Eating too much high-fat and high-sugar food is bad for everyone, but under stress, it can lead to much more weight gain than in normal situations, according to a new study.
A team led by Professor Herbert Herzog, who is the head of the Eating Disorders laboratory at the Garvan Institute of Medical Research, did experiments on mice.
They discovered that a high-calorie diet when combined with stress, resulted in more weight gain than the same diet caused in a stress-free environment.
A mouse in a lab Source: AAP
“We have uncovered a previously unknown pathway in the brain that specifically activated under stress conditions when it’s combined with a high-calorie intake,” Dr Herzog told SBS News.
The researchers discovered that at the heart of this weight gain was a molecule called neuropeptide Y, or NYP, which the brain produces in response to stress to stimulate eating.
Pathways in the brain
To understand what controls this stress eating, the Garvan scientists looked at different areas of the brain.
While food intake is mainly controlled by a part of the brain called the hypothalamus, another part of the brain, the amygdala, processes emotional responses, including stress and anxiety.
Professor Herzog explained that under chronic stress “the amygdala also gets activated”.
nerve cell in the nuclei of the amygdala (ceM), which produce the molecule NYP (red) in response to stress. Source: Garvan Institute
“If you combine it with a high-calorie diet, this drives additional food intake”, he said.
The scientists discovered that when they switched off the production of the neuropeptide Y in the amygdala, weight gain was reduced.
This shows a clear link between stress, obesity and neuropeptide Y, the scientists said.
Professor Herzog said the study highlights that people need to be even “more conscious about what their diet is if they are exposed to continuous stress”.
Professor Herbert Herzog and Dr Kenny Chi Kin Ip from the Garvan Institute Source: Supplied
That includes plenty of fresh food and vegetable and lean protein.
'A fascinating study'
Professor John Dixon, the head of Clinical Obesity Research at the Baker Heart and Diabetes Institute, and a leading global expert in obesity commends the study.
“It’s a fascinating study, it's one of many discoveries that has really improved our knowledge of the neurobiology of obesity,” he told SBS News.
“We now respect that obesity is really a disease related to the way the brain has been set up and wired from early life.
“We’ve known for a long time that stress drives eating, it drives overweight, and in particular that our severely obese people are often stressed by obesity stigma, obesity discrimination, ” Professor Dixon added.
Obesity Source: AAP
He noted that often leads to a vicious cycle of more stress, more overeating and therefore more stigma.
