Nutritional Management of Diabetes Mellitus

Book Preface

The Ancient Greeks were the first to advocate diet and lifestyle management for people with diabetes. Until the discovery and use of insulin in the 1920s and suphonylureas in the 1940s, diet and lifestyle intervention were the only treatment options available. For people with Type 1 diabetes this was woefully ineffective and consisted of near starvation diets imposed on already severely malnourished individuals. While such diets may have prolonged life by a few months, an inevitable early death from ketoacidosis was all too often replaced with death from infections due to the severe malnutrition and other comorbidities. The introduction of insulin radically reduced the death rates from ketoacidosis and problems associated with malnutrition, however, survival brought other lethal problems in the form of microvascular and macrovascular disease.

The dietary management of Type 1 diabetes over the last 80 years has had to adapt to the many changes in insulin formulations as well as changes in staple foods and eating patterns. Over the years the premise for the dietary advice given, of optimising growth while minimising diabetes associated complications, has not changed. By contrast the dietary advice given has radically changed in response to advances in our understanding of the biochemical and physiological mechanisms involved in diabetic complications. Today the dietary advice offered for people with Type 1 diabetes has little resemblance to the advice given by R. D. Lawrence three-quarters of a century ago. R. D. Lawrence’s diet advocating a high-fat and low-carbohydrate intake has been replaced by the more healthy low-fat and high-carbohydrate diets of today. To what extent today’s dietary advice will resemble that in 75 years time, will, we believe, reflect the quality of the scientific evidence behind this advice. Since the advent of insulin and oral agents, other changes to the dietary management of diabetes have included the way dietary advice is imparted.

There has been a move away from prescriptive diets given by authoritarian physicians towards trying to achieve the necessary dietary and lifestyle changes through educating individuals to a level such that they can make their own informed choices regarding their management. However, a greater understanding of the factors that influence the uptake of lifestyle advice is required if more effective dietary management for people with diabetes is to be achieved in the future.

Despite the availability of several different classes of oral hypoglycaemic agents for the management of Type 2 diabetes, dietary and lifestyle management remains crucial for the optimal effectiveness of these drugs. It might at first appear strange that this book contains only a summary chapter dealing with Type 2 diabetes. This is because the lifestyle messages for the management of people with Type 2 diabetes are covered in other chapters throughout the book, including those addressing guidelines, exercise, counselling and obesity. Lifestyle and dietary changes for people with Type 2 diabetes are required, not only for glycaemic control but also for reducing important cardiovascular risk factors.

The aim of this book is to provide a practical guide for the dietary management of diabetes based on basic physiological principles as well as nutritional and clinical evidence. We hope this book will aid health professionals to provide their patients with informed evidence-based advice in a way most likely to achieve the meaningful nutritional changes that will improve their quality of life.