suggests, on average, Australians are consuming about 222g of carbohydrate per person per day, making up 43.5% of total energy intake. This indicates a ‘moderate’ carbohydrate intake across the population. Furthermore, for Australians, this amount has decreased since the last National Nutrition Survey in 1995.
To put this into perspective, the Australian Dietary Guidelines, which have been designed for healthy populations, suggest from 45-65% of total energy intake come from carbohydrate foods (Note: this is purposefully a wide range, to account for factors such as a person’s level of physical activity and personal food preferences).
What if I don’t have diabetes? Is a low carb diet right for me?
The truth is, there are many ways to have a healthy diet – there is no ‘blanket’ one-size-fits-all approach for everyone, as we’re all different.
The Dietitians Association of Australia (DAA) recommends seeking advice from an APD before dramatically altering your diet or that of your family – especially if you are considering cutting out whole food groups. An APD will assess your diet and work with you to personalise an eating plan that’s right for you, taking into account factors such as your health goals, and your personal and cultural preferences.
A word on saturated fats
In ‘Low Carb, High Fat’ diets, a variety of fats have also been suggested as replacements for carbohydrate foods. All fats are rich in energy (kilojoules) – containing twice the amount of kilojoules as either protein or carbohydrate, so if eaten in large amounts, can make weight control more difficult.
Some LCHF diets promote foods like coconut oil and animal fats, often suggesting these are more ‘natural’ sources of fat, but these foods are higher in saturated fat. And according to the Heart Foundation (14), eating a lot of saturated fat increases blood cholesterol, and in particular the bad (LDL) cholesterol.
The Australian Dietary Guidelines also recommend Australians limit intake of foods high in saturated fat, such as:
- Many biscuits, cakes, pastries, pies, processed meats, commercial burgers, pizza, fried foods, potato chips, crisps and other savoury snacks.
- Butter, cream, cooking margarine, coconut and palm oil.
The bottom line
DAA acknowledges that there is no ‘one best diet’ for managing type 2 diabetes.
Instead, there are a range of beneficial nutrition interventions and dietary patterns for people with type 2 diabetes, which may be recommended by an APD after assessing an individual’s diet. APDs are trained to take into account factors such as a person’s nutrition needs, background and preferences – and to then tailor Medical Nutrition Therapy to an individual.
There are a range of carbohydrate intakes that can assist with diabetes management.
A low carbohydrate, high healthy fat diet may be used by some nutrition professionals in the short term to achieve particular health goals. This approach won’t be for everyone, but for some people, it might be worth trying, with support from an APD to ensure nutritional adequacy, to help identify healthier protein and fat sources, and to assist with long-term adherence.
It’s important to remember that:
- The efficacy and safety of low carbohydrate diets for people with type 2 diabetes has not been examined in the longer term. That is, there are no clinical trials of two years or more examining the health effects of this eating pattern.
- Clarity is needed regarding the definition or description of low carbohydrate, high fat diets that have, in some studies, been associated with weight loss or improved metabolic profile.
What we do know from the evidence is that eating a wide variety of nutritious foods, in the right amounts, is crucial to optimal health. And the best diet or eating pattern is one you can maintain over the long term. Lastly, DAA recommends people with diabetes seek advice and ongoing support and monitoring from a health professional.
- Evert et al (2014) Nutrition Therapy Recommendations for the Management of Adults With Diabetes. Diabetes Care, 37(Suppl 1): S120-43.
- Dworatzek et al (2013) CanadianDiabetes Association Clinical Practice Guidelines Expert Committee, Canadian Journal Of Diabetes, 37(S Suppl 1): S45-55.
- Feinman et al (2015) Dietary carbohydrate restriction as the first approach in diabetes management. Critical Review and Evidence Base Nutr, 31: 1–
- Tay J et al (2015) Comparison of low and high carbohydrate diets for type 2 diabetes management: A randomised trial. Am J Clin Nutr, 102(4): 780-90.
- Dyson P. (2015) Low carbohydrate diets and type 2 diabetes: What is the latest evidence? Diabetes Therapy, 6(4): 411-24.
- Wylie-Rosett et al (2013). Health effects of low-carbohydrate diets: Where should new research go? Curr Ciab Rep, 13(2): 271-8.
- Van Wyk et al (2016). A critical review of low carbohydrate diets in people with type 2 diabetes. Diabetes Med, 33: 148-57.
- Ajala et al (2013) Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. Am J Clin Nutr, 97(3): 505-16.
- Emadian et al (2015). The effect of macronutrients on glycaemic control: a systematic review of dietary randomised controlled trials in overweight and obese adults with type 2 diabetes in which there was no difference in weight loss between treatment groups. Br J Nutr, 114(10): 1656-66.
- Yokoyama et al (2014). Vegetarian diets and glycaemic control in diabetes: A systematic review and meta-analysis. Cardiovasc Diagn Ther, 4(5): 373-82.
- Naude et al (2014) Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis. PLoS ONE 9(7): e100652. doi:10.1371/journal.pone.0100652.
- Diabetes Australia: https://www.diabetesaustralia.com.au/what-should-i-eat Accessed November 2017
- Australian Bureau of Statistics, 2011-12. Australian Health Survey: Nutrition First Results – Foods and Nutrients, 2011-12 http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/4364.0.55.007main+features12011-12 Accessed November 2017.
- Heart Foundation: https://www.heartfoundation.org.au/healthy-eating/food-and-nutrition/fats-and-cholesterol/saturated-and-trans-fat Accessed November 2017.
Fad diets (August 2017)
Fad diets can be tempting as they offer a quick fix to a long-term problem. But sadly, there is no magic bullet when it comes to nutrition and health. But what exactly is a fad diet, why do they tempt so many Australians, and do they work in the long-term? We answer these questions and more in our latest hot topic.
A fad diet is one that promises fast weight loss or radically-improved health, without a scientific basis and is often contradictory to current health advice. Fad diets often cut out entire foods or food groups, are based on a ‘one-size-fits-all’ approach, focus on short-term changes, make claims based on testimonials or a single study, and can involve miracle pills, shakes, or supplements.
What most fad diets have in common is that that encourage you to cut down on the amount of energy, or kilojoules, that you take in. But due to their very nature, ‘quick-fix diets’ aren’t sustainable and once stopped, most people find themselves back where they started. Any diet that excludes key food groups, or is overly restrictive, will raise the risk of nutrient deficiencies, without careful planning to overcome this.
When it comes to health, it makes better sense to take a long-term approach to what you eat. We know any diet that restricts overall energy will likely lead to weight loss in the short-term, but it’s the eating pattern that you enjoy, can stick to, and that fits with your lifestyle that will see long-lasting results.
Instead of resorting to drastic changes in your diet, that have no long-term evidence in regard to safety or efficacy, consider small tweaks you can make that will make the world of difference to how you feel today and your overall health and wellbeing over time.
Vegetables, for example, are jam-packed with vitamins, minerals, and antioxidants, and are low in energy, yet less than seven per cent of Australian adults meet the recommended five-a-day target. And on average, more than one third (35 per cent) of our total energy intake comes from ‘discretionary’ or extra foods like alcohol, soft drinks, cakes, confectionary and sweet or savoury biscuits.i So making small changes, such as eating more vegetables and less discretionary foods, will give you the best results.
Some fad diets have been making headlines this year…
• The cabbage soup diet: Promotes a week of eating cabbage soup, along with certain foods on set days (for example, bananas and skim milk on day four, beef and tomatoes on day five). While the soup makes a warming and tasty meal that will boost the vegetables in your diet, alone it is unlikely to cover all of your nutritional needs, and the confusing food rules the diet pushes are not based on any reliable evidence. By significantly cutting down on the overall energy you take in, the cabbage soup diet will most likely lead to weight loss. But any weight lost is likely to be a combination of muscle glycogen stores, water, and possibly muscle mass. So without making any other changes, once you resume normal eating, this weight will be regained.
• The GM diet: Originally making headlines in the 1980s, this diet has resurfaced recently, receiving media attention for its rule-based one-week eating program. Each day consists of a different combination of fruit, vegetables, milk, tomatoes, and meat, and while it will likely lead to some initial weight loss, after the week is through this will likely be regained. What’s more, it is very restrictive, making it difficult to follow – including when trying to work in with family meals or social occasions.
Fad diets: The potential risks
The safety of fad diets over the long-term is unknown. Because they can be highly restrictive, and often cut out key food groups, following a fad diet means you’re at risk of missing out on important, protective nutrients, that are needed for good health.
For that reason, they are especially unsuitable for certain people. Children and teenagers, athletes and highly-active people, those with diabetes, pregnant women, and people with a history of eating disorders should all steer clear of fad diets.
And severely cutting down on food may lead to a range of unpleasant side effects, like fatigue, feeling foggy-headed, affected mood, feeling ‘hangry,’ constipation, and headaches.
Accredited Practising Dietitians: All about tailored, evidence-based advice
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. DAA encourages Australians to take a longer-term view to weight loss, based on the recommendations of the Australian Dietary Guidelines, and to seek expert advice and support from an Accredited Practising Dietitian (APD). APDs tailor their advice to suit each individual’s lifestyle, goals, health status, and preferences. Their practical advice has a solid grounding of scientific evidence, so you can be confident that you’re making a long-term investment in your health.
Ketogenic diet (August 2017)
There has been a renewed interest in low carbohydrate, high fat (LCHF) diets in recent years, and amongst the variations of these is the ketogenic diet (KD).
What is a ketogenic diet?
A KD eating pattern is very low in carbohydrates and moderate in protein, meaning a high percentage of total energy (kilojoule) intake comes from fat.
As fat is the main source of energy being consumed, the body must then use this (that is, break it down) as its main energy source or ‘fuel’. When dietary fat is metabolised for energy, by-products called ‘ketone bodies’ (molecules that are made by the liver from fatty acids) are produced which are used up by the body’s tissues, muscles and the brain. This process is known as ‘ketosis’.
The body can enter ketosis during times of severe energy restriction (such as during fasting or starvation) or prolonged intense exercise, or when carbohydrate intake is reduced to around 50g per day, or less – the equivalent of around two slices of bread, and a banana.
Short-term side effects of ketosis can include fatigue, bad breath, nausea, constipation, and headache.
A ketogenic diet differs from other low carbohydrate, high fat diets
Many popular diets encourage short stints of a very low energy intake to bring on ketosis to ‘kick-start’ weight loss. When this is done by restricting carbohydrates, it can mean beginning with periods of eating as little as 20g of carbohydrates per day, and slowly increasing to more than 50g per day.
But the difference between a LCHF diet and a true KD is that the latter remains proportionately lower in carbohydrates – 20-50g per day, and less than 10 per cent of total energy, keeping the body in a state of ketosis, even if total energy intake increases.
Evidence for the ketogenic diet
Research supports a role for the KD as a medical intervention for some cases of epilepsy (that is, when seizures are intractable), particularly in children.[i] Epilepsy is a chronic neurological disorder characterised by recurring seizures, and though the exact mechanisms are unknown, a KD has been found to reduce frequency and severity of seizures.
KDs have been used to treat epilepsy in children since the 1920s, and are only recommended to be trialled with the full support of a multidisciplinary medical team, including dietitians, neurologists, nurses, pharmacists, and social workers. A dietitian’s support is vital, as a KD is very restrictive, with foods like starchy vegetables, dairy foods, fruit, and grain foods limited – making it difficult to meet long term nutrient needs for key vitamins and minerals, such as folate and calcium. As such, nutrient needs must be carefully monitored.[ii]
There is growing interest in the effect of a KD in patients with cancer, particularly brain cancer. Tumour cells have an increased reliance on glucose, and many cannot use ketones effectively, so the hypothesis is that disrupting cellular metabolism may improve current treatments. Additionally, some researchers propose that ketones may be toxic to some cancer cells.[iii] While the current research and preliminary results from clinical trials suggest a KD may show anti-cancer and neuroprotective effects, there are various limitations to consider. Much of the current evidence is observational, undertaken in small populations, and in animals, so further research is needed before strong conclusions can be drawn.[iv]
So although many books and websites propose a KD for a variety of health benefits, the evidence for these in healthy individuals is currently limited to therapeutic uses in specific conditions. In reality, the diet is backed by very limited evidence in healthy individuals.
The ketogenic diet for weight loss
Following a KD will undoubtedly result in short-term weight loss, which probably comes down to a reduction in total energy (kilojoule) intake, the depletion of liver and muscle glycogen stores and associated water, and a reduced appetite (which is a side-effect of metabolising ketones, and also due to satiety associated with eating foods containing fat and protein).[v]
But the key to maintaining a healthy weight in the long-term is an eating pattern that is sustainable over time. With this in mind, dietary recommendations should always be tailored to an individual – as everyone is unique, and what works for one person, may not work for another. That is, there is no one-size-fits-all approach when it comes to achieving and maintaining a heathy weight.
Limitations of the ketogenic diet
A strict KD is undoubtedly difficult to stick to because it drastically reduces the intake of a number of food groups, including fruit and vegetables, dairy foods, and grain foods. This means carbohydrate-containing foods, such as breads, cereals, rice, pasta, legumes, fruit, and starchy vegetables (like pumpkin, peas, and potato) must all be limited.
In fact, the 20-50g of carbohydrates allowed in a KD is equivalent (in carbohydrate terms) to just a small tub of yoghurt, an apple, and half a medium potato over a day. So, using fruit as an example, following a KD would likely mean limiting fruit to only one serve a day, or eating it in place of other nutritious foods like vegetables, dairy foods, and grains[vi]. This requirement to strictly limit certain foods makes it near impossible to meet nutrients needs without supplementation.
With limited carbohydrates, a KD is very low in fibre, so can cause gastrointestinal symptoms like constipation. It may also increase the risk of bowel cancer in the long-term. The KD can also present challenges relating to the social aspects of eating, such as enjoying food in family and social situations.
Studies involving KDs have high dropout rates, with a Cochrane review of the KD in epilepsy patients reporting attrition rates between 10-20 percent.[vii] This suggests that sticking to a KD diet is challenging – mostly due to its restrictive nature.
A note on the benefits of vegetables, fruit and wholegrains
Eating wholegrains is linked with a reduced risk of health conditions like type 2 diabetes, cardiovascular disease and bowel cancer, largely due to their fibre content and other protective components called phytonutrients.[viii] A major review of 304 meta-analyses and systematic reviews even found grain foods are more protective than fruit and vegetables against diet-related chronic diseases.[ix]
Fruit and vegetables are, however, an excellent source of vitamins, minerals, dietary fibre and phytochemicals, which are linked with a range of functions in the body, including gut health and immunity. Less than one in 10 Australians meet the recommended amount of vegetables a day, and only one in two reach the two-a-day fruit target, so for many Australians eating adequate amounts of fruit and vegetables is a sure-fire way towards better health.
The fibre in wholegrains, fruit, vegetables, and legumes supports the growth of ‘good’ bacteria, which keeps the lining of the bowel healthy. On average, we eat only half the recommended daily amounts of at least 25g of fibre for women and 30g for men – and being on a ketogenic diet will make it harder to meet these targets.
Take home message
Though it may offer some metabolic benefits when followed in the short-term (a few months), and pose as a novel treatment for certain medical conditions, a KD isn’t recommended for the general population, as the long term efficacy and safety of the diet are unknown, having only been studied in the short-term.
And as always, for people who are confused about what they eat or want more specific advice, DAA recommends seeking this from an Accredited Practising Dietitian (APD). And if you choose to undertake a KD, this should be done under clinical supervision – with the guidance of a health professional, such as an APD.
Health Star Ratings – What is it and how do I use it? (July 2017)
The Health Star Rating (HSR) is a voluntary labelling system for packaged foods designed to help you make healthier choices. Food packages can be labelled with a rating from a ½ star to five stars as an easy way to compare similar packaged foods at a glance, based on their overall nutritional profile.
The HSR system was developed by the Australian Government in partnership with industry and public health and consumer groups.
What does DAA think of the HSR?
On the whole, DAA is supportive of front-of-pack labelling. But we also know that a rating system like this is complex, and there is no perfect solution.
The HSR system has been designed to place stars on packaged foods only. This means whole foods such as fresh fruits and vegetables are unable to carry stars, and yet ‘discretionary foods’ such as confectionary can. This is confusing when you are trying to make healthy food choices.
The HSR message ‘the more stars the healthier the choice’ does not make it clear it is only for packaged foods. If you are trying make healthy choices this may leave you wondering if the packaged snack with the HSR label is a ‘healthier choice’ than the bag of fresh apples with no HSR label.
Help improve the HSR
Consultations on the HSR are happening at the moment, and DAA looks forward to contributing feedback. If you feel strongly about the HSR, we encourage you to have your say.
It is important that the Government continues to invest in strategies that support healthy eating for all Australians. This includes front of pack labelling strategies and funding of programs to help you make informed food choices that follow the Australian Dietary Guidelines. An Accredited Practising Dietitian can also help you with this.
The Health Star Rating (HSR) system has recently been the focus of some discussion in the media and on social media. DAA is aware that there are two consultations on the HSR currently underway – one on the ‘as prepared’ issue, and the other regarding the five-year review of the HSR. DAA is currently preparing submissions to both of these consultation processes. All DAA members are able to provide input either directly to the consultation processes or they can contribute to the DAA submissions.
On the whole, DAA is supportive of a front-of-pack labelling system however, we also acknowledge that these systems are complex and, as is the case with the HSR, anomalies can occur.
Intermittent fasting (June 2017)
Eat very little for a couple of days, then eat whatever you’d like for the rest of the week, and lose weight… Sounds easy, but if you’re seeking weight loss, does intermittent fasting stack up? Read more in our Hot Topic.
What is it?
The idea of reducing your kilojoule (energy) intake from food to lose weight is nothing new, and while fasting has been a part of many religions for centuries, doing so on some, but not all days of the week for health is a relatively new concept.
Popularised by diet programs like the ‘5:2 diet,’ a typical week of intermittent fasting might involve two (non-consecutive) days of eating around 25 per cent of your energy requirements, then eating normally on the remaining five days of the week. Other programs are more arduous, and suggest ‘fasting’ every second day.
Energy requirements are individual, based on factors like height, age, gender, and activity level. But in general, a fasting day involves eating and drinking around 2,000 – 3,000 kilojoules worth of food and drinks. To put this in context, two boiled eggs, a slice of wholemeal toast, and an apple amount to around 1,000 kilojoules, so it’s clear to see a fasting day wouldn’t involve much food.
What does the evidence say?
Supporters of intermittent fasting point to weight loss, and improvements in risk factors for chronic disease, like reduced cholesterol, as reasons to follow the diet. But while the current body of evidence tells us that while intermittent fasting diets may lead to weight loss, it’s unlikely they’re superior to a standard balanced reduced-kilojoule diet.
Research presented at DAA’s 2016 National Conference compared the 5:2 diet to a standard reduced kilojoule diet, amongst a small group (24) of obese male war veterans. After six months, researchers reported both groups lost weight, and reduced their waist circumference, but there was no significant difference between the two groups.
Interestingly, weight loss slowed at the three-month mark for both groups, which was when dietitian follow-up tapered out, showing support may be the key element in continuing success.
Another recent study, published in the Journal of the American Medical Association (JAMA), compared alternate-day fasting to standard kilojoule restriction, to assess whether the former was more effective in weight loss and maintenance. The randomised control trial divided 100 obese adults into one of three groups – an alternate day fasting group, a kilojoule restriction group, or a control group with no intervention.
The group was followed for 12 months, and researchers found similar results for weight loss amongst the alternate-day fasting group, and those in the kilojoule-restriction group. There were also no significant differences between the intervention groups in blood pressure, triglycerides, fasting glucose or insulin, and insulin resistance.
Interestingly, the alternate-day fasting group also had a high dropout rate, and struggled to meet their recommended intake, while the kilojoule-restricted group generally met theirs.
Why do it?
Evidence shows intermittent fasting is as effective (but not better) than a standard reduced-kilojoule diet for weight loss, and may be useful for weight maintenance. Daily dieting is challenging, and for some people, the idea of ‘watching what you eat’ for only a set number of days, or hours in a week is mentally more appealing than other alternatives. The process of doing so may also encourage a more ‘mindful’ approach to eating, with followers being more attuned to hunger and fullness cues.
Why shy away from it?
Intermittent fasting focuses on kilojoule-counting (quantity), rather than the kinds of foods eaten (quality). While being a healthy weight for you is one measure of health, making small tweaks to your current diet, like focusing on eating more fruit and vegetables, can lead to big changes in your health. Given that less than seven per cent of Australians currently meet the target of five serves of vegetables each day, there are clear improvements we can make to our everyday eating patterns – and for most Australians, this should be the focus.
It’s also not suitable for everyone. Children and teenagers, athletes and highly-active people, those with diabetes, pregnant women, and people with eating disorders should all steer clear of fasting diets.
Intermittent fasting diets may also lead to some unpleasant side effects, like fatigue, feeling foggy-headed, affected mood, feeling ‘hangry,’ constipation, and headaches.
The bottom line:
In reality, any ‘diet’ that encourages an energy deficit – that is, means you take in fewer kilojoules than you expend through exercise and daily activities, will result in weight loss. But for lasting, long-term health benefits, it’s best to find an eating pattern that you enjoy, and can stick with.
We’re all different, and there is no one-size-fits all approach when it comes to eating. While intermittent fasting may suit some people, it’s not a magic bullet to improved health.
For nutrition advice tailored to you, see an Accredited Practising Dietitian. They’re passionate about translating the latest evidence on healthy eating into practical, everyday advice and tips, and can support you on your journey towards better health.
Bariatric surgery (March 2017)
In recent media reports, Monash University researchers suggest (laparoscopic adjustable) gastric banding should be considered for overweight people with diabetes[i] – not just those with a body mass index (BMI) of 35 or more, as per current guidelines[ii]. The research paper has sparked debate on whether the current guidelines for bariatric surgery should be reviewed.
What is clear is that good nutrition is crucial at all times – in attaining good health and managing weight on an ongoing basis and, in those who undergo bariatric surgery, pre- and post-operatively. Accredited Practising Dietitians (APDs) provide extensive education, counselling and support throughout the weight loss journey, as weight management does not stop with bariatric surgery.
What is bariatric surgery?
Bariatric surgery (or weight loss surgery) aims to reduce intake by restricting gastric capacity and/or reducing exposure to the area in the small bowel where nutrients are absorbed. A number of different bariatric procedures are used in Australia, and gastric banding is one of these.
Australia’s current guidelines
Bariatric surgery is an evolving area, and this new research from Monash University is certainly food for thought. It suggests gastric banding as a powerful tool for people who are overweight (rather than obese) with type 2 diabetes – improving measures such as blood glucose control (HbA1C) and HDL (good) cholesterol.
The current National Health and Medical Research Council (NHMRC) guidelines say that bariatric surgery may be considered in adults with a BMI >40, or in those with a BMI >35 together with associated medical conditions that may improve with weight loss. In both instances, an individual’s unique situation needs to be taken into account.
Diet and lifestyle changes should be the first port of call
Strong evidence tells us that diet and lifestyle changes should be the first option for improving health in people carrying excess weight. Most people need support over time to maintain such changes. This is where health professionals, such as APDs, have a lot to offer – using an evidence-based approach, and tailoring advice to each person.
Interestingly, some people who ‘fit the bill’ for bariatric surgery are malnourished. In fact, people who are overweight or obese are at risk of deficiencies in nutrients like iron and vitamins D, B12, E and C. For long-term good health (regardless of weight) consuming a wide variety of nutritious foods, in the right amounts, is vital in ensuring nutrient needs are met.
Considerations in undergoing bariatric surgery
- People considering bariatric surgery should be assessed on a case-by-case basis by a medical professional. While it is an effective treatment in aiding weight loss, it’s not a blanket solution suited to everyone.
- Bariatric surgery will only be effective in the long-term if it’s used in conjunction with healthy eating and regular physical activity. And people should be motivated, well-informed and compliant before being considered for surgery, as this will impact its long-term success.
- For the best results, people undergoing bariatric surgery must be managed by a team of healthcare professionals, including pre- and post-surgery follow-up with an APD.
Input from an Accredited Practising Dietitian is pivotal
Achieving long-term weight loss relies on weight management strategies being continued after bariatric surgery has occurred. APDs provide a long-term nutrition management plan and help set a realistic picture of life and eating after surgery, which in turn can help prevent additional weight gain. APDs also help people cope with the problems that can result from surgery – such as nutritional deficiencies, which can follow obesity surgery procedures that reduce dietary intake.
The bigger picture
Tackling overweight and obesity requires a comprehensive, coordinated and evidence-based approach to address prevention and treatment across the community. DAA believes this includes better access to APDs, through Medicare rebates and private health fund rebates, so people receive the support they need. It also involves better regulating food marketing, improving the Australian food supply, effective on-pack information, and a host of other actions.
[i] Wentworth JM et al. Five-year outcomes of a randomised trial of gastric band surgery in overweight by not obese people with type 2 diabetes. Diabetes Care. April 2017; 40.
The CSIRO low-carb diet (February 2017)
CSIRO has just launched a new diet book ‘The CSIRO low-carb diet’, by Associate Professor Grant Brinkworth and Accredited Practising Dietitian (APD), Pennie Taylor, based on their research.
DAA supports quality nutrition research, such as clinical studies from the CSIRO, as a way of better understanding how nutrition affects health. Accredited Practising Dietitians (APDs) have university-level qualifications in nutrition science and many APDs are working in nutrition research. Nutrition is an evolving area and the CSIRO research (and accompanying book) certainly provide food for thought. Read more in this Hot Topic.
The science underpinning the new CSIRO low-carb diet book
In their book, the CSIRO authors highlight a clinical study they conducted[i], involving 115 overweight or obese adults with type 2 diabetes – divided into two groups. They were randomly assigned to either:
- ‘Low carb diet’: 14% of energy as carbohydrate (<50g/day); 28% of energy as protein; 58% of energy as fat (<10% saturated fat); 24.7g fibre; or
- ‘High carb diet’: 53% of energy as carbohydrate (205g); 17% energy as protein; 30% energy as fat (<10% saturated fat); 31.1g fibre.
Both diets were equally restricted in energy (kilojoules).
Study participants were monitored over 12 months. Both groups received intensive nutrition support throughout the study period (dietetic visits every two weeks for 12 weeks, and monthly thereafter – translating to 15 sessions with an APD over 12 months), as well as exercise sessions three times a week.
At the end of the study, they found no difference between the ‘low carb diet’ group and the ‘high carb diet’ group, in measures such as:
- Weight (both groups lost about 10 kg)
- HbA1c* (reduced by 1% in both groups)
- Fasting glucose
- Blood pressure
- Total and LDL (bad) cholesterol.
However, the medication score and glycaemic variability both improved on the ‘low carb diet’, compared with the higher carbohydrate diet.
The HDL (good) cholesterol and triglyceride levels were also slightly better on the low carbohydrate diet. That is, HDL cholesterol was increased by 0.1mmol/L on the low carbohydrate diet and by 0.06mmol/L on the higher carbohydrate diet. And triglycerides were reduced by 0.4mmol/L and 0.01mmol/L, respectively.
In the book, the authors say ‘The CSIRO low-carb diet is specifically designed to ensure that it’s nutritionally complete and provides adequate intakes of all essential vitamins, minerals and trace elements’.
Their diet is one of many different low carb approaches that are currently popular. Australians should be aware that the research findings underpinning the CSIRO low-carb diet are specific to that diet, and cannot be generalised to other low carb approaches.
No one-size-fits all
The CSIRO research tells us that a low carbohydrate, high healthy fat diet may be one option for people with diabetes, but the truth is that there are many ways to have a healthy diet.
For example, research shows that a vegetarian diet, which is very high in carbohydrates, is just as effective as a low carbohydrate diet in improving blood glucose control (HbA1C). Similarly, Mediterranean-style diets, low glycaemic index (GI) diets and high protein diets have all been shown to also work in lowering HbA1C.
So, there is no one-size-fits-all approach for everyone, as we’re all different.
Support from an APD: Crucial in the CSIRO research (and more broadly)
The participants in the CSIRO study had access to regular professional nutrition support throughout the 12 month study period. DAA would like this to have been mentioned in the book, as well as in media stories promoting the launch of the book – as it is likely to have been crucial to the success of participants in both groups of the CSIRO study.
Participants in the CSIRO study had plenty of support, including:
- Tailored diet plans developed for them at the start of the study
- Consultations with an APD: every two weeks for 12 weeks, and monthly thereafter
- Key foods provided for the first 12 weeks, and after this (on alternate months) either further key foods or $50 vouchers to buy foods (in other words, healthy foods were subsidised)
- 60-minute exercise classes (free of charge) three days each week, for the duration of the study.
Having that tailored, professional advice and a regular touch point for support from an APD helps people to adhere to diet changes, and that’s a key finding from the CSIRO research.
This has been shown in other studies too. For example, studies comparing different diets, such as the 5:2 diet and a reduced-kilojoule diet, show that weight loss (for instance) slows once dietitian follow-up stops, regardless of the diet followed.
DAA would like to see better access to APDs, through Medicare rebates and private health fund rebates, so people can receive the tailored advice and support they need. At the moment, people with chronic medical conditions, such as diabetes, who are managed under a care plan through their GP, can access just five visits to allied health professionals (such as APDs) through Medicare – and for most people, that’s nowhere near enough.
See our previous Hot Topic on Low carb, high fat diets for diabetes.
*HbA1C is an average of our blood glucose levels over a period of weeks/months – and gives an indication of how well diabetes is being controlled.
[i] Tay J. et al. Comparison of low- and high-carbohydrate diets for type 2 diabetes: a randomized trial. American Journal of Clinical Nutrition. 2015; 102:780-90.
Fructose (October 2016)
Is fructose really a problem in Australia or has it been unfairly demonised? DAA believes the key issue in Australia is ‘added sugars’, rather than fructose. So a total avoidance of fructose, as recommended by some anti-sugar crusaders, is unnecessary. Find out why in this Hot Topic.
The sugar fructose has been the subject of considerable media attention, most of which has been negative. Critics link dietary fructose with health risk markers such as obesity, high triglyceride (blood fat) levels and insulin resistance, and claim it is less satiating than other sugars. The fact it’s processed in the body via a different metabolic pathway is often blamed.
Where is fructose found?
Fructose is a type of carbohydrate naturally found in fruit, fruit juice, vegetables, syrups (such as maple syrup) and honey.
Fructose also makes up half (50 per cent) of sucrose, or ‘table sugar’ (the other 50 per cent is glucose). In Australia, foods such as biscuits, cakes, chocolate and lollies, and sweetened beverages such as carbonated soft drinks and sports drinks, contain added sucrose – of which fructose is a part. Highly-processed foods such as these are major dietary sources of fructose in Australia.
In some countries, high fructose (55 per cent) corn syrup is used to sweeten foods, whereas in Australia, manufacturers use sucrose (cane sugar) and glucose syrup (from wheat).
So is fructose really a problem in Australia?
Some studies suggest the source of fructose in foods – whether naturally present or added –could make a difference. That is, high intakes from added sources may adversely affect body weight, insulin sensitivity, and blood lipids – but this pattern is not seen with naturally-occurring fructose. However, results are not consistent between studies[i].
Like most nutrients or food components, the quantity we eat or drink is key. Most of the research looking at the effects of fructose has used very high doses of pure added fructose – much more than what people would typically eat.
Research tells us that a moderate fructose consumption of ≤50g/day or around 10% of energy has no adverse effect on lipid and glucose control[ii]. Similarly, ≤100g/day does not influence body weight. In other words, to be harmful to health, people would need to eat at least 50g of pure fructose on top of their regular diet. The reality is that few Australians eat pure fructose, let alone in the amounts required to cause adverse health problems.
How much is too much?
There are no specific recommendations for fructose intake, but there are for free and added sugars in general.
The World Health Organisation (WHO) recommends cutting free sugars (which includes added sugars, honey, syrups and fruit juices) to less than 10 per cent of total energy (or kilojoule) intake, preferably 5 per cent. For an adult eating around 8,700 kJ a day, this means no more than 51g, which is about 13 teaspoons a day. Children, who have lower energy requirements, would need to eat fewer teaspoons to meet WHO recommendations.
The latest Australian Health Survey[iii] tells us that in 2011-12, Australians were eating, on average, 60g (about 14 teaspoons, or 10.95% of energy) of free sugars a day. But this is an average – and some people, including children and teenagers, are eating a lot more.
Australians are not eating enough fruit: A food naturally containing fructose
Some anti-sugar advocates warn against fruit, due to its fructose content.
But many Australians need to eat more fruit, which contains naturally-occurring sugars including fructose and glucose, along with important nutrients like fibre, vitamins, minerals and phytonutrients. In fact, the dietary fibre in whole fruit helps to fill us up, which prevents us from eating too much. So we only obtain a small amount of fructose from fruit, which is not going to blow the fructose budget. Our most recent National Health Survey found just 52 per cent of Australians meet the minimum recommendations for fruit (two serves per day for most adults)[iv].
In line with the recommendations of the Australian Dietary Guidelines, the Dietitians Association of Australia (DAA) recommends choosing fruit juice and dried fruit only occasionally. If you have these, choose juice with no added sugar and limit this to no more than 125mL at a time, and 30g of dried fruit is considered a serve. Both are concentrated sources of sugars, and are easy to over consume.
A note on fructose malabsorption
Some people have difficulty absorbing fructose in their small intestine, which can result in side-effects such as bloating, abdominal distention and wind. A hydrogen breath test can be used to diagnose fructose malabsorption. Limiting foods with fructose, such as by following a low FODMAP diet, can improve symptoms. For people who are concerned about fructose malabsorption, DAA recommends seeking advice and support from a health care professional. For example, an Accredited Practising Dietitian can assess an individual’s diet and provide tailored dietary advice (including guidance on a low fructose diet), while also ensuring nutrition needs are met.
Limiting added sugars is the key
DAA believes all added sugars need to be the focus. That is, people should aim to limit added sugars (such as glucose/dextrose, sucrose, rice syrups etc), including (but not only) added fructose.
Table sugar, or sucrose, is made up of glucose and fructose (50:50) and is in fact a huge contributor to fructose consumption. Many people use it at home and it’s also used to sweeten many commercially-produced foods, such as cakes, biscuits and sweetened breakfast cereals.
In fact, the Australian Dietary Guidelines specifically recommend limiting intake of foods containing added sugars such as confectionary, soft drinks, fruit drinks, cordials, vitamin waters, energy drinks, sports drinks, biscuits and cakes.
Sadly, recent figuresi[v] indicate that Australians are consuming nearly a third of their daily energy (or kilojoules) form discretionary foods, which includes foods containing added sugars. And 75 per cent of 9-18 year olds currently get more than 10 per cent of their kilojoules from added sugar, but fail to consume even the minimum recommended quantities from other core food groups such as fruit, vegetables, wholegrains, milk, cheese or yoghurt.
So the key issue in Australia is ‘added sugars’, rather than fructose. A total avoidance of fructose, as recommended by some anti-sugar crusaders, is unnecessary.
Focussing on a single ‘dietary villain’ is easy, but the concept has major flaws. You don’t need to avoid sugars (or fructose) completely for good health, but it’s sensible to limit intake of foods which contain added sugars (whether that be fructose, glucose, sucrose or any other form of added sugar), and also provide little or no nutritional value.
See the Australian Dietary Guidelines at www.eatforhealth.gov.au
[i] From Practice-based Evidence in Nutrition (PEN): References available on request.
[ii] Rizkalla SW. Health implications of fructose consumption: A review of recent data. Nutrition & Metabolism 2010; 7:82. Available at: http://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-7-82
[iii] Australian Bureau of Statistics. Australian Health Survey: Consumption of Added Sugars 2011-2012. Available at: http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/4364.0.55.011main+features12011-12
[iv] Australian Bureau of Statistics. National Health Survey: First Results 2014-2015. Available at:
[v] Australian Bureau of Statistics. National Health Survey: First Results 2014-2015. Available at:
Misleading media reports on high fat, low carbohydrate diet for Australians (May 2016)
The Dietitians Association of Australia (DAA) is disappointed with recent media reports, including a piece on Channel 7 News (23 May 2016) titled ‘Fatty foods don’t make you fat, but sugar is off the menu: Dieticians (sic)’.
These alarmist reports contain many factual inaccuracies, with the information presented to Australians not in line with the latest evidence.
Sadly, such reports only confuse the Australian public about what to eat for good health. DAA, and the 5,900 members the Association represents, take very seriously our responsibility of promoting accurate, balanced and complete nutrition information to the public.
We are deeply concerned that yesterday’s media reports suggest ‘dietitians’ agree with the statements in the news reports, as this is not the case.
Check the qualifications of anyone providing nutrition advice
DAA recommends checking the nutrition qualifications of anyone providing dietary advice. As with any field, it’s important that advice is provided by those qualified to do so, working within their scope of practice.
Accredited Practising Dietitians (APDs) are nutrition scientists with a minimum of four years’ university study behind them. APDs assess individuals and provide tailored, expert nutrition advice and support, based on the latest evidence. They undertake ongoing training and development to ensure they are up-to-date, and like other health professionals, are bound by professional standards and accountable for the advice they provide.
Unfortunately, an APD was not interviewed for the Channel 7 News story, or other associated stories.
The Australian Dietary Guidelines: Evidence-based guidelines Australians can trust
It is without basis, and grossly misleading, to claim the Australian Dietary Guidelines (ADG) are ‘making us sick’ (as was the suggestion in the Channel 7 News story).
The evidence-based ADG, which were developed by independent experts in nutrition, working with the National Health and Medical Research Council, provide a framework for healthy eating – and DAA supports these recommendations for the healthy population. An assessment of more than 55,000 studies informed the recent review of the 2013 Australian Dietary Guidelines.
The ADGs are similar to evidence-based guidelines around the world, across a range of cultures and food systems – but our Guidelines are specific to issues and concerns within the Australian population.
Regarding fat and carbohydrates, the nutrition science tells us:
- When it comes to carbohydrates, good-quality choices (such wholegrains and legumes) can be part of a healthy diet, and are in fact recommended to help meet daily fibre targets. When it comes to wholegrains, for example, there is strong evidence to link wholegrain intake with lower body mass index, smaller waist circumference, and reduced risk of being overweight.
- A diet high in saturated fat is a risk factor for heart disease, one of our nation’s biggest killers. Saturated fats tend to increase LDL (unhealthy) cholesterol in the blood and current evidence suggests these should be eaten sparingly to minimize the risk of heart disease. Instead, foods that are rich in unsaturated fats (such as monounsaturated and polyunsaturated fats) are recommended.
DAA agrees with the message to limit manufactured (or processed) foods that provide little nutrition value – this is what the ADG also recommend, so this is nothing new. The ADG encourage Australians to choose whole foods, such as vegetables, legumes, fruit, lean meats and eggs. And for foods within a package, DAA recommends Australian read the nutrition information panel to be able to make informed choices. An APD can work with people on these, and other strategies, to help them achieve a healthy eating plan, tailored to their individual needs.
DAA points out that the ‘panel of global dietary experts’ mentioned in yesterday’s media reports consist of the UK-based National Obesity Forum and the Public Health Collaboration – whose views on saturated fat have been questioned by the UK’s Royal College of Physicians and Public Health England. See the response by Public Health England to the National Obesity Forum and Public Health Collaboration opinion paper.
DAA appeals to journalists reporting on diet-related issues in Australia to report responsibly, and to source and discuss facts with local experts.
Coconut oil (April 2016)
Some recent discussion has centred on the potential benefits of coconut oil. In reality, foods rich in saturated fat (such as coconut oil) are linked with a higher risk of heart disease, and eating high fat foods, which are therefore higher in energy, makes weight control more difficult.
There is a great deal of conflicting advice about diet and nutrition – often provided by people with no nutrition qualifications. Sadly, the more controversial claims often create more hype and a greater following in the community.
Recently, there has been discussion around the potential benefits of coconut oil. In reality, foods rich in saturated fat (such as coconut oil) are linked with a higher risk of heart disease, and eating high fat foods, which are therefore higher in energy, makes weight control more difficult.
The New Zealand Heart Foundation has recently issued an evidence-based statement on coconut oil and heart health.
In Australia, the Heart Foundation recommends avoiding coconut oil due to its high saturated fat content (around 85-90 per cent saturated fat). Saturated fat increases total cholesterol and LDL (bad) cholesterol, and increases the risk of heart disease. Saturated fats are not an essential part of the human diet.
The Dietitians Association of Australia (DAA) encourages people looking to lose weight and lower their risk of heart disease to eat a balanced, healthy diet in line with the recommendations of the Australian Dietary Guidelines. When it comes to diet and health, there is no ‘magic bullet’, and no single food that causes disease. We need to look at the whole diet.
DAA also encourages people seeking expert nutrition advice to look for the Accredited Practising Dietitian (APD) credential when choosing a nutrition professional. Anyone can call themselves a ‘dietitian’ – even people with little or no nutrition qualifications. But the APD credential is the quality standard for nutrition and dietetics services in Australia, as recognised by the Australian Government.
DAA acknowledges that more research on this topic needs to be conducted, and until there is sufficient evidence, DAA supports the current Australian Dietary Guidelines.
For more information see the Saturated or not: Does type of fat matter? webcast by the Harvard School of Public Health.
DAA’s Smart Eating Fast Facts on coconut oil also contains further information on this topic.