MOD Diet in Gestational Diabetes Mellitus

Gestational diabetes (GDM) is a condition of high blood glucose (or "blood sugar") during pregnancy. GDM can cause harmful short-term and long-term health effects for mom and baby. Diet therapy is an effective way to achieve normal blood glucose for women with GDM, but the best diet is unknown. Diet strategies that improve blood glucose in GDM and that patients can follow are needed for better clinical care. In studies of non-pregnant individuals with diabetes, eating a high fat/protein breakfast as the only dietary change was enough to improve glucose control. Because highest blood glucose readings in GDM usually occur after breakfast, a high fat/protein breakfast could also improve glucose control in GDM. In this study, two dietary strategies for improving blood glucose will be compared. Ten women newly diagnosed with GDM (\<30 weeks in pregnancy) will be enrolled in a 12-day cross-over controlled feeding study with a high fat/protein breakfast, which is named a 'Macro-Optimized Diet' (MOD) or standard care diet (SC). In other words, subjects will have all food provided to them, and they will consume each diet for a few days while researchers monitor their blood glucose. Most nutrition aspects of the two diets will be similar, but the MOD diet will vary the timing of eating carbohydrate, protein, and fat to achieve fewer carbs at breakfast. After the 12-day controlled feeding period, participants will continue one of the study diets (as randomized) until delivery. During this time, research team dietitians will provide personalized nutrition education to support GDM self-management. The study will evaluate whether the diet is acceptable to women with GDM and their clinic providers. Data to be collected include blood glucose data, patient and provider feedback on diet acceptability, weight gain, the number of participants who are prescribed blood glucose control medications, and infant weight. These data will be used to evaluate trends pointing to whether one diet is more effective.