Fasting Overnight During Simulated Night Shift Mitigates Glucose Impairment

Summary

This lab trial put healthy adults on four simulated night shifts and assigned them to one of three eating plans: no calories overnight (fast at night), small snacks at night, or full meals at night (everyone ate the same total calories overall). Night work made people’s bodies less sensitive to insulin across the board, but those who fasted at night had a much smaller rise in blood sugar after a glucose drink than those who ate or snacked overnight. They also showed signs that the body released insulin more effectively right after the drink.
The study also tracked NEFA AUC—the total amount of “free fatty acids” floating in the blood during the test. NEFA totals went up when people ate or snacked at night, but not when they fasted, suggesting overnight eating pushed more fat into the bloodstream. No adverse events were reported.