Watch your weight with legumes (and quality carbs)

With winter approaching it may be tempting to curl up on the couch and give yourself permission to relax your healthy routine. But sadly, evidence shows that weight gained during short periods of over-indulging and reduced exercise like the “winter weight creep” can hang around for months and years to come, making it harder to lose weight and stay trim long term.⁽¹⁾ The evidence continues to support a focus on carbohydrate “quality” rather than “quantity” for a healthy weight, which is why enjoying legumes more often can make big changes to your waistline now and in years to come.   

Shifting the focus to carbohydrate quality

While there is no shortage of fad diets or unsubstantiated advice advocating the restriction of all carbohydrate foods, the scientific evidence consistently shows that the quantity and proportion of carbohydrate in the diet does not predict long-term changes in weight.^{(2, 3)} A key pitfall of such advice is that it does not discriminate between nutrient-rich carbohydrate foods (like legumes, grain foods, starchy vegetables, milk and yoghurt) and nutrient-poor discretionary choices linked with poor health and weight gain (such as sweetened beverages, cakes, biscuits, pasties and confectionary). In addressing the misunderstanding and miscommunication of the relationship between carbohydrates and health, nutrition researchers are increasingly investigating the effect of carbohydrate quality within the diet for reducing risk of weight gain and promoting health over the life span.

To assess carbohydrate quality of an overall diet or specific foods, a number of criteria have been suggested including dietary fibre content, whole grain content, whether the carbohydrate is in a solid or liquid form and the glycemic index (GI).^(4-6) In line with this emerging area of research a recent study, the first study of its kind measured the “carbohydrate quality index” (CQI) (the sum of each of the criteria outlined above up) of young Spanish adults diets and investigated the long-term effect on weight.

In this Mediterranean cohort, a higher CQI was linked with higher intakes of legumes, fruits, vegetables, whole grains, fish and olive oil as well as higher intakes of total carbohydrate, fibre, protein and omega-3 fatty acid. After an average of eight years, the researchers found that people with the highest CQI had the lowest weight gain over time and a 26% lower risk of overweight or obesity, compared to those with the lowest CQI.

This study provides further evidence that making smart carbohydrate food choices (rather than focusing on quantity) is important for promoting a healthy weight, and adds to evidence that higher consumption of legumes is linked with smaller waist circumferences and a lower risk of weight gain.⁽⁷⁾ Considering that legumes tick all the boxes for being good quality carbohydrate foods – being fibre and nutrient rich whole foods which are also mostly low GI – they offer one way for many Australians to improve the overall carbohydrate quality of their diet and reduce weight gain over time.

Weight loss with legumes

As well as reducing risk of weight gain in the long term, choosing legumes and other good quality carbohydrate foods over poor quality carbohydrate foods is an important consideration for people aiming to lose weight. Choosing good quality carbohydrate foods helps people to meet their nutrient needs with less energy intake as well as enhances satiety (fullness after a meal) each of which promote weight loss.

A recent meta-analysis of studies, which provides the highest quality of evidence available, found that legumes had a 31% greater effect on satiety (feeling of fullness after a meal) compared with a control, which was generally white bread.⁽⁸⁾ This finding helps to explain the findings of a previous review of short-term weight loss studies, which found that the inclusion of legumes within an energy restricted diet resulted in significantly greater weight loss compared to energy matched diets without legumes.⁽⁹⁾

Start a healthy habit with legumes

With over two-thirds of Australians currently overweight or obese, and over on- third of Australians daily energy intake coming from energy-dense, nutrient-poor choices, improving the overall quality of carbohydrate food choices should be a high priority for Australians. For many, a simple first step to improve carbohydrate quality and promote a healthy weight is to aim to enjoy legumes at least 2-3 times each week. This healthy habit is easier than you may think. These tips, tricks and meal ideas will assist people to enjoy legumes more often: Legumes – Start a healthy habit and An Everyday Guide to Cooking with Legumes.

References:

1.            Ernersson A, Nystrom F, Lindstrom T. Long-term increase of fat mass after a four week intervention with fast food based hyper-alimentation and limitation of physical activity. Nutrition & metabolism. 2010;7(1):68.

2.            Fogelholm M, Anderssen S, Gunnarsdottir I, Lahti-Koski M. Dietary macronutrients and food consumption as determinants of long-term weight change in adult populations: a systematic literature review. Food & nutrition research. 2012;56.

3.            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.

4.            DiMeglio DP, Mattes RD. Liquid versus solid carbohydrate: effects on food intake and body weight. Int J Obes Relat Metab Disord. 2000;24(6):794-800.

5.            Overby NC, Sonestedt E, Laaksonen DE, Birgisdottir BE. Dietary fiber and the glycemic index: a background paper for the Nordic Nutrition Recommendations 2012. Food & nutrition research. 2013;57.

6.            Shrapnel B, Noakes M. Discriminating between carbohydrate-rich foods: A model based on nutrient density and glycaemic index. Nutrition & Dietetics. 2012;69(2):152-8.

7.            Papanikolaou Y, Fulgoni VL. Bean Consumption Is Associated with Greater Nutrient Intake, Reduced Systolic Blood Pressure, Lower Body Weight, and a Smaller Waist Circumference in Adults: Results from the National Health and Nutrition Examination Survey 1999-2002. Journal of the American College of Nutrition. 2008;27(5):569-76.

8.            Li SS, Kendall CW, de Souza RJ, Jayalath VH, Cozma AI, Ha V, et al. Dietary pulses, satiety and food intake: A systematic review and meta-analysis of acute feeding trials. Obesity. 2014;22(8):1773-80.

9.            McCrory MA, Hamaker BR, Lovejoy JC, Eichelsdoerfer PE. Pulse Consumption, Satiety, and Weight Management. Advances in Nutrition: An International Review Journal. 2010;1(1):17-30.

Keep your immune health on track with legumes

To help keep our immune system on track this winter, many of us would benefit from taking a closer look at our lunch box or dinner plate before reaching for the medicine cabinet or the supplement isle. The science is clear that poor diet is a major cause of an impaired immune system, increasing a person’s risk of infection and decreasing the ability of the body to fight infections.^{(1, 2)} Here’s the evidence on the role of diet and immunity and why legumes may be the missing weapon in your arsenal fighting against infection this winter.

Immune responses are fuelled by diet

The immune system is a complex system that protects against infection. While this system is functioning at all times, the presence of a virus or harmful bacteria increases the activity of the system in order to mount an immune response. During such times, the immune system places an increased demand on the body and it is ultimately our diet that must supply the proteins, fats, vitamins and minerals that the immune system requires  to respond optimally to ward off or fight infection.^{(2, 3)}

As we enter the winter months, sustaining a nutrient-rich diet is an important step towards building a strong immune system and guarding against common infections like colds and the flu. For many Australians, the first step towards achieving a nutrient-rich balanced diet is to enjoy a wider variety of plant foods, particularly vegetables and legumes, instead of nutrient-poor discretionary foods (like cakes, biscuits, chips, sweetened beverages). The most recent National Nutrition Survey found that over one-third (35.4%) of Australians’ energy intake came from discretionary choices, while only 6.8% of Australians reporting meeting the recommended 5 daily serves of vegetables and only 4.5% of people ate legumes (also classified as a vegetable) on the day of the survey^{(4, 5)}. Enjoying a wider variety of plant foods, particularly vegetables and legumes more often will help to ensure a constant supply of the components essential for a healthy immune system including vitamin A, D, E, and B vitamins, zinc, iron, iodine and selenium^{(2, 3)}.

Boosting immunity with legumes  

As well as delivering essential nutrition, our diet also impacts on the balance of bacteria in our digestive system which plays an important role in our health and immune function. One way to improve the balance of bacteria in the gut is by providing a top of up of live beneficial bacteria, known as ‘probiotics’, which can be found in in fermented foods including cultured dairy products, some fermented milks and capsules. Probiotics have been found to support the immune system in a number of ways, including by helping to create a physical barrier that protects against infection and also by producing a range a compounds that can act directly to inhibit infection.⁽²⁾

While probiotics have received lots of attention, there is now emerging evidence that ‘prebiotics’ have the potential to induce the same or even enhanced immune effects, acting through similar mechanisms to probiotics.^{(2, 6-9)} Prebiotics are special types of dietary fibres that ferment in the digestive system and are abundant in legumes (such as peas, chickpeas, lentils and beans), as well as whole grain and high-fibre grain foods containing wheat, rye, barley, oats, brown rice and certain fruits and vegetables.^{(6, 10)} It is this fermentation that helps to feed the beneficial bacteria in the digestive system, improving the composition and/or activity of probiotics (already in the digestive system or consumed) which produce protective components and confer health benefits.⁽⁹⁾ Enjoying a range prebiotic-containing foods within a balanced diet may help to support the balance of bacteria and potentially improve immune function.^{(2, 9)}

The bottom line

Whole diets feed our immune system to fight and avoid common infections like cold and flu. The Australians Dietary Guidelines provide recommendations for Australians to meet nutrient requirement of macronutrients and micronutrients that are essential for immune function and resistance to infection.⁽¹⁰⁾ Legumes are one nutrient-rich plant foods with lots of potential to bring balance back to Australian diets that may also enhance immune health through the delivery of essential nutrition and a prebiotic effect – an increase in the balance of beneficial bacteria in the digestive system provides a range of health benefits including improved immune responses. 

References

1.            Katona P, Katona-Apte J. The Interaction between Nutrition and Infection. Clinical Infectious Diseases. 2008;46(10):1582-8.

2.            Calder PC. Feeding the immune system. Proceedings of the Nutrition Society. 2013;72(03):299-309.

3.            Calder PC. The Importance of Nutrition to Healthy Immune Function. Wellmune; 2013.

4.            ABS. Australian Health Survey: Nutrition First Results - Foods and Nutrients, 2011-12. Australian Bureau of Statistics, 2014.

5.            GLNC. Secondary Analysis of the National Nutrition and Physical Activity Survey 2011-2012 Unpublished: 2014.

6.            Muir J. Conference Presentation: What are the risks/benefits of fermentable carbohydrates? The FODMAP story. [4/4/13]. Available from: http://www.glnc.org.au/4th/events/ilsi-presentations/

7.            Lomax AR, Calder PC. Prebiotics, immune function, infection and inflammation: a review of the evidence. The British journal of nutrition. 2009;101(5):633-58.

8.            Bird AR, Conlon MA, Christophersen CT, Topping DL. Resistant starch, large bowel fermentation and a broader perspective of prebiotics and probiotics. Beneficial microbes. 2010;1(4):423-31.

9.            Gibson GR, Probert HM, Loo JV, Rastall RA, Roberfroid MB. Dietary modulation of the human colonic microbiota: updating the concept of prebiotics. Nutrition research reviews. 2004;17(2):259-75.

10.          NHMRC. Australian Dietary Guidelines: Providing the scientific evidence for healthier Australian diets 2013 [cited 2015 January]. Available from: http://www.nhmrc.gov.au/guidelines-publications/n55.

Legumes - The Forgotten Weapons of Risk Reduction

While life expectancies have never been higher so too are rates of chronic diseases, resulting in large number of people living for many years with disease. Type 2 diabetes, heart disease and cancers are so common today that many may think these are inevitable. This could not be further from the truth. There is a multitude of dietary and lifestyle choices or “weapons of risk reduction” which individuals can adopt to add years to life and life to years. Legumes, an often forgotten food group, have huge potential as a weapon of risk reduction to fight off disease in the long term.

Lessons from the longest lived

In recent decades researchers have studied the longest lived communities around the world where a fraction of people suffer the diet and lifestyle related diseases which plaque many countries today. These unique regions around the world, known as “Blue Zones”, provide an insight into potential guidelines to achieve and maintain health as well as happiness over the lifespan. ⁽¹⁾   

“Blue Zones” include the Mediterranean regions of Sardinia in Italy and Icaria in Greece, as well as the islands of Okinawa, Japan; Loma Linda, California and the Nicoya Peninsula in Costa Rica. From studying these populations, researchers have identified universal themes fundamental to health and happiness. When it comes to diet, an overriding theme from these Blue Zones is an emphasis on legumes, such as beans, chickpeas, lentils and peas within a mostly plant-based diet.

When it comes to legumes, the traditional Sardinian diet is particularly high in fava beans, the Icarian’s enjoy a diet rich in chickpeas, kidney beans and lentils, the Okinawan people and seventh day Adventists of Loma Linda have high intakes of soy from beans, tofu and soy milk, whereas the people of the Nicoya Peninsula, Costa Rica eat a variety of beans with rice as a staple in their diet.   

This is not to say that legumes are the only foods contributing to health in these diets, which are also rich in fruits, vegetables, nuts and whole grains. However, the prominence of legumes in these populations is worthy of remark as legumes are a largely forgotten food group in Australia, with only 7% of us reporting to eat them in the latest National Nutrition Survey.⁽²⁾ 

In addition to learnings from the Blue Zones, the scientific evidence from populations all around the world (not just Blue Zones) consistently demonstrates that people who eat higher intake of legumes have better health outcomes including a significantly reduced risk of heart disease, some cancers, and improved blood glucose control.⁽⁴⁾

The potential of legumes

The benefits of diets that emphasise legumes are not surprising given their nutrient density – in fact in a recent analysis of the Australian Health Survey, people who ate legumes had higher total daily intakes of fibre (30.4 g vs 21.9g), protein, iron, magnesium, zinc, iodine and folate compared with non-consumers.(5) In addition to essential nutrients, legumes are also rich in protective phytonutrients which are likely to also contribute to the associated health benefits observed in long term consumers.

When it comes to Australian diets, the most recent National Nutrition Survey found that the majority of Australians (92.1% or almost 20 million people) did not eat legumes on either day of the survey.

So why don’t more people enjoy legumes? GLNC’s 2014 Grains and Legumes Consumption and Attitudinal Study found that the biggest barrier to legume consumption was simply that Australians do not think to include them in their diet or the meals they prepare.(2) As legumes are widely accessible and affordable there is lots of potential for Australians to improve their diet quality and reduce risk of disease in the long term by taking the simple step of enjoying legumes more often.

Starting this healthy habit

A good starting goal for those who don’t eat legumes regularly is to aim to eat a variety of legumes at least 2-3 times each week as part a balanced diet. This can easily be achieved by adding chickpeas or beans to your salads, choosing soy milk more often, enjoying hummus dip as a snack or simply adding a can of drained and rinsed canned beans/lentils to your favourite recipe (i.e. spaghetti with red lentils).

For more tips and tricks to help you, your friends or family start this healthy habit check out our family friendly cookbook An Everyday Guide to Cooking with Legumes as well as our Legumes - Start a Healthy Habit fact sheet.

References:

1. Blue Zones [cited 2015 March ]. Available from: http://www.bluezones.com/.
2. GLNC. 2014 Australian Grains and Legumes Consumption and Attitudinal Report. Unpublished: 2014.
3. NHMRC. Australian Dietary Guidelines: Providing the scientific evidence for healthier Australian diets 2013 [cited 2015 January]. Available from: http://www.nhmrc.gov.au/guidelines-publications/n55.
4. Fardet A, Boirie Y. Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews. Nutrition reviews. 2014:n/a-n/a.
5. GLNC. Secondary Analysis of the National Nutrition and Physical Activity Survey 2011-2012 Unpublished: 2014.