Glycemic Index, Glycemic Load & Glycemic Response:
an International Scientiﬁc Consensus Summit
Oldways partnered with the Nutrition Foundation of Italy (NFI) to organize an International Consensus Summit on Glycemic Index, Glycemic Load and Glycemic Response on June 6-7, 2013 in Stresa, in the Italian Lakes District, north of Milan. The purposes of this meeting were:
- to bring together international experts in the ﬁeld of carbohydrates and health in order to present/discuss the issues related to the role of glycemic index/glycemic load/glycemic response in the prevention and treatment of disease; and
- to develop a solid Scientiﬁc Consensus Statement on what can be agreed upon regarding glycemic index/glycemic load/glycemic response. The document was drafted by speakers at the end of the Summit in a separate afternoon session on June 7.
As you can see through the supporting materials below, this conference produced an important consensus statement about glycemic health and quality carbohydrates.
Clink on the link above to view the news release which describes the signiﬁcance of the Summit and Glycemic Index, Glycemic Load & Glycemic Response Scientiﬁc Consensus Statement.
Click on the link above to read our Oldways Table blog reporting on the Summit in Stresa, click here.
Consensus Statement of the Glycemic Summit
Stresa, Italy • June 7, 2013
This Consensus Statement was the culmination of the International Scientiﬁc Consensus Summit on Glycemic Index, Glycemic Load and Glycemic Response, organized June 6-7, 2013 in Stresa, Italy. Another outcome of the Summit was that the participating international panel of experts formed the “Carbohydrate Quality Consortium (CQC)” to meet and discuss the importance of carbohydrate quality in addition to quantity.
- Carbohydrates present in diﬀerent foods have distinct physiological eﬀects, including eﬀects on post-prandial glycemia (PPG), also known as the glycemic response1, with diﬀerent implications for health.
- Reducing PPG is recognized as a beneﬁcial physiological eﬀect (Ceriello and Colagiuri 2008, Levitan et al. 2004, Coutinho et al. 1999, EFSA 2011).
- Ways to reduce PPG include slowing carbohydrate absorption by consuming low glycemic index (GI)2 and glycemic load (GL)3 foods to reduce the dietary GI and GL (Jenkins et al. 1981, Salmeron et al. 1997).
- The GI methodology is a suﬃciently valid and reproducible method for diﬀerentiating foods based on their glycemic response (Wolever 2013, Brouns et al. 2005).
- The GI quantiﬁes speciﬁc physiological properties of carbohydrate-containing foods as inﬂuenced by the food matrix. These characteristics extend beyond their chemical composition of food and include delaying gastric emptying and reducing the rate of digestion and small intestinal absorption.
- When considering the macronutrient composition, the GL/1000kJ (the product of GI and available4 carbohydrate content) is the single best predictor of the glycemic response of foods (Bao et al. 2011).
- There is convincing evidence from meta-analyses of controlled dietary trials that diets low in GI improve glycemic control in people with type 2 and type 1 diabetes (Giacco et al. 2000, Brand-Miller et al. 2003, Livesey et al. 2008, Thomas and Elliot 2010, Jenkins et al. 2012).
- There is convincing evidence from meta-analyses of prospective cohort studies that low GI/GL diets reduce the risk of type 2 diabetes Barclay et al. 2008, Livesey et al. 2013).
- There is convincing evidence from a large body of prospective cohort studies that low GI/GL diets reduce the risk of coronary heart disease (Liu et al. 2000, Mirrahimi et al. 2012, Fan et al. 2012).
- The proof of principle for the concept of slowing carbohydrate absorption is the use of alpha-glucosidase inhibitors (acarbose etc.) to reduce progression to type 2 diabetes and coronary heart disease (Chiasson et al. 2002, Chiasson et al. 2003).
- The quality of carbohydrate-rich foods as deﬁned by GI/GL is particularly important for individuals who are sedentary, overweight and at increased risk of type 2 diabetes (Salmeron et al. 1997, Ludwig et al. 2002).
- Potential mechanisms for reduction of type 2 diabetes include evidence that low GI/GL diets improve insulin sensitivity and beta-cell function in people with type 2 diabetes and those at risk for type 2 diabetes (Rizkalla et al. 2004, Solomon et al. 2011).
- Potential mechanisms for reduction of coronary heart disease include evidence that low GI/GL diets improve blood lipids and inﬂammatory markers including C-reactive protein (CRP) (Frost et al. 1999, Liu et al. 2001, Wolever et al. 2008, Shikany et al. 2010. Goﬀ et al. 2013).
- Probable evidence exists for low GI/GL diets in reducing total body fat mass and in weight management (Larsen et al. 2010, Murakami et al. 2013, Bouché et al. 2002, McMillan-Price et al. 2006, Ebbeling et al. 2005).
- The GI complements other ways of characterizing carbohydrate-foods, such as ﬁber and whole grain content (Riccardi et al. 2008, Slavin 2008).
- Low GI and Low GL should be considered in a context of a healthy diet.
- Given the rapid rise in diabetes and obesity there is a need to communicate information on GI/GL to the general public and health professionals.
- This should be supported by inclusion of GI/GL in dietary guidelines and in food composition tables.
- In addition package labels and low GI/GL symbols on healthy foods should be considered.
- More comprehensive high-quality food composition tables need to be developed for GI/GL at the national level.
Scientiﬁc Consensus Committee:
David J.A. Jenkins, MD, PhD, DSc, University Professor and Canada Research Chair in Nutrition and Metabolism, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Director, Risk Factor Modiﬁcation Centre, St. Michael’s Hospital (Toronto, Canada)
Walter C. Willett, MD, DrPH, Fredrick John Stare Professor of Epidemiology and Nutrition, Chair, Department of Nutrition, Harvard School of Public Health (Boston, USA)
Livia Augustin, PhD, Research Fellow, Risk Factor Modiﬁcation Centre, St. Michael’s Hospital (Toronto, Canada)
Sara Baer-Sinnott, President, Oldways (Boston, USA)
Alan W. Barclay, PhD, Head of Research, Australian Diabetes Council; Chief Scientiﬁc Oﬃcer Glycemic Index Foundation (Sydney, Australia),
Inger Björck, PhD, Professor and Managing Director Antidiabetic Food Centre, Lund University (Lund, Sweden)
Jennie C. Brand-Miller, PhD, Professor, Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, University of Sydney (Sydney, Australia)
Furio Brighenti, DrPH, Professor of Human Nutrition, Department of Food Science University of Parma (Parma, Italy)
Anette E. Buyken, PhD, Research Associate, Department of Nutritional Epidemiology, University of Bonn (Bonn, Germany).
Antonio Ceriello, MD, Head of Research at the Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) (Barcelona, Spain)
Cyril W.C. Kendall, PhD, Research Associate, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto (Toronto, Canada) and Adj. Professor College of Pharmacy and Nutrition, University of Saskatchewan (Saskatoon, Canada)
Carlo La Vecchia, MD, Chief, Department of Epidemiology, Mario Negri Institute, and Professor of Epidemiology, University of Milan, (Milan, Italy)
Geoﬀ Livesey, PhD, Director, Independent Nutrition Logic (Wymondham, UK)
Simin Liu, MD, ScD, Professor, Departments of Epidemiology and Medicine, Brown University (Providence, USA)
Andrea Poli, MD, Scientiﬁc Director, Nutrition Foundation of Italy (Milan, Italy)
Gabriele Riccardi, MD, Full Professor of Endocrinology and Metabolic Diseases, Department of Clinical Medicine and Surgery, Federico II University (Naples, Italy)
Salwa W. Rizkalla, MD, PhD, DSc, Senior Researcher, National Institute of Health and Medical Research (INSERM) U 872, team 7, Research centre in human nutrition, ICAN Institute of Cardiometabolism & Nutrition, University Pierre et Marie Curie-Paris 6, Centre of Research in Human Nutrition, Pitié Salpêtrière Hospital (Paris, France).
John L. Sievenpiper, MD, PhD, Toronto 3D Knowledge Synthesis and Clinical Trials Unit, Clinical Nutrition and Risk Factor Modiﬁcation Centre, St. Michael’s Hospital (Toronto, Canada), Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University (Hamilton, Canada).
Antonia Trichopoulou, MD, PhD, Professor and Director, World Health Organization Collaborating Centre for Food & Nutrition, Department of Hygiene and Epidemiology, University of Athens Medical School, and Vice President, Hellenic Health Foundation (Athens, Greece)
Thomas M.S. Wolever MD, PhD, Professor, Department of Nutritional Sciences, University of Toronto (Toronto, Canada)
This International Scientiﬁc Consensus Summit was co-organized by the Nutrition Foundation of Italy and Oldways.
Consumer-Friendly Deﬁnitions and Tip Sheet from the Glycemic Summit
Consumer Friendly Deﬁnitions for Understanding Glycemic Health
Human bodies depend on a steady supply of glucose (blood sugar) as their principal fuel, in order for muscles to stretch and contract, nerves to ﬁre, brains to function – and so much more. Glucose comes from carbohydrates, so the quality and quantity of carbohydrates we eat hugely impacts our energy levels and overall health.
Too little glucose, and we starve many bodily functions (especially the brain, which uses 11-20% of the glucose we produce). Too much, and our body scrambles to produce enough insulin to process all that blood sugar – and we may develop heart disease, eye, kidney and nerve damage. Ideally, our food delivers a steady stream of just the right amount of glucose.
But how do we distinguish foods, meals and diets that raise our blood sugar too high and too fast from those that dole out their fuel slowly and steadily to support good health? Understanding glycemic index, glycemic load and glycemic response can help.
Glycemic Index (GI), developed by David Jenkins, Thomas Wolever and colleagues at the University of Toronto in 1981, ranks the quality of individual carbohydrate-rich foods on a scale of 1-100 by measuring how glucose levels rise after someone eats an amount of that food containing 50 grams of carbohydrate. Foods with a low GI score (under 55) provide steady fuel to support energy levels and overall health, while those with a high GI score (70 and up) are likely to provide an unhealthy quick rush of blood sugar followed by a sharp crash.
Walter Willett and colleagues at the Harvard School of Public Health created the concept of Glycemic Load. Glycemic Load (GL) combines quality and quantity, allowing us to rank how the typical serving size of a food aﬀects blood sugar. A GL of 0-10 is considered low (slow, steady conversion to blood sugar; healthier), while a high GL is 20 and up (ﬂash and crash – tough on health and energy levels). Research shows why GI and GL both matter: a low glycemic load can be achieved either by eating small amounts of high GI carbs, or large amounts of low-GI carbs, and some studies show that the latter approach (i.e. low-GI, low-GL) is best of all for health.
While both GI and GL are useful measures of our glycemic response to certain foods or dishes, our body’s overall Glycemic Response – our management of blood sugar over time – also appears to depend on our total diet and lifestyle.
As useful as GI, GL, and GR can be, it’s important to keep in mind that understanding the eﬀect of carbohydrates on blood sugar is just one part of choosing a healthy diet. The quality of fats and proteins matters too, as do ﬁber, vitamins, minerals and other factors. The bottom line? Eating a wide variety of delicious, whole, minimally-processed foods, guided by the latest science in all these areas, is the way to go.
Tips for a Lower GI-GL Diet
The refreshing news is that reaping the beneﬁts of a low-glycemic diet doesn’t mean only looking at numbers. The principle of glycemic health is important, and traditional eating patterns such as the Mediterranean Diet oﬀer a good example of how to enjoy delicious food while safe-guarding your good health.
In general, whole and minimally-processed foods are better choices than highly-processed foods, for keeping blood sugar and energy steady.
Here are a dozen ideas anyone can use to easily bring the science of glycemic index, glycemic load and glycemic response to their everyday meals and snacks.
- Choose traditional muesli, or longer-cooking oatmeal or porridge (not instant) instead of processed ﬂakes or puﬀs.
- Eat a variety of intact whole grains, and be sure not to overcook them. Intact grains such as barley, wheatberries and ryeberries have a low glycemic index, especially when they’re cooked al dente.
- Pasta has a low glycemic index, and it’s important to cook it al dente. Enjoy pasta with plenty of vegetables and beans or ﬁsh for a healthy pasta meal.
- Look for longer-cooking varieties of rice. Cook extra portions and freeze them for later use.
- Favor whole fruits over fruit juice, and enjoy juice in small quantities or mixed with sparkling water.
- Skip the ﬂuﬀy, light breads. Traditional dense grainy bread has a much lower glycemic index.
- Eat legumes. Serve lentil soup, a bean-ﬁlled chili, or a chickpea salad. Add beans to soups, salads, pasta and other dishes.
- Certain ﬁbers, including resistant starch (found in foods including beans, bananas, cold pasta and potato salads), lower your body’s glycemic response. A mostly-plant-based diet provides a good variety of diﬀerent types of ﬁber.
- Add zing to your meals. Acidic foods lower your glycemic response, so squeeze lemon juice on your vegetables, ﬁsh or chicken; enjoy your salad with oil and vinegar; and add a splash of vinegar to soups or vegetable stews.
- Enjoy snacks like carrots with hummus, apple slices with nut butter, or plain yogurt with fresh or frozen berries.
- Enjoy balanced meals and snacks. Eating healthy fats and lean protein with carbohydrates lowers the overall glycemic load of a meal or snack.
- Practice portion control. Too much of even a healthy food is, well, too much. Serve yourself a modest portion, eat slowly and mindfully, and reﬂect before you reach for more.
Scientiﬁc Organizing Committee
- Livia Augustin, PhD, Risk Factor Modiﬁcation Centre, St. Michael’s Hospital (Toronto, Canada)
- Cyril Kendall, PhD, Research Associate, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto (Toronto, Canada)
- Andrea Poli, MD, Scientiﬁc Director Nutrition Foundation of Italy (Milan, Italy)
- Sara Baer-Sinnott, President Oldways (Boston, USA)
Scientiﬁc Advisory Committee:
- Jennie Brand-Miller, PhD, Professor, Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, University of Sydney (Sydney, Australia)
- Furio Brighenti, DrPH, Professor of Human Nutrition, Department of Food Science University of Parma (Parma, Italy)
- David Jenkins, MD, PhD, DSc, University Professor and Canada Research Chair in Nutrition and Metabolism, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Director, Risk Factor Modiﬁcation Centre, St. Michael’s Hospital (Toronto, Canada)
- Walter Willett, MD, DrPH, Fredrick John Stare Professor of Epidemiology and Nutrition Chair, Department of Nutrition, Harvard School of Public Health (Boston, USA)
- Cynthia Harriman, Oldways (Boston, USA)
- Anna Miniotti, Nutrition Foundation of Italy (Milan, Italy)
- Abby Sloane, Oldways (Boston, USA)
NFI – Nutrition Foundation of Italy
NFI - Nutrition Foundation of Italy was created in December 1976 with the goal of enabling interaction and collaboration with government bodies, universities and industry to contribute to the development of scientiﬁc research, to the exchange of information in the ﬁeld of nutrition and to the promotion of interdisciplinary researches in this area. NFI has a Scientiﬁc Committee of Experts with recognized competence in the diﬀerent disciplines related to food and beverage.
NFI is partner of the European Nutrition Foundations Network.
NFI- Nutrition Foundation of Italy
Viale Tunisia 38 — 20124 Milan — Italy
t: +39 02 76006271 • f: +39 02 76003514
Oldways and the Nutrition Foundation of Italy sincerely thank the following companies for their unrestricted ﬁnancial support of this International Scientiﬁc Consensus Summit.