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Their role in weight management
The World Health Organisation recognises that healthy weight maintenance is a large challenge, as is overcoming obesity. Despite the public health significance of obesity and the promotion of various weight loss diets, there is no scientifically agreed optimal diet for its prevention and treatment, and opinions differ about the role of nutrients such as dietary fats and carbohydrates in the cause. Research does show, however, that diets including wholegrains and fibre can help to reduce the risk of being overweight.
Wholegrains
'Wholegrain’ foods contain intact and /or milled grains where the grain components - bran (fibre-rich outer layer), endosperm (middle starch and protein layer) and germ (nutrient rich inner core) - are present in the same proportion as in the original grain.
Wholegrains are important sources of carbohydrate, protein, dietary fibre, minerals, vitamins and other bioactive components such as antioxidants. The many benefits of wholegrains are well documented, in particular their association with protection against chronic diseases (heart disease, diabetes and some cancers). They have also been shown to have role in long term weight control.
There is good evidence from scientific studies that a diet high in wholegrains is associated with a lower body mass index (BMI), waist circumference and risk of being overweight.
A study of over 27,000 men showed high wholegrain intake to be inversely associated with long term weight gain. For every 40g of wholegrains eaten daily, weight gain was reduced by an average of 0.49kg.
Another study found a higher intake of wholegrain or high fibre foods to be associated with a 49% lower risk of becoming obese over a 12 year period. Plant based foods and dietary fibre were shown to be protective against excess bodyweight in a large, ethnically diverse research population.
The higher fibre content of diets rich in wholegrains is believed to be one of the means by which they help control body weight. Research shows that increased dietary fibre promotes satiety due to its bulk and low energy density, with hormonal responses leading to reduced hunger and reduced energy intake. The high-fibre content of most wholegrain foods is believed to help in preventing weight gain by increasing appetite control. It does this by delaying carbohydrate absorption, hence promoting the feeling of fullness.
Increasing dietary fibre intake by an additional 14g per day has been shown to result in a 10% decrease in energy intake and a weight loss of over 1.9 kg over 4 months. The effects of dietary fibre were more striking in obese individuals. The authors of this US study concluded that increasing dietary fibre intake from the current average of 15g to 25-30g per day, would be beneficial and may help reduce the prevalence of obesity.
In addition to fibre there are also additional components in wholegrains that contribute to metabolic changes, favouring long term weight management.
The National Health and Medical Research Council recommend a dietary fibre intake of 25-30g per day for adults and 14-18g per day for children above one year of age.
There is currently no official recommendation for wholegrain intake in Australia, but based on the scientific evidence, Go Grains Health & Nutrition recommends 48g of wholegrains a day is an achievable, evidence based target intake.
Wholegrain content of some foods
Sources:
Williams P et al., Cereal grains, legumes, and weight management: a comprehensive review of the scientific evidence. Nutr Rev. 2008 Apr;66(4):171-82.
Koh-Banerjee P et al., Changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men. Am J Clin Nutr 2004;80:1237-45.
Liu et al., relation between changes in intakes of dietary fiber and grain products and changes in weight and development of obesity among middle-aged women. Am J Clin Nutr. 2003. 78:920-7.
Slavin J and Green H. Dietary Fibre and Satiety. British Nutrition Foundation Nutrition Bulletin. 2007. 32(suppl 1). 32-42.
Griffiths T. Towards and Australian ‘daily target intake’ for wholegrains. Food Aust 2007. 59(12):600-601.
Harlan J and Garton LE. Whole-grain intake as a marker of healthy body weight and adiposity. Public Health Nutrition: 11(6), 554-563.
NHMRC. Nutrient Reference Values for Australia and New Zealand. Executive Summary. 2006.
Your daily dose for disease prevention?
When it comes to grain foods, wholegrains are shining stars. Wholegrain foods and legumes are a fundamental part of a balanced diet and scientific studies consistently show that they can play a major role in reducing the risk of many of the chronic diseases that burden our society today. Wholegrains may even be more important than first thought, with new research collected as part of "The Grains & Legumes Health Report - A Review of the Science" finding that wholegrain foods could help prevent asthma and gum disease, and may also improve mood and cognitive function.
The Grains & Legumes Health Report is a review of the latest scientific evidence on the health benefits of grains and legumes, co-authored by Associate Professor Peter Williams, University of Wollongong and Go Grains Health & Nutrition, with the report's foreword written by Chief Research Scientist, CSIRO Food Futures National Research Flagship, Dr David Topping.
Wholegrains contain all the goodness of the grain – however, it’s the fibre-rich outer bran layer and nutrient-rich inner core (germ) that makes them so special. They contain plenty of vitamins (particularly B-group vitamins and vitamin E), minerals (notably iron, zinc, magnesium and phosphorus), fibre and protective substances (like antioxidants and phytonutrients). The most commonly eaten wholegrain foods include wholemeal and mixed grain breads and crispbreads, oats, wholemeal pasta, brown rice and pop corn. Wholegrain foods can contain grains that are whole (visible grains), or milled into finer pieces (wholemeal). Therefore, wholemeal foods are also wholegrain.
Eating the equivalent of 2-3 slices of wholegrain bread a day (or 1½ cups of wholegrain breakfast cereal, brown rice or wholemeal pasta) can reduce the risk of developing cardiovascular disease, type 2 diabetes, certain cancers and obesity by up to 20-30%. Wholegrain foods may even be as powerful as cholesterol lowering medication, with 2-4 serves of wholegrain foods a day lowering the risk of heart disease by as much as 40% - equal to the effect of statin drugs.
Research studies show a diet high in wholegrain foods can help to lower blood pressure. One particular study found that replacing white rice with brown rice, white bread with wholegrain, and low-fibre cereals with barley or whole wheat cereals, significantly reduced blood pressure in overweight patients with high cholesterol in just 5 weeks.
For those at risk, but who have not yet developed type 2 diabetes, wholegrains may be the solution. Research has shown the progression of impaired glucose tolerance to type 2 diabetes can be reduced by almost 60% and insulin resistance improved, by simple lifestyle changes such as frequently eating wholegrain foods.
In addition to the more established benefits of wholegrains in the prevention of chronic disease, there is also emerging science about the benefits of wholegrain consumption for prevention of periodontal disease and asthma, as well as suggestive evidence for improvements in mood and cognitive function. Further research will help confirm these promising findings.
What is it about wholegrains that makes them so impressive? The complete package of fibre, vitamins, minerals, antioxidants and phytonutrients work together – research suggests there is no one single component in wholegrains which accounts for their beneficial effect to health.
There is very little research data available on wholegrain consumption in Australia but we understand adults and children are not eating enough. A recent survey conducted by Go Grains Health & Nutrition found that on average Australians aged 5 – 70+ are eating less than 1½ serves of wholegrain foods a day, falling short of international recommendations that at least half of all grain consumption should be wholegrain. Children should increase the amount of wholegrains in their diets as they grow.
Legumes are an economical, easy to prepare and nutritious food that Australian’s are not eating enough of. Research shows that less than a quarter of Australians eat legumes every day while data from the latest National Children’s Nutrition and Physical Activity Survey in 2007 revealed only 5-7% of Australian children aged 2-16 years are eating legumes each day.
Legumes provide a range of essential nutrients including good quality protein, low glycaemic carbohydrate, vitamins, minerals and dietary fibre. They are generally low in fat and contain no cholesterol. Among the well known legumes are navy beans (baked beans), chickpeas, soybeans, lentils, red kidney beans, cannellini beans, butter beans and split peas.
Epidemiological studies consistently show that eating legumes can help reduce the risk of cardiovascular disease, type 2 diabetes and obesity, as well as improve gut health. One study found that consumption of legumes four or more times per week, was associated with a 22% lower risk of coronary heart disease and 11% lower risk of cardiovascular disease.
A seven year longitudinal study of older people from different dietary cultures (including Japan, Sweden, Greece and Australia), found higher legume intake was the most protective dietary predictor of longevity, with a 7-8% reduction in risk of death for every 20g increase in daily legume intake.
Recent science suggests there may be a stronger role for legumes in helping to protect against prostate, breast and colorectal cancer than previously thought. Two large international cohort studies report; a lower incidence of colorectal adenoma’s in women who consumed four or more servings of legumes a week, and a 33% lower risk of colorectal cancer in women who ate the most legumes, although much of the evidence is limited to soy intake as there are generally low intakes of other legumes in most free-living populations.
There is consistent scientific evidence for the role of wholegrains, and suggestive evidence for the role of legumes, in protecting against cardiovascular disease, type 2 diabetes, certain cancers and obesity. The risk reduction (20-30%) from just three serves of wholegrain foods (equivalent to 3 slices of wholegrain bread) a day could theoretically translate to health expenditure savings of over $1.2 billion a year.
Start by switching to a wholemeal / mixed grain bread or wholegrain breakfast cereal.
To download a copy of The Grains & Legumes Health Report, visit www.gograins.com.au
Refined carbohydrates - better than you think!
Mixed messages about carbohydrates and their effect on the body are common in the media, with research findings sometimes contributing to further confusion. Carbohydrate foods such as bread and rice have been staples from ancient times for many cultures, but today there are many misconceptions about how and when they should be eaten or even if they should be eliminated from the diet. Avoid eating carbohydrates after a certain time of the day as you won’t burn them off or opt for low glycaemic index (GI) carbohydrate choices - does this sound familiar, the dos and don’ts of eating? Carbohydrates are often linked to causes of obesity and other chronic illnesses, but are other underlying factors responsible?
Carbohydrates are an important source of energy for the body, particularly the brain, nervous system and red blood cells. They are found in many foods we eat in different forms ranging from those closest to their natural form (oats, rice, legumes), to those that have been processed to allow eating and digesting more readily (bread, pasta, breakfast cereals), to those that are considered more a ‘treat’ (sugars, sweet biscuits, soft drinks).
Carbohydrates should contribute approximately 45-65 percent of the energy in a healthy diet. Healthy carbohydrate options include grain-based foods like bread, breakfast cereals, rice, pasta, noodles and legumes, starchy vegetables, fruit and milk products. Cutting out these carbohydrate foods does not make good sense as they contribute important nutrients including protein, dietary fibre and essential vitamins and minerals such as iron, folate and thiamin. Wholegrain varieties also contain many components that can promote good health.
‘Not so healthy’ carbohydrate foods such as soft drinks, cordials, fruit juices, lollies, cakes, doughnuts, sweet biscuits and pizza add few if any nutrients to the diet and may be inappropriate sources of energy on a regular basis.
Carbohydrates and health
Carbohydrates have differing effects on blood glucose levels depending on the type and quantity eaten. The carbohydrates in foods with a high glycaemic index (GI) are digested rapidly whereas those in low GI foods are slowly digested. A low GI diet is generally encouraged but a healthy diet can include both high and low GI foods.
A small number research studies have shown an association between a high GI diet and increased risk of disease such as heart disease. On closer inspection the carbohydrate food sources in such studies are not always representative of healthy options but often include less healthy options such as sugar, honey, jam, pizza and cakes. These foods are often higher in saturated fat, with up to double the amount recommended by health authorities which could also attribute to health outcomes. Other factors which may influence study outcomes, but are not always accounted for, include body weight, smoking, exercise, alcohol consumption and stress management.
When considering the pros and cons of eating carbohydrates, nutrient content should be considered as well as the GI. Carbohydrates foods such as breads, cereals, rice, pasta and oats provide a range of important nutrients. Refined varieties are lower in nutrients than wholegrain varieties but can make a nutritionally important contribution to a healthy diet. Carbohydrate foods such as soft drinks, confectionary, cakes and sweet biscuits provide minimal nutrients and are not a suitable part of a healthy diet on a regular basis.
Australian dietary guidelines recommend 4+ serves a day of grain-based foods such as breads, breakfast cereals, rice, pasta and crispbreads, and it is good practice to make at least half of these wholegrain. Variety is important, so choose from all food groups daily, with less healthy ‘treats’ eaten only occasionally.
Popular 'low carb' diet overhauled
Fad diets come and go and some are revisited, but yet they always seem to be an ongoing topic of conversation in the media and even amongst friends. The Atkins diet is back and revamped with the inclusion of fruit and vegetables. Wholegrains are introduced in the maintenance phase. Why has this diet been changed if it was, in its original form, an appropriate and successful method for weight loss? Can it be that event the proponents realise there is a better way?
The word 'diet' is a head turning top, but for most dietitians and nutrition healthcare professionals, it can have an eye rolling effect. The term 'diet' - once used to describe the usual food and drink intake of a person - is now more commonly associated with a restrictive regimen to promote weight loss.
There are countless diets that claim effective and quick weight loss, most often not supported by research. Weight loss trademarks claiming 'sweet, sexy, science' are related more to marketing than to credible research. What can be sweet and sexy about a weight loss program even though it claims to have the science behind it? Science in simple terms is knowledge gained through research and investigation.
Our ancestors seemed to live a simple life, food was consumed closest to its natural form, technology was not as evolved, people were more active and overweight and obesity was not common. Today the incidence of overweight and obesity is of concern. In 2007-08, one quarter of all Australian children aged 15-17 years were overweight or obese. Studies have shown that once children become obese they are more likely to stay obese into adulthood and have an increased risk of developing chronic diseases. In 2007-08, almost two-fifths (37%) of adults in Australia aged 18 years or over, were overweight and a further quarter (25%) were obese. The economic cost of obesity due to the loss of wellbeing and burden of disease is enormous ($8.3 billion in 2008, in Australia).
The World Health Organisation projects that by 2015, approximately 2.3 billion adults will be overweight and more than 700 million will be obese, globally. With these fast growing statistics it is no wonder that organisation are claiming to have the solution to weight problems.
The simple laws of physics demand that energy 'in' should equal energy 'out'. However, our increasingly sedentary lifestyle at work and home, modes of transportation and increased intakes of energy dense foods (high in fat and sugar but low in vitamin, minerals and other nutrients), means the modern trend is for a higher energy intake than expended by the body.
Surely a lifestyle change is necessary to ensure energy consumed does not exceed expended, rather than a diet that claims to kick start weight loss by restricting carbohydrates? Even the term 'kick start' mentions physical activity! As well as monitoring food intake, physical activity should be a focus of healthy weight management.
Diets that are focused on restricting carbohydrates (commonly referred to as carbs) - some even go to the extent of providing carb counters - should send off warning bells. Who wants to count numbers around everything eaten? Weight management is not simply about limiting energy by restricting carbohydrate intake - because everything contributes energy, particularly fat and protein - but more about quality and quantity eaten.
Diets that severely restrict carbohydrates often recommend eating meat such as bacon on a regular basis and clearly do not have the correct science behind them. For example, a piece of bacon is nutritionally inferior to a slice of wholegrain bread or an apple - high quality carbohydrate foods that provide nutrients, antioxidants and fibre. What is important is the quality of carbohydrate eaten. Fruit, breads, cereals (particularly wholegrain) and legumes are carbohydrate containing foods that should be included in a healthy diet every day, whereas carbohydrate foods such as ice cream, soft drinks and sweet biscuits should be treated as 'occasional' foods.
Food is not only eaten to provide sustenance, it also provides enjoyment, and often brings family and friends together. So too does exercise (gold, soccer, football, walking). Remembering the simple rule of physics ensures we can enjoy eating a variety of food and drink in moderation each day, whilst being physically active. Maintaining this long term contributes to a healthy lifestyle.
Sources:
1. http://www.atkins.com/
2. Australian Bureau of Statistics, 2009. Australian Social Trends. Commonwealth of Australia
3. World Health Organisation, 2006. Fact Sheet 311: Obesity and overweight
Switch your sports drink for cereal & milk
You have just returned home from a long bike ride or run, do you reach for the big brand sports drink or sit down to a nutritious bowl of wholegrain cereal and milk? The results from a recent study in the US could change your mind and improve your bank balance. The researchers found the readily available and cost effective recovery option of cereal and low fat milk was comparable to sports drinks in refuelling muscles with glycogen, and may be better at helping tired muscles build protein.
Originally designed to offset dehydration in elite athletes, sports drinks are marketed strongly and have high product awareness amongst the general public and elite athletes. They contain sodium, potassium and chloride plus around 6% carbohydrates and are formulated to aid rapid recovery by providing energy for active muscles and electrolytes for re-hydration. Available in an endless range of flavours to suit individual preferences, sports drinks may help to encourage drinking and re-hydration through their preferred taste compared to water.
Lynne Kammer and her team of researchers at the University of Texas at Austin set out to research the effect of using ordinary foods after moderate exercise (as performed by an average fit individual) to support recovery processes. Endurance exercising causes short term changes to occur in the body, particularly in the muscle. Energy stores are depleted and muscle proteins are broken down to make way for new, stronger muscle proteins. Optimal recovery of muscle energy stores and muscle repair requires eating the right foods at the right times.
The researchers fed 12 healthy trained subjects with either 1200mL of sports drink or 73g (about 1 1/3 cups) of wholegrain cereal and 350mL of skim milk after 2 hours of moderate cycling (60-65% VO2Max). They found no significant differences between sports drink and cereal and milk, except for one marker of protein synthesis. The results of this study suggest that wholegrain cereal and milk is as good, and in some aspects may be better than, commercially available sports drink at kick starting muscle recovery after exercise, especially when refuelling at home, where cereal and milk is often freely available.
The important take home message from this study is not only that ordinary whole food sources such as cereal and milk may offer a more cost effective recovery strategy than commercial sports nutrition products, but also that the combination of protein and carbohydrate from whole foods provide an easily digestible, high quality source of protein and carbohydrates with naturally occurring nutrients, as compared to extra calories provided from a somewhat expensive sports drink. Other protein-carbohydrate recovery foods might include low-fat yoghurt and fruit, low-fat flavoured milk/smoothie or a sandwich with meat/cheese.
Sources:
Kammer et al, Cereal and nonfat milk support muscle recovery following exercise. J Int Soc Sports Nutr, 2009, 6:11
Keep regular and feel fuller for longer
Chronic constipation affects up to 27% of the population in Western countries and may affect an individual's quality of life. Research has shown that eating wholegrain rye bread relieves constipation and also decreases appetite.
Rye bread can help keep you regular
Nearly one half of those suffering from constipation are unsatisfied with their treatment due to it being ineffective. Various products are available in the market to alleviate constipation - ranging from natural to medicinal sources - but these can be costly and may result in unfavourable gastrointestinal effects (cramps, bloating, flatulence or diarrhoea).
A recent study has shown that an average of 2-3 slices* of wholegrain rye bread relieved mild constipation within one week without increasing unfavourable gastrointestinal effects. Wholegrain rye bread was more effective than wheat bread or laxatives, and improved bowel function compared to other forms of fibre or laxatives. It also created a favourable bowel environment, regulating gastrointestinal activity. Previous investigations have also shown that rye bread had positive effects on bowel function in healthy and constipated adults.
Rye is rich in dietary fibre and contains components such as arabinoxylan which appear to feed the growth of beneficial bacteria in the bowel. The growth of beneficial bacteria discourages the growth of harmful bacteria and contributes to intestinal health.
Rye bread can help keep you fuller
Other research has shown that eating wholegrain rye bread approximately 3-4 slices* resulted in decreased appetite compared to white wheat bread. Wholegrain rye bread decreased hunger feelings both before and after lunch when included in a breakfast meal, and rye bread and rye products resulted in a better insulin response. What contributed to the feeling of fullness is not known, however research to date has shown that foods naturally rich in dietary fibre promote this feeling and decrease appetite in the short term. Dietary fibre that delays absorption of nutrients may lead to the feeling of fullness for longer by increasing the time required for digestion.
Long term studies show that an increased intake of dietary fibre results in a lowered energy intake and loss of body weight. These results are also supported by studies that show a diet low in dietary fibre is associated with an increased risk of obesity.
About rye
Dating back as far as 500AD, rye was introduced as a staple in Britain by the Saxons and Danes. Today rye bread is made with various percentages of rye flour and is generally available in 3 varieties:
- light rye - a combination of rye and wheat flour (lighter, softer, milder flavoured bread)
- dark rye - includes a large proportion of rye flour
- pumpernickel - dark bread made from a mixture of rye flour, rye meal and kibbled or cracked rye grains
Rye bread can be light or dark in colour depending on the proportion of rye flour used. It is often dense in texture and high in fibre. Look out for words "whole", "wholegrain", kibbled" and "flaked" next to rye in the ingredients list. Remember ingredients are listed from highest to lowest quantity in the product.
*1 slice = 35g
Sources:
1. Holma et al. Constipation is relieved more by rye bread than wheat bread or laxatives without increased adverse gastrointestinal effects. J.Nutr. 2010; 140: 534-541
2. Isaksson et al. Effect of rye bread breakfasts on subjective hunger and satiety: a randomized controlled trial. Nutrition Journal. 2009; 8:39
3. Rosen et al. Endosperm and whole grain rye breads are characterized by low post-prandial insulin response and a beneficial blood glucose profile. Nutrition Journal. 2009; 8:42
Beyond cholesterol lowering
Don't wait for a cold winter's day to reap the health benefits of oats. New evidence suggests there may be more to oats than cholesterol lowering, with recent research revealing special compounds in oats may help protect against heart attached by reducing inflammation and blockages in blood vessels, and initial investigations have found oats may decrease the risk of asthma in young children.
Killing one Australian every 10 mins and affecting two out of three Australian families, cardiovascular disease (CVD) is the leading cause of death in Australia with huge financial impacts on our health care system. Fortunately, many of the risk factors for CVD are preventable including smoking, high blood pressure, lack of physical activity, diabetes, overweight, obesity and high cholesterol.
For the past decade or more, there have been a growing number of scientific studies supporting the role that oats can play lowering cholesterol and helping to protect against cardiovascular disease. A new study has found oats can help not only reduce LDL (bad cholesterol), but also decrease waist circumference in overweight and obese adults as part of a 3 month weight loss program. Just 2 serves (40g each) of a wholegrain oat cereal each day as part of a weight loss program reduced LDL cholesterol by almost 10%, significantly more than lower fibre control foods as part of a weight loss program (5%). The even better news is; these favourable outcomes were noticed as early as 4 weeks into the study. Both groups lost around 2kg over the duration of the weight loss program, but the group eating oats lost significantly more weight from around their waist.
Oats are naturally rich in beta-glucan (a type of soluble fibre), considered to be responsible for the cholesterol lowering benefits of oats. More recently, another powerful component of oats has been linked to good health. Avenanthramides, a type of antioxidant has been found to help reduce the ability of blood cells to stick to artery walls. This effect could help reduce hardening of the arteries (atherosclerosis) which can in time lead to heart attack. One study also suggested these avenanthramides could help explain how oats can reduce the risk of colon cancer.
In addition to heart health, some evidence from initial investigations has shown oats can help reduce the risk of asthma in young children. The study conducted in Finland found early introduction (in the first 6 months) of oats into the diets of babies with an increased risk for type 1 diabetes was associated with a significantly lower risk of persistent asthma by the age of 5 years. These findings need to be confirmed in other populations.
Oats are an economical and versatile wholegrain that can provide the whole family with essential vitamins, minerals, and fibre for good health. Many food manufacturers have realised the health benefits of oats, and you can now enjoy the pleasure of eating oats all year round with new product developments such as oat breakfast biscuits, bread with added oats and many flaked and shaped breakfast cereals made from oats. Aim to eat 4 or more serves of grain-based foods (like oats, breads, breakfast cereals, pasta and rice) everyday - at least half should be wholegrain.
Sources:
1. Maki KC et al. Whole-grain ready-to-eat oat cereal, as part of a dietary program for weight loss, reduced low-density lipoprotein cholesterol in adults with overweight and obesity more than a dietary program including low-fibre control foods. J Am Diet Assoc. 2010; 110;205-214
2. Andon MB et al. Stae of the Art Reviews: The oatmeal-cholesterol connection: 10 years later. AJLM 2008; 2:51-57
3. Virtanen et al. Early introduction of oats associated with decreased risk of persistent asthma and early introduction of fish with decreased risk of allergic rhinitis. B J Nutr. 2010; 103:266-273
