New research carried out in the US has highlighted a link
between high-fat diets and individuals suffering from higher levels
of sleep fragmentation.
According to the study from the University of Minnesota and
Veterans Affairs Medical Center - that is set to be published at
this year's Annual Meeting of the Society for the Study of
Ingestive Behavior - prolonged exposure to a high-fat diet has a
significant impact on the ability of animals to achieve a restful
night's sleep, something mirrored in humans.
The research focussed on rats, but scientists believe there could
be a considerable correlation between their findings in the animal
world and the human population, with sleep a basic function of
Scientists based their observations on a 24-hour sleep-wake cycle,
noting when the subjects would sleep and be active in order to
ascertain a better understanding of the impact of diet on their
As such, the study showed that in those animals that were fed a
high-fat diet for a prolonged period, the subject did not sleep
soundly during the night in comparison with subjects fed a
standard, balanced selection of foods.
Furthermore, the rats who suffered from sleep loss during the
night were more lethargic and prone to sleeping during periods when
their healthy counterparts were alert and awake.
Catherine Kotz, lead author of the report, commented: "Studies in
humans indicate a relationship between sleep quality and obesity.
Our previous work in animals shows a link between good-quality
sleep, resistance to weight gain and increased sensitivity to
orexin, a brain chemical important in stabilising sleep and wake
"The current studies show that after high-fat diet-induced weight
gain in rats, sleep quality is poor and orexin sensitivity is
decreased. These findings suggest that poor sleep associated with
weight gain due to a high-fat diet may be a consequence of reduced
As a result, the issue of the impact of weight gain on sleep
quality remains a key concern for researchers, and with more people
suffering from obesity in societies around the world each year, it
is one area of study where greater understanding would provide
significant social benefits in the future.
Indeed, there are numerous sleep-related conditions that can
affect obesity sufferers, such as sleep apnoea, but what this study
shows is that as levels of orexin in the brain diminish, this may
be a trigger for further weight gain in what is essentially a
vicious circle for sufferers unless they can remedy their sleep
Meanwhile, two studies were presented at last month's Sleep 2012
conference in Boston highlighting how sleep deprivation can result
in people making poor food choices, as their body craves unhealthy
According to the study led by Columbia University in New York,
those individuals who suffered from greater amounts of sleep
deprivation saw parts of their brain impaired that would normally
regulate hunger and food selection and accordingly, this meant
people were more prone to crave those foodstuffs that are deemed
"The results suggest that, under restricted sleep, individuals
will find unhealthy foods highly salient and rewarding, which may
lead to greater consumption of those foods," said the university's
Dr Marie-Pierre St-Onge.
Led by Stephanie Greer of the University of California, the second
study also focused on the ability of sleep impaired individuals to
make sensible food choices and asked participants to rate 80
foodstuffs in terms of their level of attractiveness following a
night of sound sleep and also one of sleep deprivation.
The results showed that under sleep-deprived conditions, the
frontal lobe of the brain appeared to function less efficiently,
with the study delivering a corresponding result to that carried
out by the researchers in Columbia.
Posted by Elizabeth Mewes