Brain’s off-switch to control overeating, obesity linked to OGT enzyme: Study

By Steve Pak / 1458363821
(Photo : Facebook) A new study shows that a certain brain enzyme can switch on/off appetite, which can affect over-eating and obesity

Dieters who have trouble cutting calories and burning fat will be pleased to learn that scientists have reportedly found the brain's on/off switch that controls appetite. This could make it easier for people to avoid over-eating and obesity. When researchers turned off a certain enzyme in mice's brains they ate twice as much food during meal times and their body fat tripled in just three weeks.

The study was published March 17, Thursday in Science. It was conducted by a research team from John Hopkins University (JHU) School of Medicine that was led by Richard Huganir.    

During the study when researchers switched the enzyme back on the rodents halved their food intake and lost weight just as quickly, according to Ars Technica. These findings suggest that new drugs could be developed to treat human obesity.  

The enzyme that controls how much food people eat is called O-GlcNAc transferase (OGT). It functions in a chemical pathway controlled by nutrients and different metabolic hormones such as insulin.

Scientists linked the pathway to obesity a long time ago, but did not know how it was connected to the metabolic problem or OGT's job in the process.

JHU researchers tried to solve the mystery by first using a genetic tool to delete the OGT enzyme from the adult mice's CPUs. They soon noticed a big shift in the eating habits of the small rodents.

The genetically modified (GM) mice then gobbled up double the amount of food the regular mice ate during each meal. However, the control and experimental groups both ate about the same number of meals per day.

The OGT-lacking mice became bigger as their body fat tripled and their lean mass had no gain. Meanwhile, the non-genetically engineered mice ate a regular amount of food and stayed at a healthy weight.

Researchers learned that removing the OGT enzyme in the mice's heads affected the brain region called hypothalamic paraventricular nucleus (PVN). In non-GM mice the PVN's nerve cells lit up after they ate a big meal, but did not in the OGT-missing mice.

In related news a new study shows that about half of Buddhist monks in Thailand are obese, according to Time. The Thai government spent more than $8.5 million on their medical expenses during 2012 alone.

Here are some ways to control appetite: