A simple change in sleep patterns has helped some people lose weight

An analysis of data from a randomized study conducted by the Rory Meyers College of Nursing at New York University found that every hour participants fell asleep earlier resulted in about a pound of weight loss over eight weeks, although this finding does not prove that going to bed earlier leads to weight loss.

“When we fall asleep, not just how much sleep we get, appears to be an important and overlooked factor in weight loss and improved metabolism,” says Susan Col Malone, an assistant professor at the College of Nurses and lead author of the study.

The study, published in the journal Nursing Research, involved 196 adults diagnosed with prediabetes who typically slept less than 6.5 hours a night.

Half of the group took part in an eight-week education course on diet, exercise and stress management. The other half of the participants underwent similar training as well as behavioral coaching designed to gradually get them to bed early.

The researchers tracked participants’ blood sugar levels, sleep and activity using sensors, sleep logs and wrist monitors. In no group did blood sugar levels improve significantly. Both groups lost weight, but those who received sleep training did not lose much more weight than those who received only lifestyle training.

“While we expected increased sleep duration to improve glucose levels and reduce weight in adults with prediabetes who sleep for shorter periods, this did not happen in our study,” Malone said.

Participants who underwent sleep instruction reported improved sleep quality and less daytime sleepiness, and gradually started going to bed earlier.

In a separate analysis in both groups, participants who changed their sleep patterns to earlier ones tended to lose more weight.

The researchers suggested that the body’s internal clock could help explain the findings.

Late bedtime can increase exposure to artificial light, which can activate the body’s response to stress and affect hormones that regulate hunger. Late wakefulness also coincides with hours when a person's insulin sensitivity is lowest, Fox News notes.

“In contrast, falling asleep earlier may restrict eating late at night and better align food intake with the body’s optimal metabolic period,” Malone said.

The study lasted only eight weeks, meaning it’s unclear whether participants would be able to go to bed earlier or maintain weight loss in the long run.

Even though participants wore wrist monitors, key sleep metrics such as sleep quality and daytime sleepiness depended heavily on reports received by the participants themselves. The findings also point to a relationship between the study group, rather than a proven cause and effect.

According to Malone, participants who underwent sleep coaching fell asleep on average about 12 minutes earlier, which did not lead to a noticeable improvement in blood sugar levels.