The study, published in Nature Clinical Practice Endocrinology & Metabolism (Vol. 2, pp. 447-458), has been picked up by many international news agencies, and keeps the food industry firmly in the cross hairs in the struggle against obesity.
The statements by Dr Robert Lustig from the University of California, San Francisco, has stoked the fires of the blame game by accusing western food manufacturing practices of creating a "toxic environment" that "dooms children to being overweight".
Obesity stats still on the rise
While the food industry has made efforts to cut fat content in some foods, remove trans-fats and offer healthy alternatives, obesity in children and adults is continuing to rise. The incidence of childhood obesity grew from 9,6 percent in 1995 to 13,7 percent in 2003 in the UK alone. In South Africa, 20% of children under the age of six are overweight.
"It will take acknowledgement of the concepts of biological susceptibility and societal accountability and de-emphasis of the concept of personal responsibility to make a difference in the lives of children," said Lustig.
Lustig said that it's well established that insulin acts on the brain to encourage eating through two separate mechanisms. Firstly, it blocks the signals that travel from the body's fat stores to the brain by suppressing the effectiveness of the hormone leptin, resulting in increased food intake and decreased activity. Secondly, insulin promotes the signal that seeks the reward of eating carried by the chemical dopamine, which makes a person want to eat to get the pleasurable dopamine 'rush'.
"Our current western food environment has become highly 'insulinogenic,' as demonstrated by its increased energy density, high-fat content, high glycaemic index, increased fructose composition, decreased fibre, and decreased dairy content," said Lustig.
"In particular, fructose (too much) and fibre (not enough) appear to be cornerstones of the obesity epidemic through their effects on insulin."
Changes in food processing
Lustig said that changes in food processing over the past 30 years, particularly the addition of sugar to a wide variety of foods that once never included sugar and the removal of fibre, both of which promote insulin production, have created an environment in which foods are essentially addictive.
Lustig also dismissed claims by some that, when it comes to children, individuals choose what to eat: "Young children are not responsible for food choices at home or at school, and it can hardly be said that preschool children, in whom obesity is rampant, are in a position to accept personal responsibility," said Lustig.
"If we don't fix this, our children will continue to lose," he said.
Professor Michael Lean, holder of the Rank Chair of Human Nutrition at the University of Glasgow, told FoodNavigator.com that the concept of the "toxic environment" was not new, but agreed that the food industry must display "corporate social responsibility" when it comes to the obesity issue.
Two factors at play
Professor Lean told FoodNavigator.com that obesity is due to two things - the amount of fat as a proportion of calories consumed, and the level of physical activity. Lean also said that consumers do not generally make food choices that are informed by nutritional knowledge.
"It is an inescapable truth that food is responsible for the obesity epidemic in connection with physical activity," said Professor Lean.
Offering a different perspective, a recent report from the UK-based Ethical Investment Research Services (EIRIS) said that the food industry was not to blame for customers' weight problems. However, the report said that the industry must accept that significant damage will be done if it is not seen to be responding to the problem.
"Our research revealed little evidence of obesity-related improvement targets and key performance indicators from the multi-national food and beverage firms we analysed," said report author and EIRIS research analyst Heleen Bulckens.
"Food and drink producers are waking up to the business risks associated with obesity, but significant challenges remain." - (Decision News Media, August 2006)
SA snack tax urged to fight obesity
Strategies to combat obesity