Losing a little sleep each night may not seem like a major health concern, but over time it could make you gain fat.
Research from Columbia University Vagelos College of Physicians and Surgeons found that adults who reduced their sleep by about 80 minutes per night for six weeks gained nearly one pound on average.
They also spent more time sitting and less time being physically active.
The findings add to a growing body of research suggesting that consistently getting enough sleep may help protect against weight gain and reduce the risk of obesity related health problems.
A Little Sleep Loss May Go a Long Way for Weight Gain
Earlier studies on sleep and obesity often focused on extreme sleep deprivation.
In many of those experiments, participants were limited to only about four hours of sleep per night.
Those studies showed that severe sleep loss can increase hunger, encourage overeating and contribute to weight gain.
However, sleeping only four hours a night is not a realistic pattern for most people to maintain for long periods.
The Columbia researchers wanted to examine a more common situation: people who regularly sleep less than they should — like six hours a night.
The study included 95 adults who normally slept between seven and eight hours each night.
During one six-week period, participants delayed their normal bedtime by about 90 minutes.
During another six-week period, they continued their usual sleep routine.
Researchers used wrist monitors to track sleep patterns and physical activity throughout the study.
They also measured body weight, waist size, body composition and hormone levels related to appetite.
After the period of reduced sleep, participants gained about one pound on average.
While that amount may sound small, researchers noted that the weight gain occurred after only six weeks.
If the same pattern continued over a year, the impact may start showing up in your waistline.
Less Sleep Was Linked to More Inactivity
During the sleep restriction phase, people spent about 17 additional minutes each day being sedentary.
Among men and postmenopausal women, the increase in inactivity was even greater, approaching 30 extra minutes per day.
The study found that the additional waking time didn’t translate into more movement. Instead, participants tended to spend more time sitting.
Excessive sitting can lead to the so-called sitting disease.
Sleep Loss May Affect More than Weight
The same group of participants has been involved in other research examining the effects of reduced sleep.
In one previous study, women with a higher risk of heart and metabolic disease who cut their sleep by about 80 minutes per night for six weeks developed increased insulin resistance — a precursor to type 2 diabetes.
Another study involving people with elevated heart disease risk found that mild sleep restriction increased inflammatory activity in the body.
Researchers say more studies are needed to fully understand how improving sleep habits affects long-term health.
