Aussie researchers find link between obesity and the size of your brain

In world-leading research, Australian scientists have traced the root cause of obesity back to a most surprising cause.

You could be fat simply because of the size of your brain.

That’s the finding from a major study led by Australian researchers into obesity and its links to our brains.

Aussie scientists have found that in adolescents in particular, those with a larger nucleus accumbens — also known as the pleasure centre in the brain — had a higher percentage of body fat.

It was up 3 per cent on those with a smaller sized nucleus accumbens.

The researchers also found body fat is linked to the size of the medial orbitofrontal cortex — a region at the front of the brain that is involved in reward processing of food cues.

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The lin between brain size and body size was particularly apparent in adolescents, the researchers said.

The study examined the association between body fat, impulsivity and brain structure in 127 people across the body mass index (BMI) spectrum.

The work was led by Dr Naomi Kakoschke from the Monash Institute of Cognitive and Clinical Neurosciences and will today be published in the international journal Nature Scientific Reports.

In addition to the finding on the nucleus accumbens the volume of an individual’s left medial orbitofrontal cortex was also positively associated with an increase in body fat due to the role it plays in reward and emotion processing.

Obesity is on the rise in Australia and experts are concerned about how to get a hold on it.

Today’s research may help us understand why for some people it is harder to lose and keep weight off.

“We know that excessive body fat accumulation increases the risk of developing chronic health conditions including cardiovascular disease, Type 2 diabetes and dementia, but we need to look at how the workings of our brain play a part in this body fat gain,” Dr Kakoschke said.

“Studies have repeatedly shown that reward sensitivity is elevated in people with obesity, particularly for those with binge eating disorder.”

Obesity: a growing problem.

Two in three Australians are considered overweight or obese and Australia is the fifth most obese nation in the world according to the OECD.

One in four Australian children aged 2-17 were considered overweight or obese in Australia in 2014-15.

Executive Manager of the Obesity Policy Coalition Jane Martin said the research gave some good insights into how the brain was linked to unhealthy eating behaviours and the development of obesity.

She said more action was needed to tackle obesity in Australia.

“The development of a national obesity strategy provides an opportunity to develop policies to protect children from junk food marketing, place a levy on sugary drinks and ensure that health star labelling system is used on all packaged foods to help people make better choices,” Ms Martin said.

Australian Medical Association President Tony Bartone said the research highlighted the “multi-factorial” links associated with obesity.

“It does lend weight to the fact that obesity is not purely about voluntary decisions and there are biological factors that push you in one direction or the other,” Dr Bartone said.

He said tackling obesity should be a key national focus.

“We know the impact upon the public purse is increasing significantly and will escalate rapidly over coming years without significant change,” Dr Bartone said.

“And we are looking at the first generation of children whose life expectancy is significantly less than their parents for the first time in more than a century.”

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Originally published as Aussie researchers find link between obesity and the size of your brain