It is the glycaemic response to, not the carbohydrate content of food that matters in diabetes and obesity: The glycaemic index revisited

David Unwin,David Haslam,Geoffrey Livesey

doi:10.4102/jir.v1i1.8

David Unwin, David Haslam + Show 1 more

Open Access

https://doi.org/10.4102/jir.v1i1.8

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Abstract

Background: The low-carbohydrate diet for diabetes and obesity is over 200 years old. A new lease of life comes with evidence for its beneficial effects supplied by research into the value of low-glycaemic index (GI) foods in diabetes control. While trialling this approach it became evident that professionals and patients had previously misunderstood the index leading to errors in food choices. Aim: To explore the importance of the GI for those with T2D and improve understanding of the likely effect of various foods on blood glucose. Setting: A 9000 patient United Kingdom (UK) primary care practice.Methods: Relevant supporting studies were examined and data were reviewed from a previously published case-series with new data relating to the effect of the approach on the whole practice over a period of three years. An improved interpretation of the GI using a ‘teaspoons of sugar equivalent’ was developed as an aide to understanding. We looked at quality markers for diabetes and obesity such as HbA1c and weight. Results: Our approach was readily understood by patients and staff, helping to achieve significant improvements in diabetes control and weight. The practice as a whole compared to the average for the area was found to have; a significantly better quality of diabetes control, lower obesity prevalence whilst spending around £40 000 less per year on drugs for diabetes.Conclusion: Greater consideration needs to be given to the harmful effects of high-GI starchy foods in the treatment and prevention of obesity and diabetes. Patient compliance and outcomes justify our approach in a primary care setting.

Highlights

There is currently substantial debate about the merits of an imminent United Kingdom (UK) tax on sugar-sweetened beverages and snacks that are high in sugar.[1]
While working in the area of dietary choices for patients with obesity and type 2 diabetes (T2D) in a primary care setting,[3] we observed that many health professionals and patients when considering dietary choices were confused by the relative merits of using carbohydrate content of food in grams versus the foods’ glycaemic index (GI)
Many erroneously assumed table sugar to affect blood glucose far more than the carbohydrate in a baked potato, for example, and others wrongly assumed that carbohydrate in different foods had a similar effect on blood glucose

Summary

Introduction

There is currently substantial debate about the merits of an imminent United Kingdom (UK) tax on sugar-sweetened beverages and snacks that are high in sugar.[1]. GI and glycaemic load (GL) values have been tabulated for the various carbohydrate foods.[4] The position of any food in a GI or GL league table is determined by the food’s effect on post-prandial blood glucose. This is determined by both the type and the amount of carbohydrates in the food and how quickly the food can be digested. A new lease of life comes with evidence for its beneficial effects supplied by research into the value of low-glycaemic index (GI) foods in diabetes control While trialling this approach it became evident that professionals and patients had previously misunderstood the index leading to errors in food choices

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Conclusion