June 18, 2013
Less Sleep Leads To Obesity
Michael Harper for redOrbit.com — Your Universe Online
Researchers, scientists and other medical professionals from all over have descended upon San Francisco this week for the Endocrine Society´s 95th Annual Meeting. Here they are discussing their latest studies involving diabetes, obesity and how particular diets can affect the body.
For instance, researchers from the University of Chicago´s Section of Endocrinology shared results of a study on Monday which found people who don´t get enough sleep at night are more likely to get the munchies and end up overeating. This, in turn, could lead to obesity and further sleep issues, creating a downward spiral of negative health effects. Previous studies have already found that not only does obesity cause sleeping problems, but that those who cannot sleep tend to eat more bad foods late at night.
Erin Hanlon, PhD and research associate at the University of Chicago led the study which found when young, healthy adults get less sleep, around 4.5 hours a night, they are more likely to feel hungry throughout the day and possibly overeat.
“Past experimental studies show that sleep restriction increases hunger and appetite,” Hanlon said in a recent statement.
She blames an increase in a molecule called 2-arachidonoylglycerol, or 2-AG, for this overeating.
In her study, Hanlon observed nine volunteers, each with an average age of 23-years old. These participants spent six nights in a sleep lab, then spent another six nights there about a month later. They were allowed to sleep for randomly assigned times, either from 11 pm to 7:30 am (or a normal eight and a half hours) or from 1 am to 5:30 am, or a partial night´s sleep at 4 and a half hours. The researchers then gave them a measured diet based on their height and weight.
Following the second night of either 8.5 or 4.5 hours of sleep, Hanlon and team took blood samples every hour for a 24 hour period. They then looked for the 2-AG molecule in each of these samples. This molecule is linked to the amount of enjoyment one receives as they eat, so if a person has high amounts of 2-AG in their blood, they´re less likely to enjoy their food and may not feel full or satisfied after eating a full meal. This molecule works much in the same way as cannabinoids do in marijuana.
Hanlon and team found that 2-AG levels were lowest in the middle of the sleep cycle and highest in the afternoon when the body needs to enjoy the intake of food. Those who had only slept for four and a half hours the night before the blood tests, however, had higher peaks of 2-AG levels than those who slept for a solid eight hours.
This means those who don´t get enough sleep at night may be more likely to overeat the next day because their bodies won´t feel as full or as satisfied than if they had slept an appropriate amount of time.
“These findings are highly relevant to millions of individuals who are at an increased risk of obesity and its health consequences because of chronic short sleep or sleep disruption,” said Hanlon in closing.
This study adds even more proof that managing obesity and maintaining a healthy diet goes beyond watching what you eat, but also includes the other choices while awake, such as exercise and the amount of sleep received at night.