From a Sleep Review Magazine online article:
When people are awake during the night, their behaviors are often mismatched with their internal body clocks. This can lead to nighttime eating, which can influence the way the body processes sugar and could lead to a higher risk in diabetes. “What happens when food is eaten when you normally should be fasting?” Scheer asked the audience. “What happens is that your glucose tolerance goes out the window….So your glucose levels after a meal are much higher.” This can increase people’s risk for diabetes.
Frank Scheer, PhD, professor of medicine at Harvard Medical School and director of the medical chronobiology program at Brigham and Women’s Hospital in Boston, says disruption of the body’s circadian rhythms may be one major reason why more Americans are living with preventable diseases. During his keynote talk at the 2019 AAST annual meeting in St. Louis, he outlined how recent research supports the hypothesis that higher rates of shiftwork and other forms of nighttime disruption could be contributing to increased rates of obesity, diabetes, and other common ailments.