Hot Topics

DAA’s ‘hot topics’ summarise the latest research and current thinking on topical nutrition issues in the media.

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 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 certainly is food for thought. Read more in this Hot Topic.

The science underpinning the new CSIRO low-carb 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 energy (kilojoule) restricted.

Study participants were monitored over 12 months. Both groups received intensive nutrition support throughout the study period (every two weeks for 12 weeks, and monthly thereafter – meaning 15 sessions with an Accredited Practising Dietitian 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, HDC cholesterol was increased by 0.1mmol/L on the low carbohydrate diet and by 0.06mmol/L on the higher carbohydrate diet. 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. But it’s important that Australians realise that the research findings around the CSIRO low-carb diet are specific to their 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 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 study. DAA would like to have seen this 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 (such as the weight loss seen) of participants in both groups of the CSIRO study.

Participants in the CSIRO study had:

  • 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 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.

Bottom line

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:

http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.001~2014-15~Main%20Features~Daily%20intake%20of%20fruit%20and%20vegetables~28

[v] Australian Bureau of Statistics. National Health Survey: First Results 2014-2015. Available at:

http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.001~2014-15~Main%20Features~Daily%20intake%20of%20fruit%20and%20vegetables~28

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.

The Centre for Evidence-based Medicine has published a critique, and the Guardian newspaper has also reported on the backlash against the National Obesity Forum’s dietary recommendations.

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.

Meat and cancer (October 2015)

The International Agency for Research on Cancer has released an evaluation on red and processed meats and cancer. This Hot Topic outlines IARC’s key findings, and the Australian Dietary Guidelines recommendations regarding red and processed meats.

A group within the World Health Organisation, the International Agency for Research on Cancer (IARC), has released its evaluation on red and processed meats and cancer, leading to widespread media attention in Australia.

When it comes to red meat, DAA supports the recommendations of the Australian Dietary Guidelines (ADG). The Guidelines recommend up to 455g cooked lean red meat per week and also recommend limiting processed meat. To reduce risk of cancer, DAA recommends a healthy diet, including eating plenty of vegetables and legumes/beans, as well as fruit and grain foods (especially wholegrain), achieving and maintaining a healthy weight, and being physically active.

Summary: The IARC evaluation

The IARC evaluation is part of the organisation’s Monograph Program, which identifies and evaluates environmental causes of cancer in humans.

Key findings from the IARC evaluation:

  • Red meat as ‘probably carcinogenic to humans (Group 2a), based on limited evidence that the consumption of red meat causes cancer in humans and strongmechanistic evidence supporting a carcinogenic effect’. This means that red meat was not established as a cause of cancer, because the IARC Working Group considered the evidence in humans to be limited and they could not exclude confounding from other diet and lifestyle factors (such as overweight/obesity, smoking, alcohol and low intake of vegetables, wholegrains and legumes).
  • Processed meat was classified as carcinogenic to humans (Group 1), based onsufficient evidence in humans that the consumption of processed meat causes colorectal cancer. This means consumption of processed meat causes cancer because the majority of the Working Group considered the evidence sufficiently consistent to conclude that any other explanation for increased risk associated with processed meat was unlikely. Importantly, IARC notes that the risk is small and related to portion size and does not carry the same risk as other substances in Group 1 such as tobacco or sunshine.
  • The Working Group were not able to reach a conclusion about a safe level of meat consumption and considers it the role of each country to set their own red meat recommendations based on a careful evaluation of the risks and benefits of red meat for their specific populations.

Australian Dietary Guidelines: Evidence-based recommendations

When it comes to red meat, DAA supports the recommendations of the Australian Dietary Guidelines(ADG). The Guidelines recommend up to 455g cooked lean red meat per week (which is equivalent to one serve (65g) per day, or two serves (130g) every second day). They also recommend limiting processed meat (such as ham and bacon) to reduce some of the health risks associated with eating these foods.

Lean red meat has a valuable place in the Australian diet, providing an important source of iron, zinc and vitamin B12. However, regular consumption of greater than 100-120g/day of cooked red meat has been linked with an increased risk of colorectal cancer.  So it’s a bit like sunlight – a little bit is good for you, but don’t overdo it: 455g per week of cooked lean red meat represents the ideal amount for Australian adults.

To get all of the nutritional benefits from meat and to help you stay healthy, DAA recommends:

  • Limit your weekly intake of lean red meat to a maximum of 455g
  • Choose lean cuts of meat and trim off the visible fat
  • Limit your intake of processed meats*
  • Try to avoid burning or charring meat, and if barbequing, using a marinade can help.

And for people confused about any part of their diet, DAA recommends seeking advice and support from an Accredited Practising Dietitian (APD).

(*Note: In the ADG ham, bacon, sausages and deli or luncheon meats are not recommended, however, lean, lower-salt sausages may be included as part of the 455g/week recommendation).

Diet, lifestyle and cancer

Evidence shows that being overweight, having a poor diet, drinking alcohol and doing little or no exercise all increase your risk of developing some types of cancer, such as oesophagus, stomach and bowel.

To reduce cancer risk, DAA recommends:

  • Eating plenty of vegetables and legumes/beans, as well as fruit and grain foods (especially wholegrain)
  • Being a healthy weight – which includes balancing the amount of energy (kilojoules) you take in with the amount of energy you expend each day
  • Being physically active
  • Limiting alcohol consumption (if you choose to drink)
  • Limiting intake of processed meats.

To effectively reduce cancer risk, these lifestyle factors should be targeted in combination.

World Food Day 2015 (October 2015)

World Food Day, which is recognised globally on 16 October, is a day of action against hunger, malnutrition and poverty. DAA is supporting World Food Day again in 2015, to increase awareness of these issue in developing countries – and also in our own backyard.

World Food Day, which is recognised globally on 16 October, is a day of action against hunger, malnutrition and poverty.

According to the Food and Agricultural Organization (FAO) of the United Nations, around 795 million people (just over one in nine) are undernourished globally. Around 60 per cent of the hungry in the world are women and almost five million children under the age of five die of malnutrition-related causes every year.

The Dietitians Association of Australia (DAA), the peak body for dietitians, is supporting World Food Day again in 2015, to increase awareness of hunger in developing countries – and also in our own backyard.

DAA proudly continues to work with Foodbank, Australia’s largest food relief organisation, to address hunger at home.  Foodbank’s 2013 End Hunger Report provides an up-to-date picture of the issue of food insecurity in Australia, highlighting that around 2.2 million Australians live in poverty.

DAA recognises that healthy people depend on healthy food systems and the Association supports approaches which aim to provide secure, sustainable and affordable food choices based on a variety of food groups recommended by the Australian (and international) Dietary Guidelines.

Whilst quantity of food is important, to meet energy (or kilojoule) needs, a balanced and diverse selection of foods is also essential to meet people’s nutrient needs.

To commemorate World Food Day 2015, DAA members have shared their budget-friendly recipes to create ‘The Thrifty Cook’ recipe book. DAA also continues to encourage Australians to work hard to reduce food waste.

Low carb, high fat diets for diabetes (July 2015)

What’s a low carb, high fat diet? And is it really the best if you have diabetes? In this Hot Topic, DAA summarises 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 1970’s), 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?

The primary purpose of this Hot Topic is to summarise the key conclusions of the best available evidence, based on two systematic review and meta-analysis papers (references 5 and 6 listed below).

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 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, personal and cultural preferences, their access to healthy choices, and their 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].

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 impossible to meet all known nutrient and fibre targets, and therefore could not be recommended for diabetes management in the long term2.

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].

In its ‘Carbohydrates and Health Report’ (2015)[4], the Scientific Advisory Committee on Nutrition (UK) recommended that the dietary reference value for total carbohydrates should be maintained at an average population intake of around 50% of total dietary energy.

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[5]. 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 (2014)[6] 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 CHO 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 CVD 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. Unfortunately, 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 resistance2.

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 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 diabetes (type 2). Dietitians also recommend people with diabetes spread their carbohydrate food choices over the day, to assist with glycaemic control.

According to Diabetes Australia[7], very low carbohydrate diets are not recommended for people with diabetes. The organization states: ‘If you eat regular meals and spread your carbohydrate foods evenly throughout the day, you will help maintain your energy levels without causing large rises in your blood glucose levels’ (Diabetes Australia website, 2015). Diabetes Australia recommends people with diabetes eat moderate amounts of carbohydrate and include high-fibre foods that also have a low glycaemic index (GI).

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[8], data suggests on average Australians are consuming about 222g of carbohydrate per person per day, making up 43.5% of total energy intake (Australian Bureau of Statistics, 2011-12). This indicates a ‘Moderate’ carbohydrate intake across the population. Furthermore, for Australians, this amount has decreased since the last National Nutrition Survey in 1995.

What if I don’t have diabetes? Is this diet right for me?

The Australian Dietary Guidelines have been designed for healthy populations and suggest people have from 45%, and up to 65%, of their total energy intake from carbohydrate foods. This is purposefully a wide range, to account for factors such as a person’s level of physical activity and personal food preferences. The Dietitians Association of Australia (DAA) recommends seeking advice from an Accredited Practising Dietitian (APD) before dramatically altering your diet or that of your family – especially if you are considering cutting out whole food groups.

A word on saturated fats

In ‘Low Carb, High Fat’ diets, a variety of fats have also been suggested as replacements for carbohydrate foods. Some LCHF diets promote foods like coconut oil and animal fats (such as lard and butter), often suggesting these are more ‘natural’ sources of fat. DAA believes this is misleading.

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. The Australian Dietary Guidelines recommend Australians limit intake of foods high in saturated fat.

Foods high in saturated fat include:

  • 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 final word

A Low Carbohydrate, High Fat diet may be used by some nutrition professionals in the short term to achieve particular health goals, but the effectiveness and safety of the diet has not been examined in the longer term. An argument for the use of the diet can potentially be supported by ‘established principles in biochemistry and physiology’3, however long-term randomised controlled trials with consistent dietary methodology are lacking.

Therefore, this diet type remains controversial – and DAA believes more research is required on the safety and efficacy of such as diet, in people with diabetes and the general population. 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. DAA recommends people with diabetes seek advice from a health professional before dramatically changing their diet.


[1] Evert et al (2014) Nutrition Therapy Recommendations for the Management of Adults With Diabetes. Diabetes Care Volume 37, Supplement 1; p S120-143.

[2] Dworatzek et al (2013) Canadian Diabetes Association Clinical Practice Guidelines Expert Committee, Canadian Journal Of Diabetes, Vol. 37 Suppl 1, p S45-55.

[3] Feinman et al (2015) Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base Nutrition 31; p 1–13.

[4] Scientific Advisory Committee on Nutrition (2015). Carbohydrates and Health. The Stationary Office Limited. Available from: www.tsoshop.co.uk

[5] Ajala et al (2013) Systematic review and meta-analysis of different dietary approaches to the management of type 2 diabetes. American Journal of Clinical Nutrition, Vol. 97 Issue 3, p 505-516.

[6] 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.

[7] Diabetes Australia: https://www.diabetesaustralia.com.au/what-should-i-eat accessed July 2015.

[8] 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 July 2015.

Written in July 2015.

Dietitians support the fight against hunger (May 2015)

A new report, released on World Hunger Day (28 May 2015), reveals many Australian children are arriving at school hungry or without having eaten breakfast, affecting their potential both inside and outside the classroom.

Foodbank Australia’s ‘Hunger in the Classroom’ report highlights that hunger is an ongoing crisis in Australia, including among school-aged children, and food insecurity is a sad reality in many Australian households, and the problem seems to be getting worse.

The report reveals three students in every class will arrive at school hungry, and teachers say this impacts learning, concentration, energy levels, and behaviour. The report found children in regional and rural areas are more likely to arrive at school hungry.

The Dietitians Association of Australia (DAA) believes all Australians, as a basic human right, should have access to a safe, adequate and healthy food supply.

Sadly, not being able to access nutritious foods has a huge impact on health (with a greater risk of diseases like diabetes, cancer and heart disease), and shortens life expectancy. DAA is concerned with the long-term effect of hunger and food insecurity, especially in light of these alarming figures in children.

DAA and Foodbank, the nation’s largest hunger relief organisation, are working together to help address food insecurity in Australia. DAA believes partnerships between key groups, such as the food industry, government and charities, are needed to help address food security issues.

DAA applauds Foodbank’s activities to address food insecurity in Australia, including their School Breakfast Program, which strives to supply balanced food choices, with an emphasis on healthy staples like fruit, vegetables, milk and bread.

World Hunger Day 2015 is about raising awareness of the extreme hunger and poverty affecting millions of people around the world.

More information:

Hunger in the Classroom Report

Smart Eating Fast Facts: Breakfast – how to eat brekkie like a boss!

Obesity surgery (April 2015)

Fresh calls for obesity surgery to be publicly funded have been reported in the media. DAA believes obesity surgery can play a role in aiding weight loss in severely obese people, but dietitians need to be involved for the best outcomes. DAA also believes more investment is needed in preventing overweight and obesity through good nutrition.

Recent media reports have outlined a call by the Australian Medical Association (AMA) Qld for publicly funded bariatric surgery for morbidly obese people. The recommendation is part of the AMA Qld’s five-year Health Vision strategy.

The Dietitians Association of Australia (DAA) believes obesity surgery can play an important role in aiding weight loss in severely obese people, where diet and lifestyle approaches have not been sufficient to achieve long-term weight loss.

However, this approach will only be effective in the long-term when used in conjunction with healthy eating and regular physical activity.

Dietetic input is pivotal to the success of obesity surgery. In fact, recent research published in the journal Surgery for Obesity and Related Diseases showed structured nutritional counselling after bariatric surgery can help in achieving weight reduction[i].

For the best results, obesity surgery must be managed by a team of healthcare professionals, including pre- and post-surgery follow-up with an Accredited Practising Dietitian (APD). And people considering obesity surgery should be assessed on a case-by-case basis by a medical professional.

DAA has made overweight and obesity a top priority, and is calling for a comprehensive, coordinated and evidence-based approach to address prevention and treatment across the community.

Background

Obesity surgery, also known as bariatric surgery, may be recommended in conjunction with lifestyle changes to aid weight loss in very obese people, that is people with a BMI >40, or BMI >35 in people with associated medical conditions. It is designed to limit the amount of food (and therefore energy) eaten, or to cause malabsorption of fat, or both.