What is the dietary requirement before undergoing the O'Sullivan Glucose Tolerance Test?

The requirement for a minimum of 150g of carbohydrates per day before undergoing the O'Sullivan Glucose Tolerance Test is based on the need to ensure that the patient is in a state of normal carbohydrate metabolism. Consuming this amount of carbohydrates helps the body to adequately prepare for the test by inducing an appropriate insulin response and ensuring that glycogen stores are replenished.

This preparation is crucial because a diet too low in carbohydrates may lead to inaccurate results, potentially resulting in a false positive or negative for gestational diabetes. The aim is to simulate normal dietary habits so that the patient's glucose metabolism can be accurately assessed during the test.

Any lower carbohydrate intake would not provide a true reflection of how the patient's body processes glucose, which is why the 150g threshold is important. This amount allows for the maintenance of baseline blood glucose and insulin levels, facilitating an accurate diagnostic assessment.

In contrast, higher carbohydrate targets, such as those listed in other choices, exceed what is needed to prepare for the test and may not be necessary for accurate results. Failing to follow the dietary guidelines can lead to misleading interpretations of glucose tolerance.