November 7, 2012
Want To Sleep Better At Night? Shed Some Belly Fat
Lawrence LeBlond for redOrbit.com - Your Universe Online
Getting a good night's sleep is important to be healthy. However, a number of problems can prevent us from having a restful night. One such problem is being overweight or obese--an issue that has been studied immensely and closely linked to sleep deprivation.
Now, a team of researchers at Johns Hopkins University School of Medicine, has found that weight loss, whether it be from dietary changes or from diet and exercise, can improve the quality of sleep among overweight people.
“We found that improvement in sleep quality was significantly associated with overall weight loss, especially belly fat,” said senior study author Kerry Stewart, professor of medicine at the Johns Hopkins and director of clinical and research exercise physiology.
The findings of Stewart´s study was presented at the 2012 American Heart Association Scientific Sessions in Los Angeles.
For the study, the research team followed 77 overweight or obese individuals with Type 2 diabetes or pre-diabetes for six months. The study participants filled out sleep surveys at both the start and end of the study, detailing sleep problems such as sleep apnea, fatigue, insomnia, restless sleep, excessive sleep and use of sleeping aids. The team also measured body mass index (BMI) to track the volunteers´ changes in weight.
The participants were randomly assigned to one of two groups. One group followed a weight-loss diet with supervised exercise training, while the second group only had diet intervention. A total of 55 of the initial 77 volunteers completed all phases of the study.
At the end of the study period, both groups had experienced weight loss of 15 pounds on average and a 15 percent reduction in belly fat. Although a variety of sleep problems were reported by the participants, there was not one particular problem that was most prominent, so the team factored in a composite score, reflecting overall sleep. They found that both groups improved their overall sleep score by about 20 percent.
According to Stewart, belly fat is particularly concerning since it can be metabolically detrimental to health.
“Belly fat is almost like a living organ. It produces proteins that cause inflammation,” Stewart told Time's Alexandra Sifferlin in an interview. “When you lose a lot of belly fat in particular, the level of those substances go way down, and the inflammatory response is much less than it was before.”
That means heart disease rates decline as belly fat dissolves. The risk of heart disease is pronounced because of inflammation that aggravates the blood vessels. This inflammation also interferes with the body´s normal physiological processes, and in the end, leads to obesity that in turn puts added pressure on the heart and lungs.
“If you have a lot of belly fat, the lungs can´t expand as well, so it becomes harder to breathe when you´re sleeping, which is why more people get sleep apnea,” said Stewart. “When you have sleep apnea, you wake up more in the middle of the night, and that leads to daytime sleepiness and fatigue. So people are feeling miserable because they haven´t had a good night´s sleep.”
Shedding belly fat triggers a drop in inflammation and can lower insulin resistance and improve metabolism. “This can foster weight loss or prevent further weight gain,” explained Stewart.
It isn´t clear whether sleep problems cause obesity, or obesity causes sleep disturbances, although it is likely it is a combination of both processes. “We are not exactly sure where the problem starts, but we think it is a vicious cycle. Regardless of where it starts, they feed off each other,” concluded Stewart.