Sleeping too little makes you gain weight, writes focus.it.
According to a new study, 80 minutes less sleep per night for six weeks is enough to make us gain almost a kilogram.
It may not seem like much, but when multiplied by the number of “short” nights in an entire year, and by the number of people who are subjected to this chronic sleep deprivation, the problem takes on considerable significance.
One closer to reality
Sleep deprivation studies often subject subjects to significant reductions in nightly sleep for short periods of time (for example, allowing them to sleep only four hours a night.
However, most people cannot tolerate such drastic sleep cuts for long.
So researchers at Columbia University Irving Medical Center developed a more realistic experimental design, involving people with moderate sleep deprivation who sleep 5 or 6 hours a night.
To simulate this condition, which affects approximately 30% of the adult population, scientists asked 95 adult participants who typically slept 7-8 hours a night to delay bedtime by 90 minutes for six weeks and then maintain their normal sleep schedules for the following six weeks.
They then compared various metabolic parameters (activity levels during the day, changes in body weight, waist circumference, body composition, and fasting hormone levels) between each period.
More tired, less active
During the sleep-deprived phase, sitting time in the group increased by an average of 17 minutes; for postmenopausal women and men, it increased by an average of 30 minutes.
At the same time, a weight gain of approximately 450 grams occurred. The reasons for the link between poor sleep and weight gain have not been explored, but previous studies by the same group have found two possible “clues” as to why.
Women at higher than normal cardiometabolic risk who sleep 80 minutes less per night for six weeks experience increased insulin resistance, poorer cellular sensitivity to insulin, a precursor to type 2 diabetes; and after mild sleep restriction, high-cardiac risk patients experience an influx of inflammatory cells into the heart.
Overall, evidence of a link between moderate but sustained sleep restriction and obesity-related conditions and metabolic problems is growing.
