Trying to Lose Weight? Scientists Found an Unexpected Connection to Your Bedtime

New research suggests the clock on your nightstand may deserve as much attention as the number on your bathroom scale. Scientists at New York University found that falling asleep earlier was associated with greater weight loss, even when people weren’t sleeping longer.

In a study published in Nursing Research, each hour earlier participants fell asleep was associated with approximately 1.3 additional pounds lost over eight weeks. The catch? Coaching people to change their bedtime didn’t significantly improve weight loss.

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Why Sleep Timing May Matter More Than Expected

Researchers followed 196 adults ages 21 to 64 with prediabetes who typically slept fewer than 6.5 hours nightly. Everyone received guidance on nutrition, exercise, and stress management. Half also received coaching designed to gradually move bedtime earlier.

“When we fall asleep—not just how much we sleep—seems to be an important and overlooked factor for weight loss and metabolic health,” said Susan Kohl Malone, PhD, an assistant professor at NYU Rory Meyers College of Nursing and the study’s lead author, in a university announcement.

The researchers suspect earlier sleep could reduce opportunities for late-night snacking and better align eating with the body’s internal clock.

“In contrast, falling asleep earlier may limit late-night eating and better align food intake with the body’s optimal metabolic window,” Malone explained.

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The Weight-Loss Results Came With a Catch

Both groups lost weight, but additional sleep coaching produced no statistically significant advantage. Neither group experienced significant improvements in glucose control.

Participants receiving sleep coaching did report better sleep quality and less daytime sleepiness.

“While we expected that extending sleep would improve glucose levels and weight loss in adults with prediabetes who sleep for shorter periods, this wasn’t the case in our study,” Malone said.

“However, our findings do raise the possibility that earlier sleep onset, independent of sleep duration, could be a promising target for improving metabolic health.”

Importantly, the weight-loss association came from a secondary analysis. It doesn’t prove that moving bedtime earlier causes pounds to disappear.

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What to Do Before Changing Your Bedtime

For anyone trying to lose weight, the findings offer another reason to examine sleep habits alongside food choices and exercise.

An earlier, consistent bedtime may be worth considering, especially if late nights encourage unnecessary snacking. But eight weeks of research cannot establish lasting weight-loss benefits.

The takeaway: Protect adequate sleep, maintain healthy routines, and don’t mistake a promising association for a proven shortcut.

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This story was originally published by Men’s Journal on Nov 8, 2026, where it first appeared in the Health section. Add Men’s Journal as a Preferred Source by clicking here.