Final answer:
The best patient statement indicating a proper understanding of the dietary instructions for a pregnant client with diabetes mellitus is the need to increase dietary fiber to manage blood glucose levels and prevent constipation, rather than excessively increasing fat or glucose intake.
Step-by-step explanation:
The correct statement indicating that the patient understands the dietary instructions given by the nurse would be option D: "I will need to increase fiber in the diet to help control the blood glucose level and prevent constipation." Increasing dietary fiber is beneficial for patients with diabetes in managing blood glucose levels and maintaining gastrointestinal health. In contrast, excessive fat intake or adding extra glucose to the diet would likely exacerbate hyperglycemia, which is not recommended for patients with diabetes mellitus. Instead, following a balanced diet that includes a controlled amount of carbohydrates, combined with adequate proteins, vitamins, and healthy fats, is essential. During pregnancy, it is necessary to consume an additional 300-400 calories per day, primarily during the last trimester, rather than doubling caloric intake. It's critical to emphasize the importance of fiber-rich foods, such as fruits, vegetables, and whole grains as part of the diet.