Food-addiction blamed for obesity

Jan 13 2009

A study by scientists in New Zealand say craving something sweet like a biscuit or piece of chocolate could be a response to an addiction.

According to Dr. Simon Thornley from Auckland's Regional Public Health Service the reason unhealthy sugar and fat laden foods are being consumed is because they are addictive and could be behind the increase in obesity.

He says foods such as cornflakes, biscuits and soft drinks may be as addictive as cigarettes, as heavily processed foods with a high glycaemic index (GI) trigger an addictive sugar rush that can be hard to resist and leads to obesity.

Science has grouped food types by using a glycaemic index - high GI foods are typically cakes, biscuits, juices and processed fast food such as hot chips - low GI foods include wholegrain breads, most fruit and vegetables and foods low in carbohydrates such as lean meat, fish and nuts.

Dr. Thornley says the key component of those foods which may predict their addictive potential is the glycaemic index or how fast they deliver a sugary hit and foods with a high GI cause blood-sugar levels to spike suddenly, and this sugar rush stimulates the same areas of the brain associated with addiction to nicotine and other drugs.

Low-GI foods produce gradual rises in blood sugar and insulin levels, and a feeling of contentment and satiety and he believes his food addiction theory, if proven, has important public health implications.

He says when it comes to food, the food environment seems to determine people's ability to eat and if sugary foods are around they seem to be eaten more frequently.

Dr. Thornley says studies of nicotine withdrawal have been carried out and similar studies, testing various withdrawal symptoms such as difficulty concentrating, irritability, craving, urges to eat, need to be done with food as he says there is evidence that people who binge on 'high-carb' foods experience symptoms of addiction - loss of control, a compulsion to keep taking higher amounts to get the same buzz - and suffered withdrawal if they went cold turkey.

Such symptoms are usually associated with addictions to cocaine and alcohol.

Research has also found that people with a higher body mass index have fewer brain pleasure receptors but experts say how the brain handles drugs such as nicotine and how the brain handles nutrients such as glucose are very different and they do not agree that addictive behaviour and eating are linked and labelling obesity an addiction was "far-fetched".

They say this does not explain the rise of obesity and other factors are involved - this is however the first time GI has been implicated as the predictor of the addictive potential of foods.

The study is published in the journal Medical Hypotheses.