When I was little, my mother ‘tsk’ed me, saying that my eyes were bigger than my stomach. Turns out overeating does have something to do with what you see on the plate, or platter. But, essentially, it’s the result of a victory for the bad guys in a war between two groups of brain cells…
Chronic overeating can lead to obesity.
How often have you kept on eating even when you knew you should stop? It’s a family celebration, you reason. Or, It’s just SO darned good. Overeating may also be a result of having gone without food for an unusually long time.
Don’t blame yourself. Blame the little grey cells deep in your brain that regulate your eating behaviour.
Science steps in…
Researchers at the University of Michigan have discovered that your brain has two competing centres which receive signals from your body. One tells you to keep eating while the other tells you to stop eating.
The AgRP centre tells you to continue eating and the PMOC centre tells you when to stop; when you’re stomach is signalling it’s full. But when both centres are activated at the same time, the AgRP system overpowers the PMOC system and you continue to eat anyway. This usually happens when you are under stress or in an unusual situation, or when you are bombarded by sensory stimuli such as the enticing aromas and appearance of foods.
“Our work shows that the signals of satiety – of having had enough food – are not powerful enough to work against the strong drive to eat, which has strong evolutionary value,” Dr. Huda Akil, Lead Author of the study, says.
In their study using mice, the researchers discovered that giving overeating subjects the anti-overdose drug Naloxone immediately cut off overeating activity. So, the body’s natural opiate system is also involved. This was suspected from the outset of the study, since researchers already knew that the PMOC centre produces the natural opiate Beta-Endorphin, the body’s natural pain killer and ‘happy’ hormone. The AgRP centre also seems to activate the body’s opiate system.
The takeaway…
Further research may lead to the development of treatments for overeating, which is seen as a major contributor to the global obesity epidemic.
Other researchers are also looking at the PMOC/AgRP system as key to developing diet aids.
My take…
If research on the PMOC/AgRP systems can produce an aid to weight loss, it will certainly be welcomed by millions. With the constant hailstorm of Fast Food ads in all the media, and the weekly array of visual food porn otherwise known as supermarket flyers, we’re all prey to the urge to overeat.
“There’s a whole industry built on enticing you to eat, whether you need it or not, through visual cues, packaging, smells, emotional associations,” Akil says. “People get hungry just looking at them, and we need to study the neural signals involved in those attentional, perceptional mechanisms that drive us to eat.”
Even at this early stage, though, this line of research has given some of us a little peace of mind. We now know what kinds of temptations and stresses to avoid to help us avoid overeating.
~ Maggie J.