Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite.
Level 2 - randomized trial
Individual randomized crossover clinical trial
PubMed 15583226 · doi:10.7326/0003-4819-141-11-200412070-00008
What was done
In a randomized, two-period, two-condition crossover study at the University of Chicago, 12 healthy young men (mean age 22 ± 2 years, mean BMI 23.6 ± 2.0 kg/m²) underwent 2 days of sleep restriction and 2 days of sleep extension under controlled conditions of caloric intake and physical activity. Researchers measured daytime profiles of plasma leptin and ghrelin alongside subjective ratings of hunger and appetite.
What was found
Compared to sleep extension, sleep restriction resulted in: - An 18% reduction in mean plasma leptin levels (P = 0.04) - A 28% increase in mean plasma ghrelin levels (P < 0.04) - A 24% increase in subjective hunger ratings (P < 0.01) - A 23% increase in overall appetite ratings (P = 0.01), specifically for calorie-dense foods with high carbohydrate content (increase of 33% to 45%; P = 0.02)
Why it matters
This study provides mechanistic, experimental evidence that acute sleep loss directly alters peripheral appetite-regulating hormones, promoting hunger and cravings for calorie-dense foods.
Limits
The study had a very small sample size of only 12 healthy young men, limiting generalizability to women, older populations, and clinical cohorts. It assessed only acute (2-day) sleep restriction, and energy expenditure was not measured.
Cited by
- supports Prior studies on sleep restriction have demonstrated a reduction in the satiety hormone leptin.