The diet for the diabetic mother needs to limit excess maternal-foetal transfer of glucose. As post-prandial hyperglycaemia is the time of maximal maternal-foetal glucose transfer, treatment interventions need to target this period (6). Controversy exists on how best to achieve this. Some authorities recommend limiting carbohydrate at the expense of increasing dietary fat, while others favour high-carbohydrate diets with a low glycaemic response. It is the authors' belief that promoting diets that actively limit carbohydrate over fat sends out the wrong lifetime educational message. Clinical studies suggest that it is the type of carbohydrate and fat rather than the absolute amount that dictates the glycaemic and metabolic responses to a meal. As a degree of gastric stasis is common in pregnancy, the glycaemic response of many carbohydrates is blunted.
The American Diabetic Association (62) recommend limiting carbohydrate to 40% of the total energy content by increasing dietary fat to 40%. This advice is based on clinical studies showing women with GDM have better glycaemic control when consuming less than 45%, rather than more than 45%, of their calorie intake as carbohydrate (72,73). The American approach gives no acknowledgement to the fact that different ingested carbohydrates have different glycaemic responses as measured by their glycaemic index (74).
British advice on the diabetic diet in pregnancy does not recommend limiting carbohydrate to 40% of the total energy and indeed suggests this figure should be nearer 55%, with the majority of carbohydrate having a low glycaemic index (75). Low glycaemic index diets can in fact increase insulin sensitivity in both pregnant and non-pregnant individuals (42-44,76). In pregnancy glycaemic control deteriorates when refined carbohydrate contributes more than 45% of the total energy (72). By contrast when refined carbohydrates are exchanged for low glycaemic index carbohydrates, 60% of the total dietary energy can be consumed in this form without any change in glucose tolerance (42-44). As the glycaemic response to rapidly absorbed refined sugars is greatest in the early morning, advice on suitable commercial breakfast cereals should be given (77).
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Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...