Food addiction should be recognised as a medical condition so obese people can get help to quit, the National Addiction Centre director says.
Almost a third of the population could be addicted to food - yet struggling addicts received no support or funding, unlike people at the other end of the spectrum who received help for eating disorders such as anorexia, Professor Doug Sellman said.
He will today address an Australasian psychiatry conference in Wellington on research into food addiction.
The symptoms were similar to those in drug and alcohol addicts, he told The Dominion Post.
"Like people with methamphetamine, you don't get the shaking, but it's the craving, feeling deprived and really needing it.
"It's like they need those particular foods as if their lives depended on it. But they don't; they've got their wires crossed.
"The thing with an addiction is whatever self-control you had at the beginning is eroded by the forming of the addiction.
"It's a neurological thing."
The National Addiction Centre is halfway through a five-year study of 25 people hoping to beat obesity.
Prof Sellman said the participants in the study often failed to control their cravings and if they tried to ditch one of their fixes they would crack.
"They seem to go into a regressed state and really feel deprived, intensely.
"It's like a primitive anger."
The need for food "hijacks" the brain's limbic system, which is responsible for the body's survival instincts - in effect, the brain tricks the body into needing more and more food.
Like drug addictions, people addicted to food needed increasingly large "hits" to get their daily fix. "Even though they know it's bad for them they still just feel this drive to eat."
Health Ministry figures show 34.1 per cent of Kiwis are classified as being of normal weight, 37 per cent are overweight and 27.8 per cent obese.
New Zealand was regarded as the second-most overweight country in the world, behind the United States and narrowly ahead of Australia, Prof Sellman said.
"We are in the midst of an advancing obesity epidemic.
"It's our whole style of life.
"We've become inactive . . . and we are surrounded by treat-food and alcohol," he said.
"The only effective way for an individual [to conquer their addiction] now is surgery. But that would bankrupt the country - we don't have the money to give everyone a new stomach."
He said the Government needed to do more to combat obesity.
Associate Health Minister Tariana Turia, who underwent bariatric surgery in 2009, agreed.
"I certainly was addicted.
"No matter how much I would try to diet, it was difficult for me to shift that weight."
Mrs Turia no longer suffered from diabetes, blood pressure problems or asthma since the surgery.
An Overeaters Anonymous spokeswoman said the draw of food was irresistible.
"There's not a lot of understanding out there.
"People see an overweight person and just think: they're weak-willed or they just need to try harder but it's not like that.
"For us, it's exactly the same as drug and alcohol addiction. Once you start you can't stop, you just keep eating and eating. It's not just a physical problem, it's mental."
TOP 10 COMMON ADDICTIVE FOODS
- © Fairfax NZ News
How diligent are you when it comes to sorting roadside recycling?Related story: City recycling a juggling act for council