Some studies have shown that if women will eat and drink during labor, they can reduce the length of the labor by as much as 90 minutes. Labor is very hard work, and the body needs the energy to work effectively. Dehydration and low blood sugar, means more painful contractions and slower labor.
Fatigue combined with a slower labor may make a woman feel that she needs to resort to medications.
Good things to have on hand are clear liquids, such as broth, or herbal teas such as raspberry with honey for energy. Some mothers like toast with a tiny bit of peanut or almond butter, or banana with honey. As long as you don't have an epidural, there is no reason why you cannot eat to hunger and drink to thirst in labor.
Just imagine trying to run a marathon after having nothing to eat for many hours. You would most likely not be successful. Labor is like a marathon, and your body needs reserves of energy that simply cannot be met by IV hydration. So talk to your care providers about eating and drinking in labor because birth is normal, and normal people eat !