I learned a very important lesson at X-Weighted Connection, the all-day health/weight management workshop on Sunday, March 4, 2012 at Edmonton's Fantasyland Hotel, put together by Anaid Productions' Margaret Mardirossian.

(After producing five seasons of the popular Gemini award-winning X-Weighted reality show, after having a front-row seat on the enormous challenges some people face in losing weight, Margaret saw the dire public need to put together such workshops for those looking for answers and seeking a healthy lifestyle. Despite the show no longer being aired in Canada, Margaret put together the workshop, for Edmonton, Calgary and Winnipeg this year, as a public service.)

I'd always assumed obesity is far more about 'nurture' than 'nature', that extraordinary weight gain was simply the result of lack of discipline and bad eating habits. That you, dear chubby one, had just as much choice as the rest of us on your overweight condition, but you always chose to have that extra bag, or two, or three, of Doritos.

No, says lifestyle medicine practitioner Dr. David Macklin of Toronto, a family physician and one of Canada's leading experts on weight management, not at all.

"One of the biggest findings of recent neuroscience and obesity research," he said at the X-Weighted workshop, "is the discovery of the "reward" part of the brain. Going back to ancient times, evolution created a brain centre driven by the four basic survival behaviours of shelter, food, water and sex. We have our wants. When we have not had one for a long time, it feels really good to have it, and then we want to have some more. The reward brain has been hijacked by the proliferation of sugar, fat and salt foods, or hyper-palatable foods.

There's a hierarchy of substances that tickle the reward centre of the brain, "heroin, cocaine, crystal meth and crack," said Dr. Macklin. "But right under the opiates are potato chips, chocolate, ice cream and other hyper-palatable foods. Below them is smoking and alcohol. You don't take a drag of a cigarette and go into ecstasy, but a chocolate molten lava cake on vanilla ice cream ... which is more powerful?"

Equally as important as the reward part of the brain is the discovery of a definitive, DNA-located "reward sensitivity" to the reward brain that
varies in its intensity from person to person. In other words, it's actually part of our genetic code, a trait an individual has from birth on.

"There are people at the other end of the reward-sensitivity scale who can eat one bite of a chocolate chip cookie and stop ... aliens among us," jokes Dr. Macklin. "About 40 to 45% of the population does not have strong reward sensitivity. If they get a little overweight, they can lose the weight and not gain again.

"But for 400 years, we didn't know who was by nature sensitive and who wasn't. The hyper-palatable foods just weren't out there."

So what Dr. Macklin is saying is quite profound: That there actually is a scientific explanation for why some individuals are more prone to obesity than others, that it's not just a victimization stance, or a lack of eating discipline; that for some people, weight loss is a far harder row to hoe than others, that they can have a physical thing happening in their brains, a greater release of endomorphines triggering an addictive powerful pleasureable response, just a notch below drugs like heroin and cocaine.

lAt the very least, it's a nudge to be not so judgemental on the seriously overweight, as it gives serious credibility to the once poohed-poohed "they just can't help themselves."

At it's most impactful, Dr. Macklin can see the day when all children can be DNA tested at an early age for reward-sensitivity, and, if they have the trait, preventive treatment can kick in at a much earlier age, hopefully then helping down the line to never get fat.