According to a new study, sleep restriction causes people to gain weight even when their appetite, food cravings and food consumption decreases.
Making a presentation on the study at the 23rd Annual Meeting of the Associated Professional Sleep Societies, University of South Australia researcher Dr. Siobhan Banks said that the findings suggested that energy intake exceeded energy expenditure during the sleep restriction.
The study involved 92 healthy individuals (52 male) between the ages of 22 and 45 years who participated in laboratory controlled sleep restriction. Subjects underwent two nights of baseline sleep (10 hours in bed per night), five nights of sleep restriction and varying recovery for four nights. Nine well rested participants served as controls.
The researchers found that the people whose sleep was restricted experienced an average weight gain of 1.31 kilograms over the 11 days of the study.
Among the subjects with restricted sleep, who reported a change in their appetite and food consumption, more than 70 percent said that it decreased by day 5 of the study.
A group of well-rested control subjects did not experience the weight gain.
Banks, a former assistant research professor at the University of Pennsylvania School of Medicine, said that it was surprising that participants did not crave foods rich in carbohydrates after sleep restriction, as previous research suggested they might.
The study's findings suggest that even though physiologically the desire to eat was not increased by sleep loss in participants, other factors such as the sedentary environment of the laboratory and the ability to snack for longer due to reduction in time spent asleep might have influenced the weight gain.
"During real-world periods of sleep restriction (say during shift work), people should plan their calorie intake over the time they will be awake, eating small, healthy meals. Additionally, healthy low fat/sugar snacks should be available so the temptation to eat comfort foods is reduced. Finally, keeping up regular exercise is just as important as what food you eat, so even though people may eel tried, exercising will help regulate energy intake balance," said Banks.