Prolonged Sleep Restriction May Increase Body Weight

In a pooled analysis of two randomized crossover trials, reducing nightly sleep by about 1.5 hours for 6 weeks was associated with modest increases in body weight and waist circumference without measurable changes in body composition.

By
Andrea Surnit
July 9, 2026
3 min

MDSpire News

Overview

A pooled analysis of two randomized crossover trials indicates that reducing sleep by approximately 1.5 hours nightly for six weeks may lead to modest weight gain in adults at elevated cardiometabolic risk. The study found an average increase of 0.45 kg in body weight and changes in waist circumference and body volume during the sleep restriction period.

Background

Sleep duration is a critical factor influencing health and metabolic processes. Insufficient sleep has been linked to obesity and other cardiometabolic risks.

Data Highlights

Outcome	Change
Body Weight	+0.45 kg
Waist Circumference	+0.52 cm
Whole-body Volume	+0.56 L
Fasting Leptin Concentrations	Increased
Sedentary Behavior	+17 minutes/day

Key Findings

Sleep restriction reduced nightly sleep duration by an average of 78 minutes.
Participants experienced a mean weight gain of 0.45 kg during the sleep restriction period.
Waist circumference increased by 0.52 cm and whole-body volume by 0.56 L with sleep restriction.
Higher fasting leptin concentrations were observed during the sleep restriction phase.
Participants engaged in 17 more minutes of sedentary behavior per day during sleep restriction.
No significant differences were found in body composition metrics or appetite-related hormones aside from leptin.

Clinical Implications

Clinicians should consider the impact of sleep duration on weight management, particularly in patients with elevated cardiometabolic risk. Monitoring sleep patterns may be a valuable component of comprehensive obesity care.