Eating onions in moderation has little effect on the blood glucose of gestational diabetics and provides some nutrients, so gestational diabetics can eat onions normally. Gestational diabetics need to control their blood glucose level strictly, and the standard of control should be stricter than non-pregnant people. Onions are a low glycemic index food and moderate consumption of onions has little effect on blood sugar. It should be noted that onions are not a substitute for medication to lower blood glucose, and patients with gestational diabetes who consume too many onions are still at risk for elevated blood glucose levels. In conclusion, patients with gestational diabetes can eat onions, but not in large quantities, and need to test their blood glucose levels regularly.