Food images cause a spike in brain activity, but less so at
night.
After gobbling the fourth Oreo in a row while bathed in
refrigerator light, have you ever thought, "That wasn't enough," and
then proceeded to search for something more?
Researchers
at BYU have shed new light on why you, your friends, neighbors and most everyone
you know tend to snack at night: some areas of the brain don't get the same
"food high" in the evening.
In
a newly published study, exercise sciences professors and a neuroscientist at
BYU used MRI to measure how people's brains respond to high- and low-calorie
food images at different times of the day. The results showed that images of
food, especially high-calorie food, can generate spikes in brain activity, but
those neural responses are lower in the evening.
The
study, which appears in academic journal Brain Imaging and
Behavior, also reports that participants were subjectively more
preoccupied with food at night even though their hunger and
"fullness" levels were similar to other times of the day.
Masterson,
who carried out the research for his master's thesis under faculty advisor
James LeCheminant, said the intent was to better understand if time of day
influences neural responses to pictures of food.
The
researchers teamed up with BYU neuroscientist Brock Kirwan to use functional
MRI to monitor the brain activity of study subjects while they viewed images of
food. The participants viewed 360 images during two separate sessions held one
week apart--one during morning hours and one during evening hours.
Subjects
looked at images of both low-calorie foods (vegetables, fruits, fish, grains)
and high-calorie foods (candy, baked goods, ice cream, fast food). As expected,
the researchers found greater neural responses to images of high-calorie foods.
However, they were surprised to see lower reward-related brain reactivity to
the food images in the evening.
"We
thought the responses would be greater at night because we tend to over-consume
later in the day," said study coauthor Lance Davidson, a professor of
exercise sciences. "But just to know that the brain responds differently
at different times of day could have implications for eating."
Nevertheless,
researchers noted that the study is preliminary and additional work is needed
to verify and better understand the findings. The next research steps would be
to determine the extent that these neural responses translate into eating
behavior and the implications for weight management.
Masterson,
who is heading to Penn State University to work on his PhD in the fall, said
the study has helped him pay better attention to how food makes him feel both
in the morning and the evening. And as for his late-night eating habits?
"I
tell myself, this isn't probably as satisfying as it should be," he said.
"It helps me avoid snacking too much at night."
Story Source:
The
above story is based on materials provided
by Brigham Young
University. Note: Materials
may be edited for content and length.
Journal Reference:
Travis D. Masterson, C. Brock Kirwan, Lance E. Davidson, James
D. LeCheminant. Neural reactivity
to visual food stimuli is reduced in some areas of the brain during evening
hours compared to morning hours: an fMRI study in women. Brain Imaging and Behavior, 2015; DOI:10.1007/s11682-015-9366-8
Cite This Page:
Brigham Young University. "Late-night snacking: Is it your
brain's fault?." Science Daily,
5 May 2015. <www.sciencedaily.com/releases/2015/05/150505121418.htm>.