If you are struggling to get to sleep at night, you may be in danger of diabetes and obesity, scientists say. Researchers at Brigham and Women's Hospital in Boston
found that people who slept for less than five hours a day had drastic change in their resting metabolic rates that can add 4.5 to 5.5 kg to their weight in a year.
In the long-run, this could lead to obesity and diabetes, the researchers said. "Within three or four years, you could be obese," Orfeu Buxton, a neuroscientist and sleep expert who led the study, was quoted as saying by Los Angeles Times. For their study, Buxton and colleagues placed 21 subjects in isolation for nearly six weeks.
For the three weeks before the experiment began, the volunteers were instructed to spend 10 hours in bed to ensure they got an optimal level of sleep. Then the subjects moved into dimly lit, isolated suites in the laboratory, where the research team removed "time cues" and otherwise disrupted the volunteers' sleep, allowing them only about five hours of per 28-hour period, scattered over various times of the day and the night.
They were not allowed any outside access. During the experiment and after a recovery period, Buxton and his team measured resting metabolic rates and insulin and glucose levels. It was found that on average, their pancreatic insulin secretion dropped about a third from where it should have been, increasing glucose levels after meals as a result.
Three subjects hit "clinically relevant" prediabetic glucose levels, Buxton said. The researchers observed an eight per cent decline in resting metabolic rate among the subjects when their sleep was bad. "That might sound like a small number, but it's enough where you would gain 10 to 12 pounds in a year," Buxton added.
Once allowed to sleep normally again for nine nights, the subjects recovered. The findings, published in journal Science Translational Medicine, have important ramifications for public health, Buxton said, adding the study could explain why night shift workers who struggle to sleep during the day are more prone to being overweight.