Amazingly, this is actually a relaxation of the previous ACOG guidelines, which restricted women to ice chips only.
How did we so completely lose the concept of a woman's bodily autonomy?
Thanks to Dr. Fischbein for bringing this to my attention. He has a good article in response, a portion of which I'll quote here:
Policies restricting food and liquid intake date from an era when laboring women were routinely given general anesthesia and risked aspirating food into the lungs. Modern anesthetic techniques have virtually eliminated this risk, which is further reduced by the fact that only a tiny minority of laboring women, even among those who deliver via cesarean section, actually receive general anesthesia.
"The women I care for eat when they are hungry and drink when they are thirsty, all without asking for ACOG's permission first," said Elizabeth Allemann, MD. "Women deserve to be fully informed about what the evidence actually shows, and it's time that the medical profession abandoned policies based on the outdated and paternalistic idea that patients should play no role whatsoever in the decision-making process."