Gestational diabetes patients who do not eat breakfast violate the nutritional principles of regular meals, timing and rationing, the harm is as follows: 1. It will affect blood sugar fluctuations, not eating breakfast will cause hypoglycemia, cause hunger, the amount of food at noon will increase, the blood sugar rises sharply after meals, hungry meal, full meal, which is not conducive to blood sugar control. In case of pregnant women who use insulin, it is also not easy to adjust the dosage, so set meals, timed and quantitative, and regular meals. On the one hand, it helps the stability of endocrine and metabolism, on the other hand, it can promote the effective adjustment of medication regimen; 2. It can cause insufficient nutritional intake and insufficient or too slow weight gain of pregnant mothers, which can bring bad outcomes to both pregnant mothers and fetuses.