In most cases it can be kept under control with careful monitoring of your diet and regular exercise. It is also very likely that once the pregnancy is over you have no further problems with diabetes, though you would need to continue to be careful with your health: The majority of gestational diabetes symptoms go away after the baby is born, but women who had this are more likely to develop Type 2 diabetes later on, so it would be sensible to make some permanent changes to your lifestyle.

You will get more advice from your doctor or a dietician, but in general you will be advised to eat regular meals - skipping meals or snacking isn't good for your blood sugar levels. You should have a fair amount of carbohydrates like rice, pasta, porridge etc, and fresh fruit and vegetables, and take plenty of exercise both to keep your weight down and to help your general health. You can get more information about this here.