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.