Simple bedtime change may help some individuals lose weight, study finds

An analysis of a trial involving adults with prediabetes found that falling asleep earlier was associated with greater weight loss over eight weeks. The finding suggests sleep timing may be relevant to weight and metabolic health, but it does not show that changing bedtime causes weight loss.

The study assessed 196 adults who usually slept fewer than 6.5 hours a night. Both groups received lifestyle education, while one also had coaching to shift bedtime earlier; neither group had significant blood sugar improvements, and the coached group did not lose significantly more weight. Across both groups, each hour earlier participants fell asleep was linked to about 1.3 pounds of weight loss, but the short study and some self-reported sleep measures limit what can be concluded.