Report – Why we can’t eat just one
Eating addictive fast food is not just about hunger or taste, it is a complex process which is set about by the brain which anticipates the stimulus of having something which pleases the senses. Flavour, fat, salt and sugar makes fast food the equivalent of adult ‘baby food’, something that is eaten more for stimulation than for nutrition or because of actual need
When you look at a huge plate of pakoras or salted potato chips, do you feel that if you start eating them, you won’t stop until you’ve wolfed them all down. Yes, all of us struggle to eat well when it comes to junk food.
In his new best-selling book, “The End of Overeating: Taking Control of the Insatiable American Appetite,” Dr David Kessler, a US-based San Francisco Bay Area pediatrician, explains why certain foods loaded with fat, sugar and salt exert such a pull, despite our best intentions to avoid them. As he discusses the biology that leads to devouring a plate of fries, he delves into such puzzles as why the French fry binger is more likely to remember the pleasant stimulation of the fries’ salt, fat, texture and flavour than the stomach ache and gastric trouble that follow it.
What do you think is the biggest misconception about why people overeat? That it’s a matter of willpower, that you can just use self-control, but one needs to delve a little deeper into what is going on in the brain when you start thinking about a very desirable food, like a potato chip or a chocolate-chip cookie?
The power of food comes not only from its taste but from that anticipation. That anticipation is based on prior experience, learning and memory. Something’s going to set off that anticipation, those thoughts of wanting. So whenever you are near your favourite fast food joint or ice-cream parlour, the place and the sense of anticipation grabs your attention. It occupies our working memory. Our brains get activated.
Twenty years ago the average chews per bite was about 20, now it’s two or three. The food goes down in a whoosh and it’s very stimulating.
What happens once you start eating?
In people who have a hard time controlling their eating, their brain circuits remain elevated and activated until all the food is gone. Then the next time you get cued, you do it again. Every time you engage in this cycle you strengthen the neural circuits. The anticipation gets strengthened. It’s in part because of ambivalence. Do you ever have an internal dialogue? “That would taste great. No, I shouldn’t have it. I really want that. And I shouldn’t do it.”
That sort of ambivalence increases the reward value of the food. It increases the anxiety, it increases the arousal, it keeps it in working memory. We’re wired to focus on the most salient stimuli in our environment. For some people it could be alcohol or illegal drugs or gambling. For many of us it’s food.
Are you saying if you give in to the craving and eat whatever the desirable food is, it’s more likely that you’re going to do it again?
Of all the stimuli in the environment, why does that chocolate-chip cookie have such power? You make food hyper-palatable with fat, sugar and salt. It’s very stimulating and it becomes the most salient stimuli for many people.
What makes a food hyper-palatable? Even if you like apples, you’re probably likely to eat one and not gorge yourself on four more. Where as if you like nacho chips, you might eat way more than you had intended to when you started. What is the difference between these foods?
It starts with how many chews there are in a bite. If you take a stimulus and you get a sensory hit and it disappears, what do you do immediately next?
You take another bite.
We’re eating, in essence, adult baby food. Twenty years ago the average chews per bite was about 20, now it’s two or three. The food goes down in a whoosh and it’s very stimulating. It’s layered and loaded with fat, sugar and salt. It’s as if you have a roller coaster going on in your mouth. You get stimulated, it disappears instantly and you reach for more.
Of fat, sugar and salt, which is the most potent in this way?
Sugar is the main driver, but when you add fat to, it’s synergistic. So it’s more potent. We’re eating in a disorganised and chaotic fashion. And we’re being bombarded with the cues. We make food into entertainment. We make it into a food carnival. Go into a modern American or urban Indian restaurant: the colours, the TVs, the monitors, the music. The sugar and the fat and flavour in foods make up the multiple levels of stimuli.
Doesn’t fat make food easier to swallow without much chewing?
Fat enhances the sensory aspect of eating in multiple ways. When one thinks that one is eating for nutrition or to sustain oneself, one is actually eating for stimulation. Fat, is one such stimulant.
Do people who experience ‘conditioned hyper-eating’ experience more pleasure in food than other people?
It is not that there’s greater pleasure in food for people who crave food. It is just that they have greater sensitivity to the cues, greater thoughts of wanting, and that stimulates and activates their brain. Their anticipation is greater and it is much harder for them to resist food. They don’t taste food any differently than anyone else but they have a much greater struggle with the anticipation of food.
If you look at 2-year-olds, they compensate for their eating. If given more calories at lunch, they’ll eat fewer calories for the remainder of the day. By the time these kids are 4 and 5, they lose the ability to compensate. Given the exposure to fat, sugar and salt when they’re 3, 4 and 5, the reward pathways of the brain take over and hijack the normal body’s homeostatic mechanism to regulate itself. The brains of millions of children are being conditioned and this conditioning lasts a lifetime.
What should the government do to regulate the food industry to create a better food environment?
The government has two major roles: greater education and certainly greater disclosure. When the food that is being sold is hijacking the brains not just of adults but of children, that has implications for school lunches and food sold in school canteens. A parallel can be drawn with tobacco products. When the perception of the product changed from being glamorous to something that was deadly, disgusting and addictive product, its consumption also dropped.
Individual consumer action is also important. People should know that as the food manufacturers make the package bigger, people are going to consume more. Knowing that, at least they can put brakes on. Greater disclosure is the other thing that is badly needed. Just taking fat, sugar and salt and putting it in a lot of different forms, a lot of different colours, and selling it constantly, doesn’t contribute to nutrition. When consumers read on the labels that they are essentially having just these things, there will be higher awareness of the risks involved in eating nutrition-less foods.
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