Spare a thought for Jamie Oliver. There he is, standing at the foot of the Everest that is American obesity, trying to persuade a nation reared on deep-fried instant gratification to start eating its greens, and all he gets for his trouble is grief.
Our hero is currently to be seen on US network television trying to persuade the schoolchildren in Huntingdon, West Virginia to adopt a healthier diet, in a reprise of Jamie’s School Dinners (which was so successful over here that, according to a recent study, the campaign improved SAT results by 4.5 per cent in the schools where the scheme was first tried). The result Stateside is a mickey-take from David Letterman and a rebuke from a DJ in the rust belt town who has told the meddling Brit to stop infringing the right of freedom-loving Americans to eat themselves to death.
Listen to David Kessler and you will learn that Oliver is up against much more than cultural resistance. The former head of the United States Food and Drug Administration is in London promoting his book. In it he describes how our exploding waistlines (on current trends 40 per cent of Britons will be obese by 2025) are due to something much more sinister than greed and the development of the TV remote control.
The food we eat, or rather the ubiquitous, processed, ready-made, fast food we eat, is not really food at all, he says. It’s a drug, in its own way as addictive as cocaine.
The three bogeymen Kessler identifies are sugar, fat and salt. Pump the right combination of those ingredients into a dish and you have a winner. The result is something called hyperpalatable food, like a Burger King bacon double-cheese burger or a McDonald’s flavoured milkshake. These foods produce increased levels of the neurotransmitter dopamine, which, among other functions, produces in us a sense of reward.
When eating your favourite naughty food you reach what Kessler terms the Bliss Point, that moment during which the cares of the world are banished and replaced by the pure, focused experience of eating. Such foods slip down easily and comfortingly, being “pre-masticated”. The roast we used to have to chew 25 times per mouthful has been replaced by processed meat that goes down in 10 chews. It is, in effect, adult baby food.
The brain clocks the pleasure created by the burger and proceeds to build around it a memory, which in turn creates a powerful sense of anticipation, leading to repeat behaviour.
The neurological stimulus drives us to eat long after our calorific and nutritional needs have been satisfied.
Not just greed
Old-fashioned hunger simply doesn’t come into it. And neither does greed, in the traditional sense of the word.
“We are all wired to be focused on the most salient stimuli around us – like alcohol, tobacco, sex, gambling,” says Kessler. “And what is the most socially acceptable stimulus? Food.
“The basis of the modern food industry is to take fat, sugar and salt and put it on every corner of every street and make it into entertainment. It captures the neural circuits and hijacks the brain. We develop habits around our favourite foods and become aroused when we anticipate them. A pattern develops: cue-activation-arousal-reward. The circuits involved – memory, learning, motivation, habit – are those affected by addictive substances or activities.
Sugar and fat
Kessler cites the work of Adam Drewnowski, of the University of Washington, who has studied human taste and dietary choices for 30 years. Drewnowski initially focused on sugar but soon realised that it alone was not the reason why humans are partial to sweetness – if it was, we would simply open a packet of sugar and eat it.
The crucial factor was the combination of sugar and fat. In an experiment he added various amounts of sugar to five different dairy products. Asked to choose which foods they liked best, the subjects awarded low marks to products containing sweetened skimmed milk (lots of sugar, little fat) and to unsweetened cream (lots of fat, little sugar). When the same amount of sugar was mixed into low-fat and high-fat products, however, people invariably preferred higher-fat combinations.
Kessler, a paediatrician and former dean of the medical school at Yale University, says the food industry has optimised its products over the past three or four decades. “They learned to do it by trial and error. They understood that fat, sugar and salt stimulated. They looked at where the long queues were. They designed bliss into the food.
So what is to be done?
“You have to change the culture. You have to change the way we look at food in the same way that we successfully changed the way we look at tobacco. Eating, he says, needs to return to the structured habits of the past, with set meals and smaller portions. We have to do something, or else face the prospect of millions more children suffering from Type 2 diabetes.
“You know that image of the kid saying ‘mommy, daddy, please don’t smoke’? We have to get to the point where the kid says ‘mommy, daddy, please don’t take me to that fast-food restaurant’.”
It will be a long journey, admits Kessler.