By KHT Staff
KAOHSIUNG — Three nights of recovery sleep did not immediately reverse an increase in visceral fat among participants in a small inpatient study on sleep restriction, according to research cited this week by a Kaohsiung doctor.
The 2022 study, published in the Journal of the American College of Cardiology, involved 12 healthy adults aged 19 to 39 who were not obese.
Each participant completed two 21-day inpatient sessions. After an initial four-day period in which they were allowed nine hours in bed each night, participants spent two weeks following either a normal nine-hour sleep schedule or a restricted schedule allowing only four hours in bed.
Both groups were then allowed nine hours in bed for three nights of recovery sleep.
Compared with the normal-sleep period, the restricted schedule was associated with a 9% increase in total abdominal fat area and an 11% increase in visceral fat, which accumulates around internal organs. The difference in body weight was comparatively small, at about 0.5 kilograms.
Participants’ calorie consumption and weight began returning toward their previous levels during the recovery period, but their visceral fat continued to increase. The researchers said the results suggest that catch-up sleep may not immediately reverse fat accumulation caused by an extended period of inadequate sleep.
Fan Yaxuan (范亞萱), a family medicine physician at Genesis Clinic in Kaohsiung, told TVBS that insufficient sleep can affect areas of the brain involved in appetite and reward, making foods high in fat and sugar more appealing.
Fan said a 15- to 30-minute nap may help restore alertness after a poor night’s sleep but cannot replace adequate and regular nighttime sleep.
She cautioned that the findings do not mean a single late night will inevitably cause weight gain. The greater concern is making insufficient sleep a long-term habit.
The researchers also warned against applying the results too broadly. The experiment included only 12 young, healthy participants, and further research would be needed to determine whether people who are older, obese, or living with metabolic conditions respond in the same way.
Sources: TVBS; Journal of the American College of Cardiology
