Busting Myths about Grain Foods & Weight Loss

Want fast weight loss? Or has a new celebrity diet caught your eye?

Don’t fall for diet fads, or weight loss fast-fixes, is the health warning from the Grains & Legumes Nutrition Council (GLNC).

GLNC’s Michelle Broom, Accredited Practising Dietitian and Nutrition Program Manager says: “People are often spurred on to lose weight by the impending need to fit into a dress, look good for a special occasion or be bikini ready for a beach holiday. It’s this urgency that finds them grasping at straws, looking for a quick fix.

“The truth is individual testimonials often make dramatic claims and don’t end up delivering promised weight loss for others.

“Weight loss can be achieved without the fads, or succumbing to movements which encourage cutting whole food groups from your diet. It’s true that sustainable weight loss won’t happen overnight, but by taking a sensible approach, you won’t just lose the weight but keep it off too,” she said.

GLNC debunks five common myths about fad diets, misconceptions about eating grains and going gluten-free. 

MYTH ONE: Eliminating whole food groups is the key to weight loss.

FACT: The best thing for a healthy body is a balance of foods from all food groups. For weight loss, limiting foods that are high in calories but lack essential nutrients is important, and portion control is also key to sustainable weight loss.

MYTH TWO: A low-FODMAP diet is a healthy diet for all.

FACT: A low-FODMAP diet is not for the long term. It is designed as a short term (2-6 weeks), therapeutic elimination diet, often used to control Irritable Bowel Syndrome and other gut-related issues.  It requires the supervision and support of an experienced Accredited Practising Dietitian and is not for the general population.

MYTH THREE: Carbohydrates make you fat.

FACT: Quality grain foods such as whole grain bread and high fibre breakfast cereals can help with weight management. These foods are linked with a smaller waistline and greater chance of being a healthy weight. In addition, if you’re hitting the gym to boost your weight loss, you need carbs in your diet. In fact, keeping grain foods in your weight loss diet will provide the nutrients to help your metabolism.

MYTH FOUR: A low carb, high fat (LCHF) diet is the secret to slimming.

FACT: LCHF diets are not a more effective way of keeping weight off long term.  LCHF diets are yet to be proven to provide adequate nutrition, be sustainable and prevent disease across the lifespan. In fact, LCHF diets represent a radically different eating pattern to the foods shown by an analysis of the whole scientific evidence base. Diets such as LCHF that restrict fibre and nutrient rich carbohydrate foods have been linked with a 30% increased risk of early death.

MYTH FIVE: A gluten free diet will make you thin.

FACT: Many gluten free foods contain more calories than gluten containing foods as they often contain higher amounts of fat and sugar to make them taste better. Gluten free products are often made with ingredients such as potato starch or tapioca flour, resulting in products lower in fibre and whole grain which are important for digestion and metabolism. Unless medically diagnosed with coeliac disease or gluten intolerance, a gluten free diet provides no nutritional or health benefit to individuals.

Highlights from the Nutrition Society of Australia Annual Scientific Meeting

GLNC was one of the over 250 participants gathered in Hobart in the last week of November to hear the latest research on the link between food and health at the Nutrition Society of Australia Annual Scientific Meeting. GLNC has picked just some of the highlights to share with you.

‘Is Dissemination the Weakest Link in the 2013 Australian Dietary Guidelines?’
Dr Anita Lawrence from Dairy Australia presented the findings of a survey of Australian General Practitioners (GPs). The survey of 300 GPs was conducted in 2014 and compared to a survey of a sample from the Australian population. GP respondents indicated 31% of consultations involved the provision of nutrition advice. However, only 13% of the GPs were familiar with the 2013 Australian Dietary Guidelines, with female GPs more aware then male GPs. This was similar to the sample of the general population with 12% reporting awareness of the Australian Dietary Guidelines. While GPs rated their own confidence in their nutrition knowledge as 7 out of 10, only 8% were able to correctly identify dairy requirements for teens.

Nutrient Intakes of People on a Palaeolithic Diet
A small study of 39 healthy women compared the nutrient intakes of those on a Palaeolithic diet compared to those on a diet recommended by the Australian Dietary Guidelines. Participants followed the diets for four weeks and food intake was not restricted. The Palaeolithic group had a reduced intake of calcium and the B vitamins thiamin and riboflavin, with increased intakes of Vitamin C, E and beta-carotene.

Latest Insights on the Mediterranean Diet
Associate Professor Catherine Itsiopoulos, Head Dietetics and Human Nutrition at La Trobe University, gave an overview of the latest research on the Mediterranean diet. She described how the understanding of heart disease has shifted and it is now understood that low grade inflammation and oxidative stress are the key indicators of heart disease rather than lipid accumulation.  In light of this she suggested that perhaps it is not what we are eating that we should be focussing on, but what we’re not eating.

Dr Itsiopoulos suggested it is perhaps through the effect of polyphenols on chronic inflammation and oxidative stress that the Mediterranean diet is working to reduce risk of cardiovascular disease. She used the recent PREDIMED study to demonstrate this. The PREDIMED study, a large randomized clinical trial of 7,000 people investigating the effect of a Mediterranean Diet on cardiovascular disease (CVD) risk over 5 years, found 30% reduction in CVD mortality.  However, a recent reanalysis of the data to examine the relationship between polyphenol intake and health found a 37% reduction in CVD mortality with higher polyphenol intakes. The polyphenols with the greatest impact included isoflavones, the main source of which was legumes.  This is not surprising given the diet in the intervention included three 150g serves of legumes each week.

Dr Itsiopoulos also highlighted several additional studies currently underway in Australia investigating the effects Mediterranean diet on health including the MEDINA trial of people with non-alcoholic fatty liver disease, the AusMED intervention to reduce secondary acute myocardial infarction, as well as the HELFIMED study looking at the effect on mental illness.

At the end of the presentation an audience member suggested that while research indicates the health benefits of a Mediterranean diet it is perhaps not advisable to insist everyone follow the diet regardless of their cultural diet and that many diets from around the world have been shown to be linked to longevity and better health. Dr Itsiopoulos agreed but suggested that if we are looking for foods to include in a healthier diet for longevity there are common food elements to these diets including leafy green vegetables and legumes.

Fun Facts from the Scientific Meeting

• Australia’s Bogong moth has a similar nutritional profile as a handful of pumpkin seeds.
• Calcium bioavailability varies over life stages. For lactating mothers the availability is 80% compared to 30% for other adults.
• One hectare of land could produce 150 tonnes of insect protein per year (PROteINSECT study).

For more information about the Annual Scientific Meeting, visit www.nsa.asn.au.

Looking Beyond Nutrients to the Whole Package

The appetite for nutrient focused healthy eating messages in the media is insatiable. In 2014 this has been highlighted by the abundance of messages such as ‘quit sugar’ and ‘cut carbohydrate’ in the media. But is demonizing single nutrients really the path to a healthy diet?

Traditionally nutrition research has focused on the effects of individual nutrients and health. While this approach has shed ample light on our understanding of the mechanisms by which nutrients and other bio-active food components act within the body, the messages generated from such research have often unintentionally complicated the concept of healthy eating.

As we eat foods not nutrients, healthy eating messages which focus solely on the presence or absence of an individual nutrient are of limited use. Such messages do not comprehend that nutrients never act on the body in isolation, but rather are packaged with many other nutrients within foods which act together to influence health. For example, whole grains contain more than 26 health promoting nutrients and bio-active components and increasingly studies are showing that single these components do not simply act alone to protect health, but rather in concert. This explains why the observed benefit of the whole food package of whole grains often exceeds that explained by the action of each nutrient.^{(1, 2)}

In addition, a focus on a single nutrient in isolation also overlooks the impact of the food matrix (the structure of foods when consumed) and the overall the composition of the meal within a long term eating pattern. Each of which plays an important role on the impact of food on health.

Clearly nutrition is a very complex system and so focusing on a single nutrient in attempt to establish a healthy eating pattern is like trying to build a house with one tool. Constructing a healthy diet to reduce risk of disease across the lifespan requires a holistic, whole of diet approach as opposed to a reductionist nutrient focused solution. With advances in our understanding of the complexity of nutrition, health authorities and evidenced based practitioners have shifted the emphasis of dietary recommendations away from nutrients towards foods.

A focus on food was a key objective in the development of the 2013 Australians Dietary Guidelines. The Guidelines are designed not only to provide the nutrients essential for wellbeing but also to provide adequate amounts of the foods known to reduce the risk of chronic disease. Underpinned by a comprehensive review of over 55,000 studies, the Guidelines encourage Australians to consume a variety of nutritious, available, affordable and culturally appropriate foods from each of the five food groups: grains, mostly whole grain or high fibre; vegetables and legumes; fruits; lean meats, poultry, fish, eggs, nuts; and dairy.

In addition, with Australians waistlines increasing⁽³⁾, the Guidelines also focus on promoting a healthy weight; for the average size person doing light physical activity, adhering to an eating pattern which reflects the Guidelines will result in a daily reduction in energy intake and should result in weight loss.

Despite the recent re-focus of public health nutrition to foods not nutrients, single nutrient messages are taking centre stage in the media. Many may argue that the intent of messages such as ‘quit sugar’ or ‘low carb’ is to serve public health and encourage Australians to limit energy dense, nutrient poor food choices (i.e. soft drinks, pastries, biscuits, cakes and processed take away foods). However, the blunt nature of a nutrient focused recommendation inevitably results in vocal advocates of such messages also taking aim at foods and food groups such as fruits, whole grains and legumes, calling for the exclusion of these foods from the diet. This is despite the fact these foods are backed by the scientific evidence of being linked with better health.

As a result, these nutrient focused messages fail to reflect the evidence of the relationship between food and health. For those not convinced, such recommendations also contradict evidence from Blue Zones, the populations around the world with the best health and longest lives, who enjoy mostly plant based diets which include whole fruits, whole grains and legumes – each of which appear on the banned list of the latest quit sugar and low carb fads.

Just as past reductionist advice to reduce fat failed to achieve its intended outcome of encouraging people to eat more naturally low fat plant foods available at the time, current and future nutrient focused messages will fail to address the complex relationship between diet and diet related disease risk. Nutrition science continues to increase our understanding of the relationship between the food we eat and health and more often than not studies are demonstrating that it is more about all the elements of foods acting together rather than a single nutrient.

References

1. Fardet A. New Approaches to Studying the Potential Health Benefits of Cereals: From Reductionism to Holism. Cereal Foods World. 2014;59(5):224-9.
2. Parker TL, Miller SA, Myers LE, Miguez FE, Engeseth NJ. Evaluation of synergistic antioxidant potential of complex mixtures using oxygen radical absorbance capacity (ORAC) and electron paramagnetic resonance (EPR). Journal of agricultural and food chemistry. 2010;58(1):209-17.
3. AIHW. Australia's health 2014 Australia's health no. 14. Cat. no. AUS 181. Canberra: AIHW.2014. Available from: http://www.aihw.gov.au/australias-health/2014/

MEDIA RELEASE: Black Rice is the New Black

With a chewy texture and rich nutty flavour, black rice is the newest and trendiest health food on the market. Due to its exquisite burgundy-purple colour and nutrional appeal, expect to see this exotic grain served up in trendy restaurants and cafes across Australia.

According to the Grains & Legumes Nutrition CouncilTM (GLNC), the independent authority on the nutrition and health benefits of grains and legumes, black rice is a healthy alternative for people wanting to eat rice. It’s naturally gluten free, high in fibre and 100 per cent whole grain, making it a simple and delicious way to reach GLNC’s 48g whole grain Daily Target Intake (DTI).

Chris Cashman, GLNC Nutrition Project Officer, said rice is an important carbohydrate which helps to fuel the brain, support working muscles and vital organs.

“As well as being a great source of carbohydrate, it’s the high level of anthocyanin antioxidants in black rice that sets it apart from more well-known varieties like brown and white rice. In fact, black rice contains the same amount of health promoting antioxidants found in blueberries, but with less sugar and more fibre,” he said.

Renowned for centuries for both its attractive looks and perceived health benefits, black rice was once a rare delicacy. Even today the Chinese refer to the ancient grain as ‘forbidden rice’; cultivated for years in very small amounts only for the emperor’s consumption. It was believed black rice helped ensure good health and long life so was only reserved for the nobles. Although black rice was considered rare amongst the general public, today it’s a grain for everyone.

When to use it?
Often served as a dessert, like black rice pudding, most people are unaware of how else to use the ancient grain. Its vibrant colour makes black rice the ideal accompaniment to salads, sushi recipes or a nutritious addition to any grain based dish.  

How to cook it?
Black rice can be cooked in the same way as brown rice. Simply add 1 cup of rice to 2 cups of water or stock over a medium heat. Bring the water or stock to the boil and simmer for 25-30 minutes.

Where to buy it?
This ancient delicacy is becoming more readily available as manufactures, like SunRice, realise the grain’s nutritional and culinary potential amongst health conscious foodies. Black rice can now be found in supermarkets and specialty stores.

For more information and access to a selection of black rice recipes, visit the SunRice website https://www.sunrice.com.au/consumer/products/gourmet-rice/black-rice/. For more information on the nutrition and health benefits of black rice and other grain foods visit the Grains & Legumes Nutrition CouncilTM website www.glnc.org.au.

NEW SCIENTIFIC REVIEW: The Benefits of Breakfast Cereal Consumption

By Professor Peter Williams, Honorary Professorial Fellow at University of Wollongong and Adjunct Professor of Nutrition and Dietetics at the University of Canberra

Breakfast cereal eaters are more likely to have a healthier diet and to weigh less, and are less likely to suffer from certain diseases. That is the key finding of a systematic literature review of more than 230 papers over 30 years, which I undertook on behalf of the Australian Breakfast Cereal Manufacturers Forum and was recently published in the international peer-reviewed journal, Advances in Nutrition.

The findings of the review are significant – not only for the strength of the evidence – but because of the important role breakfast cereals play in delivering the health benefits of grain foods to Australian diets. According to the recent Australian Health Survey, around 43 per cent of Australians ate breakfast cereal, including ready-to-eat cereal (RTEC) and hot porridge, on the day of the survey.

It was clear from the research that regular breakfast cereal eaters have more nutritious diets, which are higher in vitamins and minerals and have a greater likelihood of meeting recommended nutrient intakes. Adults and children who eat breakfast cereal regularly also have higher wholegrain consumption each day.

The benefit of eating breakfast cereal for weight management was one of the strongest findings in the review. Regularly eating breakfast cereal is associated with a lower body mass index and a 12 per cent lower risk of being overweight or obese in both adults and children.

The review also found that high-fibre and wholegrain breakfast cereals help to improve bowel function, prevent constipation, and may lower the risk of diabetes and cardiovascular disease.  Key findings in this area include:

• Breakfast cereals high in soluble fibre (such as oat, barley or psyllium) help lower total and low-density lipoprotein (LDL) cholesterol. 
• Regularly eating wholegrain and high-fibre breakfast cereal is associated with reduced risk of type 2 diabetes (by 24 per cent) and cardiovascular disease (by 20-28 per cent). 
• Breakfast cereal plays an important role in bowel health, with evidence that high-fibre, wheat-based breakfast cereals help prevent constipation and improve bowel function.

Importantly, the review clarified questions about the contribution breakfast cereals make to sodium and total sugars intakes in the overall diet.

According to the research base, breakfast cereal eaters do not have higher sodium intakes than non-breakfast cereal eaters and there is no difference in their overall daily energy intake, total sugars intake or risk of overweight or obesity, whether children consume pre-sweetened breakfast cereals or other breakfast cereals.

The review is the first time the evidence relating to breakfast cereal and its impact on healthy diets, body weight, obesity, diabetes, cardiovascular disease and bowel health has been systematically assessed using the stringent National Health and Medical Research Council (NHMRC) criteria.

As a result of the systematic review, 21 graded summary evidence statements were established and in several instances, the evidence statements are as strong as or even stronger than that for fruit and vegetable consumption.

For more information, including a full summary report and link to the open access journal paper, visit http://www.cereal4brekkie.com.au/new-science/

GLNC notes the findings of this review align with the findings in the recently released Draft SCAN Carbohydrates and Health Report from the UK. This comprehensive review of the scientific evidence on the health effects of carbohydrate foods included a review of the effects of breakfast cereals containing at least 25% bran or 25% whole grain. The review concluded there is an 11% reduced risks of coronary events and 13% reduced risk of Type 2 Diabetes for every half serving of cereal. 

An Insight into Low FODMAP Diets

By Dr Jane Muir PhD (Head of Unit) and Dr Jane Varney PhD (Senior Research Dietitian) from the unit of Translational Nutrition Science, Department of Gastroenterology, Monash University.

The Department of Gastroenterology at Monash University conducts a major research program into the use of diet to treat irritable bowel syndrome (IBS).  IBS is characterised by chronic and relapsing symptoms, including lower abdominal pain and discomfort, bloating, wind, distension and altered bowel habits (ranging from diarrhoea to constipation), but with no abnormal pathology. The Monash team has discovered that IBS symptoms are relieved in 75% of sufferers, when a group of poorly absorbed short chain carbohydrates (FODMAPs, which stands for Fermentable Oligo-saccharides, Disaccharides, Mono-saccharides and Polyols), is restricted from the diet. FODMAPs are found in a whole range of foods including garlic, onion, wheat, rye, legumes, lentils and certain fruits and vegetables.

Owing to the restrictive nature of this diet, the Monash team emphasises that it is not appropriate for healthy individuals with no gastrointestinal disorders to follow a strict low FODMAP diet.  Rather, a low FODMAP diet should be trialled under the guidance of an experienced dietitian, for a period of 2–6 weeks. After this time and under the guidance of the dietitian, FODMAP containing food should be gradually re-introduced into the diet.

The team at Monash is focussed on translational research and has developed a number of tools which enable them to communicate their research findings to people suffering IBS. These include the Monash University Low FODMAP Diet Booklet and the Monash University Low FODMAP Diet App suitable for iPhone and Android devices. These tools draw on data from Monash research that has quantified the FODMAP content of different foods. The App and booklet provide accurate information about foods that may aggravate IBS symptoms, enabling sufferers to better manage their IBS symptoms. The App has been overwhelmingly successful having been downloaded in over 60 different countries and having reached number one in over 30 countries. In Australia, the App remains number one in the medical category for both android and iPhone.

Consistent with their translational research agenda, the team at Monash has launched the Monash University Low FODMAP Certification Program. The certification program aims to make it easier for consumers with medically diagnosed IBS to identify and select low FODMAP food choices. Membership of the certification program enables food manufacturers to have their brand specific product information (including product pictures and website links) included in the App, thus low FODMAP certified food products display a green light against their branding to clearly indicate to consumers that the food is low in FODMAPs. Some food manufacturers may also display the Monash University Low FODMAP Diet Stamp  on their food packaging, enabling consumers to quickly and easily identify low FODMAP food choices on the supermarket shelves.

The certification program seeks to promote the consumption of high quality, healthy foods, thus only foods which meet strict nutrient criteria for FODMAPs, fat, saturated fat, sugar, salt and fibre are eligible. Major categories of foods that are suitable for the certification program include: cereal grain products; legumes, nuts and seeds; fresh fruit and fruit products; fresh vegetables and vegetable products; milk, dairy products and alternatives, and quality convenience foods.

The certification program will be launched in October 2014. Should food manufacturers wish to learn more about this exciting new initiative, they should contact med-lowfodmap.certified@monash.edu

Low Carbohydrate High Fat Diets

The evolution of low carb
In recent times the low carbohydrate trend has evolved from a short term weight loss diet to being promoted as a long term “lifestyle”.

In line with this trend, the low carbohydrate high fat (LCHF) lifestyle has emerged as the latest diet philosophy being hailed in the media as the secret to long term weight loss, health and wellbeing. In fact, some LCHF proponents are now calling for all Australians to adopt a LCHF eating pattern, which represents a radically different diet to those recommended within evidenced based Australian and International Dietary Guidelines.

Here we explore the LCHF diet, review the evidence behind some of the recent headlines and discuss how a LCHF eating pattern stacks up against evidenced based guidelines which promote adequate nutrition and reduced risk of disease over the lifespan.  

What is a LCHF diet?
Due to the similarities with ‘Paleo style diets’ LCHF dieters often use the terms interchangeably or in concert when describing their diet philosophy.

The purpose of a LCHF diet is to achieve state of ‘ketosis’. This occurs when the body is starved of its primary fuel source (carbohydrates) and so is forced to use dietary fats as an alternative source of energy via ketosis.(7) Supporters of LCHF diets claim an eating pattern that imposes a metabolic shift towards ketosis reduces the risk of heart disease, diabetes and obesity as well as improves appetite control, weight management, immunity, sustained energy and mental alertness.(1-5)

As the name suggests, LCHF diets are characterised by very low carbohydrate intakes, generally less than 50g/day which is achieved through the elimination of selected foods from the five food groups including grain foods including whole grain or high fibre grain foods, legumes, fruit, low fat diary and starchy vegetables. (1-3) In addition, similar to the Australians Dietary Guidelines, LCHF dieters are instructed to limit or avoid discretionary choices such as sweetened beverages, cakes, biscuits, pastries and other carbohydrate containing discretionary food choices.

As a result LCHF diets contain relatively higher intakes of fat and protein through an abundance of dietary fats and oils, meats (often including processed meats such as bacon, sausages), seafood, eggs, nuts, seeds and full fat dairy. A typical LCHF daily meal plan recently published by advocates of LCHF diets delivers around 10,500kJ of energy,  42g carbohydrates (7% total energy), 20g fibre, 204g total fat (~72% total energy), 81g saturated fat (28% total energy), 78g monounsaturated fat and 28g polyunsaturated fat and 134g protein (~22% total energy).(3, 6)

To put this in context, the 2013 Australian Dietary Guidelines were developed using the NHMRC Nutrient Reference Values (NRV’s) for macronutrients. These NRV's are expressed as a percentage contribution of carbohydrate, protein and fat to daily energy intake (carbohydrate 45-60%: fat 20-35%: saturated fat no more than 10%: protein 15-20%). These NRVs provide the macronutrient ranges upon which the Australian Dietary Guidelines to ensure these recommendations allow a wide range of dietary patterns, which provide all of the essential nutrients and promote health.

Based on this analysis it’s clear that LCHF eating patterns are radically different to those endorsed by the Australian Dietary Guidelines and it follows that elimination of carbohydrate rich food groups also translates to lower intakes of the essential nutrients and health protective components these foods deliver. Indeed the example LCHF daily meal plan outlined above is lower in fibre than the adequate intake NRV and is significantly lower than the Suggested Dietary Targets (SDTs) for fibre recommended for reduced risk of chronic disease.

The latest science on LCHF
As with all science there is constantly new research being conducted leading to scientific debate. While it is important to consider the findings of new research, this must be done in the context of all the research in the area and not in isolation of single studies. As such systematic analysis of the total body of evidence is vital to guide the practise of health care professionals as is the critical analysis of new research to ensure that the findings are fair, unbiased and relevant in the real world.

With this in mind; in regards to weight management, while there is limited evidence that LCHF may offer short term benefits, robust scientific analysis including a recent meta-analysis consistently demonstrates that low carbohydrate or LCHF diet do not offer any long term weight loss benefits compared with an energy matched balanced diet.(7, 8)

A recently published trial which generated the headline in the New York Times “A Call for a Low-Carb Diet That Embraces Fat” clearly illustrates why critical analysis of new research is important. The study behind this headline was a 12 month trial of 148 obese people which compared a LCHF diet versus a higher carbohydrate diet and their respective effects on weight and heart health.(9) When interpreting studies which compare low carbohydrate diets versus a higher carbohydrate, it is important to keep in mind that not all carbohydrate foods are equal. As such it is important to examine the actual food choices and nutrient intakes of study participants to determine whether a low carbohydrate diet compared against a higher carbohydrate diet which actually reflects dietary guidelines, which emphasise nutrient and fibre rich carbohydrate foods.

This trial did not provide detail on the actual food choices of people on the higher carbohydrate diet, which was intended to reflect dietary guidelines. As many carbohydrate foods restricted on a LCHF diet are also fibre rich, it would be fair to assume the fibre intakes of the people on this diet would be significantly higher compared with a LCHF diet. However, in this study fibre intakes were almost identical and much lower than recommended intakes, with daily averages of 15g and 16g for the LCHF and higher carbohydrate diet respectively. This tells us that on average the higher carbohydrate group were not consuming fibre rich sources and so the group upon which the LCHF has been compared is unlikely reflective of a dietary guidelines. Given this analysis, it’s not surprising that those following the LCHF diet, which represented a radical change in diet, consumed less energy, losing more weight over 12 months and so experienced greater improvements in heart health when compared with a diet which did not reflect a healthy higher carbohydrate diet.

This limitation and others highlighted here by Dr David Katz, Director of the Yale Prevention Research Centre demonstrate the importance of the critical analysis of new research. As well as identifying critical flaws in the study design Dr Katz noted important factors for establishing a long term eating pattern which are commonly ignored in such studies including “Was the diet sustainable? Could families join in? Would the diet reliably improve health and prevent disease across a lifespan?”.

As Dr Katz points out, when it comes to achieving or maintaining a healthy weight the best approach is to establish an eating pattern and lifestyle which you can live with for a lifetime. In contrast a LCHF diet restricts many nutritious, affordable and culturally and socially acceptable foods and is yet to be proven to promote health in the long term.

In addition to research on weight management and heart health researchers have investigated the short term impact of LCHF diets on blood glucose control. In people with diabetes or an increased risk of diabetes a number of recent trials have reported positive outcomes of LCHF diets in the short term.(10, 11) Indeed, some researchers have cited such trials and challenged the current best practice guidelines for the treatment of diabetes in adults, making the case that low carbohydrate ketogenic diets as the primary dietary therapy.(12)

Despite this recent evidence, it should be noted that the evidence is limited and that the best practice guideline updated in 2013, provide recommendations based on the total body of evidence indicate that for improved blood glucose control for adults with diabetes as well as adequate nutrition and reduced risk of disease, macronutrient intakes should be individualised within the ranges which guide nutritionally balanced dietary guidelines.(13)

Potential long term risks of LCHF 
While there is some limited evidence of short term health effects of a LCHF diet, as a long term eating pattern LCHF diets are yet to be proven to provide adequate nutrition, be sustainable and prevent disease across the lifespan.

In contrast there is evidence that lower carbohydrate intakes in the long term may pose health risks. A 2013 meta-analysis found that compared with high carbohydrate intakes, long term low carbohydrate intakes  were linked with an increased risk of an early death in humans by 30%.(14) This observation has since been supported by a comprehensive study in animals; not possible in humans due to its complexity and for ethical reasons, which found that mice consuming a higher carbohydrate diet experienced a 30% increased life span and better health compared to mice consuming lower carbohydrate intake.(15)

LCHF diets may also negatively impact risk of heart health and type 2 diabetes through restriction of nutrient and fibre rich whole grains, high fibre grain foods and legumes.(16-23) And the abundance of saturated fat(3) observed in LCHF diets also contradicts recommendations from heart health authorities around the world who advise people to restrict intake of saturated fat in favour of polyunsaturated fat.(21, 24-26)

With respect to reducing cancer risk, LCHF diets do not align with key recommendations from the World Cancer Research Fund. LCHF diets appear to fall short of providing adequate fibre yet dietary fibre, particularly cereal fibre protects against bowel cancer, Australia’s second biggest cancer killer.(27, 28)The World Cancer Research Fund also cautions against high intakes processed meats which may be observed in a LCHF eating pattern due to the link between these foods  and some cancers.(27)

While the long term impact of a LCHF on disease and longevity is unknown, the 2013 Australian Dietary Guidelines are based on over 55,000 studies, demonstrates that an eating pattern relatively higher in good quality carbohydrate foods such as whole grains, high fibre grain foods, legumes, fruit and vegetables, moderate in protein and lower in saturated fats delivers adequate nutrition and reduces risk of diet related disease over the lifespan.(21)

The Bottom Line: Bring back the balance
Surveys indicate Australians are choosing discretionary grain foods more often than is recommended and are not choosing whole grain and high fibre grain foods often enough. Rather than following a fad diet, the total body of scientific evidence shows people would benefit from eating less discretionary foods and choosing whole grain and high fibre grain foods more often as part of a balanced diet.

In support of the evidenced based 2013 Australian Dietary Guidelines, GLNC encourages Australians to enjoy grain foods 3-4 times each day, choosing at least half as whole grain or high fibre and aiming to eat legumes at least 2-3 times each week.

References: 

1. Schofield G. THE SCIENCE OF HUMAN POTENTIAL 2014. Available from: http://profgrant.com/author/gschofie/.
2. Knoakes T. 2014. Available from: http://originaleating.org/.
3. Volek JS, Phinney SD. A New Look at Carbohydrate-Restricted Diets: Separating Fact From Fiction. Nutrition today. 2013;48(2):E1-E7 10.1097/NT.0b013e31828814eb.
4. Gunnars K. Available from: http://authoritynutrition.com/.
5. Evans P. Available from: http://www.thepaleoway.com/index.html.
6. FAO. CALCULATION OF THE ENERGY CONTENT OF FOODS - ENERGY CONVERSION FACTORS 2002. Available from: http://www.fao.org/docrep/006/y5022e/y5022e04.htm.
7. DAA. DAA Best Practice Guidelines for the Treatment of Overweight and Obesity in Adults. 2012.
8. Naude CE, Schoonees A, Senekal M, Young T, Garner P, Volmink J. Low Carbohydrate versus Isoenergetic Balanced Diets for Reducing Weight and Cardiovascular Risk: A Systematic Review and Meta-Analysis. PloS one. 2014;9(7):e100652.
9. Bazzano LA, Hu T, Reynolds K, Yao L, Bunol C, Liu Y, et al. Effects of Low-Carbohydrate and Low-Fat Diets: A Randomized TrialEffects of Low-Carbohydrate and Low-Fat Diets. Annals of internal medicine. 2014;161(5):309-18.
10. Tay J, Natalie D L-M, Thompson CH, Noakes M, Buckley JD, Wittert GA, et al. A Very Low Carbohydrate, Low Saturated Fat Diet for Type 2 Diabetes Management: A Randomized Trial. Diabetes care. 2014.
11. Schwingshackl L, Hoffmann G. Comparison of the long-term effects of high-fat v. low-fat diet consumption on cardiometabolic risk factors in subjects with abnormal glucose metabolism: a systematic review and meta-analysis. British Journal of Nutrition. 2014;111(12):2047-58.
12. Feinman RD, Pogozelski WK, Astrup A, Bernstein RK, Fine EJ, Westman EC, et al. Dietary Carbohydrate restriction as the first approach in diabetes management. Critical review and evidence base. Nutrition. 2014(0).
13. Dworatzek PD, Arcudi K, Gougeon R, Husein N, Sievenpiper JL, Williams SL. Nutrition Therapy -  Canadian Diabetes Association Clinical Practice Guidelines Expert Committee. Canadian Journal of Diabetes. 2013;37:S45-S55.
14. Noto H, Goto A, Tsujimoto T, Noda M. Low-Carbohydrate Diets and All-Cause Mortality: A Systematic Review and Meta-Analysis of Observational Studies. PloS one. 2013;8(1):e55030.
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