Rerouting Boston’s Central Artery required more resources than anyone imagined.
The “Big Dig” was the largest civil engineering project in U.S. history. Promised to cost $2.8 billion in 1985, it came in at $22 billion in 2007. These numbers are miniscule however when compared to the costs of tackling a human engineering problem—weight gain in America. Neuroscience has a remedy but it will require significant resources.
The Big Dig is a case study in underestimating the scope of a problem. Built in the 1950s, Boston’s Central Artery was an elevated six-lane downtown freeway. It was a rusting traffic jam by the 70s. Rerouting it required keeping the artery in operation while tunneling a new highway beneath it. The downtown area was largely landfill laced with subway lines and utilities kept in operation while moving them. With each shovelful of dirt, the scope of the Big Dig expanded, causing costs to soar.
Beating bulging waistlines will require a Bigger Dig. Two-thirds of Americans are overweight, one-third obese. Childhood obesity has tripled over the last 30 years. These statistics, while aching familiar, are not on the forefront of people’s minds when aching with hunger. The ache is unconscious—and this points to the scope of the problem.
Most of the time—roughly 95 percent—people are unconscious of whether they are actually hungry, how much they actually eat, how often they eat, and how fast they eat. It’s similar to driving a car, a process requiring thousands of decisions every second. To do this, drivers unconsciously apply pressure to pedals and steering wheels. Success in driving lies with the brain routing million bits of information along mental highways, making the driving experience largely but not exclusively unconscious.
The brain can in fact process about 14 million bits of information per second.1 It processes ‘bits’ by compressing them into bundles and routing them on to highways. On average, 100-200 bundles travel along these routes at one time but we can only be conscious of between five and nine of them.2 We are unconscious of the other 95 percent. “It is rule of thumb among cognitive scientists,” writes Cal Berkeley professor George Lakoff, “that unconscious thought is 95 percent of all thought.”3
This means individuals are 95 percent unaware of why they become hungry, as neuroscientists from Yale University have discovered. They had 13 overweight and 13 normal-weight subjects smell and taste chocolate or strawberry milkshakes and observed their brains with fMRI scans. Traffic in the amygdala—the emotional center of the brain—lit up in overweight people whether they were hungry or not. It only lit up in healthy-weight people when they were hungry. Neural pathways in overweight people lead them to unconsciously feel fatty foods will give them a sense of emotional well-being. This presents a problem since God designed human beings to seek well-being.
In another study, researchers from Columbia University in New York showed how images of cakes, pies, french fries and other high-calorie foods activate a widespread network of brain areas involved in reward, attention, emotion, memory and motor planning in overweight people. These networks trigger strong responses in the midbrain where dopamine, the “desire chemical,” is released.4 Neural pathways in overweight people lead them to unconsciously desire high-calorie foods. This presents a problem since God designed human beings to operate by desire.
None of this is necessarily new to students of the scriptures. In Jeremiah’s day, the Jews stumbled because they walked “in pathways, on roads not built up” (Jer.18:15). What is new are findings from neuroscience on how neural highways are pretty much in place by the age of 20, according to David Burnham of the Burnham Rosen Group. For adults to lose weight and keep it off, they have to keep the old central artery in operation—they have to eat—while tunneling a new pathway beneath it. The dig starts by becoming conscious of actually being hungry as well as learning how much, how often, and how fast an individual eats. There are many ways to do this, but it demands significant resources. This is why, Burnham writes, after age 20; only 20 percent of adults ever see a significant change in behavior, such as losing weight. A new highway has to replace the old one. When healthy eating becomes unconscious, it is a habit for the long haul.
Of course, the better solution is digging healthy highways before the age of 20. This is why First Lady Michelle Obama’s “Let’s Move!” campaign against childhood obesity is a wise investment of resources. Preventive medicine is always better than corrective. This is also where Sarah Palin and Glenn Beck reveal a naivety exceeded only by their certainty. When they rip the First Lady’s campaign, they’re saying behavior is mostly a series of conscious choices. Palin and Beck are utterly unfamiliar with 95 percent of what drives human nature.
There are instances of Bigger Digs in individuals over the age of 20. In his studies for the National Institutes of Health’s diabetes research center in Phoenix, Dr. Angelo Del Parigi, found adults who had successfully lost weight had increased activity in the dorsal lateral prefrontal cortex, a part of the brain involved in impulse-control in response to food. He also however found food still elicited strong responses in the brains of those who had lost weight, especially in areas involving addiction, reward, learning and memory. This suggests old highways are never torn down but new ones go around them. The Bigger Dig can be done, but it requires more resources than most imagine.
1 John Gray, Straw Dogs: Thoughts on Humans and Other Animals (London: Grant Books, 2002), p. 66.
2 Madeleine L. Van Hecke, PhD, Blind Spots: Why Smart People Do Dumb Things (Amherst, NY: Prometheus Books, 2007), p. 39.
3 George Lakoff and Mark Johnson, Philosophy in the Flesh (New York, NY: Basic Books, 1999), p. 13.
4 Melinda Beck, “Eating to Live or Living to Eat?” Wall Street Journal, July 13, 2010, D1.