فصل 11

11

OUTSMARTING THE HUNGRY BRAIN

Throughout this book, we’ve seen the powerful influence of the nonconscious brain on our eating habits. Although these ancient circuits kept our ancestors alive and fertile in an environment of scarcity, they get us into trouble today by following the rules of a survival game that no longer exists. The same responses that once helped us thrive now drive us to overeat, gain fat, and develop diseases that kill us and sap our vigor. As Anthony Sclafani’s and Eric Ravussin’s cafeteria diet studies illustrate, the pull of a fattening food environment can cause us to overeat tremendously without any intention to do so, and without even awareness that it’s happening. In today’s cafeteria diet world, the deck is stacked against us.

But we also know that if we change our environment, we can change the cues we send to the nonconscious brain, aligning its motivations with our goals of leanness and health. If the cues your brain receives favor overeating, you’ll probably overeat whether you intend to or not. If they don’t favor overeating, you probably won’t. If the nonconscious, impulsive brain is so influential, and if it acts according to the cues it receives, then the obvious path to effective weight management is to give it the right cues. How do we do that? We can divide approaches into two categories: things we can do as a nation and things we can do individually.

TACKLING THE OBESITY EPIDEMIC

There are a variety of public health measures that could guide our eating behavior in a healthier, more moderate direction as a nation. Yet if we want to have a meaningful impact on the nation’s waistline, we’re going to have to get a lot more serious about it than we currently are. Kevin Hall’s research shows that Americans would have to reduce our average calorie intake by at least 218 Calories per day to return to our 1978 body weights, a reduction of nearly 10 percent. Alternatively, we’d have to burn 218 extra Calories exercising—which represents almost half an hour of jogging every day—and hope we don’t work up an appetite. In reality, the situation is even more challenging, because not everyone overeats. If we average 218 excess Calories, what that really means is that some people don’t overeat at all, while others overeat by 400 Calories or more per day. And the latter population is the one that public health measures would have to target. Humble arithmetic suggests that halfhearted efforts aren’t going to cut it.

That said, what tools do we have at our disposal? The first strategy is simply to give people information on how to eat a healthy diet. Unfortunately, as we’ve seen, that approach by itself seems to have little impact on calorie intake. People do need good information to make good choices, but information alone isn’t enough to substantially change behavior because it doesn’t target the primary brain circuits that are in charge of calorie intake.

Nutrition labeling is an example of this approach. While labeling has had some victories like pressuring manufacturers into reducing the trans fat content of processed food, telling people how many calories a food contains seems to have little impact on their overall calorie intake in real life. I would argue that it targets the wrong brain circuits.

Whether they view their approaches in these terms or not, public health professionals already have a number of weapons in their arsenal that target the impulsive brain. For example, our consumption patterns can be shifted by a strategy called countermarketing. This basically means running negative ads that associate certain products with bad feelings, unpleasant images, or disturbing information (an example of negative reinforcement). It’s the opposite of what ads normally do. Antitobacco countermarketing, with its gory images of blackened lungs and tracheostomies, included ads on television and billboards, and stern warning labels on cigarette cartons. Coupled with crippling tobacco taxes and a growing number of public and private smoking bans, countermarketing contributed to the fact that Americans today smoke 70 percent fewer cigarettes per person than we did in 1963.

While the decline in cigarette smoking is a huge public health victory that has prevented a great deal of disease and suffering, it was only possible due to a unique combination of factors that doesn’t exist for fattening food. First of all, cigarettes aren’t essential for life, whereas food is. This means we would have to countermarket against fattening foods but not others. It’s much more challenging to split nutritional hairs than it is to oppose an addictive drug wholesale. Second, tobacco countermarketing was (and is) funded by tens of billions of dollars in legal settlements that resulted from antitobacco lawsuits in the 1990s. There is currently no such funding for food countermarketing efforts.

Another way to guide our eating behavior in the right direction is to make fattening foods a less attractive “deal” to the brain regions that guide our economic choices. Monetary cost is part of this equation, and as such it has received a lot of attention from public health professionals. Simply stated, we tend to buy less of specific foods as they become more expensive and more as they become cheaper. By making fattening food more expensive and slimming food cheaper, we can shift the cost-benefit balance to favor a more moderate calorie intake.

Several countries have already implemented taxes on foods that are considered unhealthy, including Denmark’s tax on saturated-fat-rich foods and Mexico’s tax on sugar-sweetened beverages. Yet fierce opposition from the food industry and the general public led Denmark to scrap its tax little more than a year after it was implemented. Mexico’s soda tax has effectively, if modestly, reduced sugar-sweetened beverage intake in one of the fattest countries in the world. At the time of this writing, it’s already vulnerable to new legislation only two years after being implemented. Not surprisingly, the soda industry has been working hard to undermine it, and they have a lot of leverage since Mexico’s government has strong ties to big soda (for example, Vicente Fox, the president of Mexico from 2000 to 2006, is the former president of Coca-Cola Mexico).

An alternative way to financially nudge our diet in the right direction is simply to change the way government subsidies are allocated to commodity crops, such as corn, soybeans, and wheat. These three food crops receive more subsidies than any others in the United States—totaling over $10 billion per year. They also happen to be the basis for many of our most fattening food ingredients, such as high-fructose corn syrup, white flour, soybean oil (the primary added fat in the United States), corn oil, and corn starch. In turn, the food industry uses these artificially cheap ingredients to compose extremely tempting and unbelievably low-cost foods—a deal that’s hard for the brain to pass up. Essentially, taxpayers are subsidizing the very foods that make them fat and sick. Shifting subsidies away from foods that make us fat, and toward foods that don’t, is a common-sense idea that could have a substantial impact on the American food system, and ultimately our waistlines. I’ll leave it to the economists and farmers to understand the complex ramifications of changing our subsidy system, but it seems to me that we should be able to support farmers and food security without undermining our nation’s health.

Convenience is an additional public health lever that can modify our eating behavior by impacting the brain circuits that govern economic choice. For example, in Detroit there’s a zoning law that requires a minimum of five hundred feet between fast-food restaurants and schools (that’s a bit less than two football fields). However, very few communities have passed such ordinances, and in most cases, the goal was to protect the character of a historic area rather than to promote health.

Food assistance programs like the Supplemental Nutrition Assistance Program (SNAP; formerly named the Food Stamp Program), which supports low-income American individuals and families, represent an additional intervention point. These programs target economically disadvantaged groups that are more likely to have obesity and chronic disease. Currently, 45 million Americans use SNAP, so it’s a powerful leverage point for improving diet and reducing obesity risk. The government does limit what SNAP recipients can do with the money they receive: It can be used to buy groceries and seeds to grow food, but it cannot be used in restaurants. Although it’s not difficult to compose an atrocious diet from grocery store foods, skipping restaurants is a step in the right direction. In the case of food assistance programs, we seem to be a little bit more comfortable with the government influencing food choices because the recipients aren’t spending their own money. This could present a valuable opportunity to nudge our diet in the right direction, perhaps by providing financial incentives to buy healthy food rather than unhealthy food.

The food industry has long known that one of the most effective ways to get a person to buy a particular food is to show her an appealing image of it. If she has eaten the food before, or something similar, this visual cue triggers dopamine release and the motivation to eat the food (craving). This fundamental property of the human brain is one of the main reasons why the food industry spends tens of billions of dollars on advertising each year. The public health intervention here is obvious: Regulate food advertising. Yet in the United States, the government places few restrictions on food advertising. The research of the University of Connecticut’s Rudd Center for Food Policy and Obesity shows that both children and adults in the United States are inundated every day by a deluge of food advertisements, most of which promote unhealthy, calorie-dense items. Americans are well aware of the insidious effect of food advertising on our food preferences and eating habits, yet we’re reluctant to let the government step in.

In theory, the food industry can regulate itself, and this is a lot more palatable to the industry and the public than government regulation. All else being equal, food industry executives would rather not have their products fuel the obesity epidemic, and under pressure from government and private organizations, many companies have already taken action. One such effort is the Children’s Food and Beverage Advertising Initiative (CFBAI), a voluntary program introduced in 2006 that regulates food advertising to US children under age twelve. Most of the largest food industry players are on board, including Kraft, Coca-Cola, and General Mills. CFBAI participants agree to restrict advertising of unhealthy foods on children’s TV shows, requiring that advertised foods meet specific criteria for calorie, saturated fat, trans fat, sugar, and salt content. Foods don’t have to be particularly healthy or slimming to meet the CFBAI’s criteria, but the guidelines do restrict the worst offenders, and the food industry seems to comply with them reasonably well.

Not everyone has a rosy view of the CFBAI, however. The Rudd Center points out that children are often exposed to media that’s targeted at adolescents twelve to eighteen years old, or adults, and these advertising arenas are unrestricted. So while these companies do restrict food advertising aimed directly at children, when they advertise unhealthy food to other age groups, there is a lot of collateral damage to children. The Rudd Center also reports that the nutrition standards used by the CFBAI are not as stringent as those recommended by independent organizations like the federal Interagency Working Group. Despite these problems, it’s hard not to view the CFBAI as a step in the right direction.

Sadly, CFBAI is arguably the most impressive example of US food industry self-regulation in the interest of public health. The fundamental problem is that the food industry is governed by the incentives of a fiercely competitive free market economy, and these incentives sometimes conflict with human health. For example, in the 1970s, Nestlé initiated a campaign to promote its infant formula over breast milk in developing countries, despite the fact that contaminated local water supplies often made formula feeding dangerous. It was a profitable venture, but at the cost of substantial infant mortality. The situation was eventually resolved by boycotts and international regulation. Although not all instances of conflict between profits and human health are so egregious, competition nevertheless creates a “race to the bottom” in which companies jockey to produce the most compelling foods possible and advertise them in the most visible, attractive ways. To do this, they titillate the brain circuits that determine our innate nutrient and economic preferences—which are the same circuits that push us to overeat. The end result is a food system that’s expertly, if unintentionally, crafted to drive overeating.

Reducing the fattening qualities of a food tends to make it less appealing to the average consumer, who then votes with his wallet by buying something else. For example, McDonald’s has made several attempts to improve the health profile of its offerings, such as phasing out the Supersize option and adding fresh fruit and salads to its menu. Yet its US sales sagged in the wake of these changes. Other companies were quick to take up the slack, as illustrated by this quote from Hardee’s CEO Andrew Puzder about their 1,400-Calorie “Monster Thickburger”: This is a burger for young hungry guys who want a really big, delicious, juicy, decadent burger. I hope our competitors keep promoting those healthy products, and we will keep promoting our big, juicy delicious burgers.

Hardee’s sales were brisk following their introduction of the colossal hamburger.

Because many of the qualities that coax us to purchase a food are also those that make us overeat, any individual company that voluntarily makes its food less fattening is effectively entering the boxing ring with one hand tied behind its back. Executives and shareholders both realize that having one hand tied behind your back usually leads to getting punched in the face. This creates a fundamental conflict between profits and public health—and in the grand scheme of things, profits usually prevail. In my view, the only realistic way out of this downward spiral is nationwide regulation that encourages a more slimming food environment while maintaining a level economic playing field for the food industry. This could happen through industry self-regulation and/or government regulation, but I seriously doubt industry has what it takes to self-regulate us out of our overeating problem.

Although public health legislation would undoubtedly be an effective antiobesity tool if we got serious about it, few Americans, and even fewer food industry executives, have much appetite for it. We tend to have a dim view of government meddling in general, and in particular when it comes to our food. I can sympathize with that perspective—we want to forge our own path through life. Yet we’ve already walked many miles down the wrong path, and it has caused millions of American children to grow up with obesity-related physical and metabolic disabilities before they have a choice. These children will have a much higher chronic disease risk, a lower life expectancy, and a lower quality of life as a result of improper nutrition. This tragic situation is largely preventable, yet our halfhearted attempts to do so have failed. It’s time to ask ourselves a serious question: What do we care more about, the health of our nation’s children or our freedom to be bombarded by cheap, fattening food?