Study
The subjects in the control group did not change their diet. Their nighttime fasting period was 11-13 hours. The subjects in the experimental group ate nothing at all three hours before going to sleep. As a result, their nighttime fasting period was 13-16 hours long.
The trial lasted 45 days.
Results
Before and after the trial, the researchers gave their subjects 75 grams of glucose and then monitored how much their insulin levels rose and how quickly their glucose levels fell. The faster this process, the better.
One measure of this is the insulinogenic index. In healthy people, it usually lies somewhere between 1 and 1.5. People with pre-stage type 2 diabetes often have an index between 0.7 and 0.8.
In the experimental group, the index rose from 0.9 to 1.2. That's a 33 percent increase. This suggests that pancreatic function improved from just barely healthy to healthy.
Click on the table below for a larger version.
During healthy sleep, blood pressure and heart rate decrease by 10-20 and 15-20 percent, respectively. If this decrease is too small, the heart muscle cannot recover properly overnight, and the risk of heart disease increases.
In the experimental group, the nocturnal decrease in diastolic blood pressure and heart rate decreased by an additional 3.5 and 5 percent, respectively.
Conclusion
"These findings have important clinical implications, particularly for middleaged and older adults at risk for cardiometabolic disease", the researchers write.
"Sleep-aligned fasting represents a feasible, nonpharmacological intervention for cardiometabolic disease risk reduction."
