A Big Fat Crisis (2 page)

Should I blame myself for my failure to make healthy choices?
Should I hold myself responsible for eating too much chocolate? For my untoned, sagging biceps and belly? Should you? When we’re on our own, who else is there to blame?

Because I have many family members and friends who are overweight or obese,
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my interest in addressing the epidemic is both personal and professional. Unlike most medical doctors who see patients for a living, I specialize in public health. Rather than helping individuals with their medical problems, I study entire populations, trying to pinpoint why people engage in behaviors that lead to ill health. With board certification in public health and preventive medicine, as well as a master’s degree in epidemiology—the study of the incidence, distribution, and control of disease across a population—I have spent more than twenty-five years studying why people engage in risky, unhealthy behaviors like smoking, drinking too much, having sex without a condom, eating too much, and exercising too little. For the past twelve years, as a scientist at the RAND Corporation, my focus has been on the obesity epidemic and how we can reverse it.

There are plenty of guidelines intended to help people figure out what to eat. The Dietary Guidelines for Americans, a consensus on what people should and shouldn’t eat to stave off obesity and diet-related chronic diseases, haven’t changed much in the past fifteen years. Even if you’ve never read them, you can probably guess what they say: eat your fruits and vegetables and go easy on sweet, salty, and fatty foods. Not very complicated, yet only 3 percent of Americans faithfully adhere to the recommendations.
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Similarly, the recommendation for physical activity has remained constant for nearly twenty years. Adults should get at least 2.5 hours of moderate exercise every week (e.g., thirty minutes five times per week), and children should get sixty minutes every day.
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Yet fewer than
5 percent of adults and less than half of all children exercise enough to achieve these modest goals.
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As a result of not meeting either the diet or physical activity guidelines, two out of three adults and one out of three children in this country are overweight or obese.
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Although in theory we know what to do to optimize our health—eat reasonable portions of nutrient-rich food and exercise regularly—in practice we don’t do it.

This gulf between our knowledge and our actions has long plagued me. As a physician and public health researcher who has studied obesity for more than a decade, I am especially aware of what I
should be
eating and how much I
should be
exercising. And I’m especially aware of the consequences of being obese: higher rates of diabetes, heart disease, hypertension, osteoporosis, and even cancer. Still, like most Americans, I find that this understanding only goes so far. It doesn’t dissuade me from eating more sweets than I should, and it doesn’t propel me to go jogging after a long day of work. I want to be healthier and stronger, I want to live longer and continue to lead an active lifestyle for years to come, but I fail to take the necessary steps to make this happen. And so do most Americans.

From a rational perspective, the motivation to eat well is clear. Research suggests that

       
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Being obese doubles one’s risk of dying prematurely.
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•
  
Eating too many trans fats increases the risk of coronary artery disease by 23 percent.
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•
  
Eating too little fiber increases the risk of colon cancer by 18 percent.
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•
  
Drinking one sugar-sweetened beverage every day increases the risk of diabetes by 83 percent in women.
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•
  
Excess dietary salt is believed to be responsible for 62 percent of all strokes.
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The research demonstrating the harms from eating too much food, especially too much sugar, is becoming increasingly clear and graphic. The Pennington Biomedical Research Center in Baton Rouge, Louisiana, whose mission is to tackle nutrition-related problems, recently
showed how healthy people can develop risk factors for heart disease and diabetes merely by being fed too much.

To precisely measure what happens to the overfed body, Pennington scientist Alok Gupta recruited fourteen healthy volunteers, with no hypertension, no diabetes, no heart disease, and a normal waist size, and had them eat all their food at Pennington for two months. During this time they were poked, prodded, and observed to see what was going on internally when the calories in their diet were increased.

In the first week the volunteers spent an entire day in a metabolic chamber to have their daily energy requirements assessed. They had biopsies to measure the size of their fat cells and MRIs to measure the volume of all their fat, including the fat in their internal organs as well as the fat stored under the skin and around the waist. After quantifying the volunteers’ total body fat, total body muscle mass, and total body water, Gupta measured the fat in their livers and the fat around their lower legs and in the calf muscles. He measured the baseline functioning of all their organs—the liver, the pancreas, and all the hormones related to eating, like insulin and leptin. He also measured inflammation in the blood and tested how well the blood vessels function by seeing how quickly blood vessels in a single finger recovered after the circulation was cut off for five minutes. And for seven days, while the volunteers wore an accelerometer to record how active they were, their blood pressure was also measured every thirty minutes.

Then, every day for the following seven weeks, the volunteers were served 40 percent more calories than needed to maintain their current weight. As they stuffed themselves, the measurements continued to record what happened to their organs, blood pressure, hormones, fat cells, muscles, and blood vessels.

On average, the group gained more than sixteen pounds, their body fat increased by 2 percent, and their waists grew more than three inches. Extra fat was deposited in organs rather than in muscle, especially in the liver. The average fat cell size grew by 54 percent.

Indicators of systemwide inflammation increased by 29–50 percent. Fasting blood sugar (an indicator of diabetes), cholesterol, and insulin resistance all increased. Blood pressure and heart rate went
up and blood vessel functioning capacity was reduced by about 21 percent—altogether demonstrating a significant increase in factors associated with heart disease.

At the end of seven weeks, most of the volunteers still felt fine and had measures that remained within the normal range. But it was very clear that continuing the trajectory would have led to serious problems.

Although most people understand that being overweight or obese puts them at a greater risk for all kinds of diseases, especially life-threatening ones, on a day-to-day basis the consequences seem pretty remote. The body changes happen gradually, and without these detailed measures they often go undetected. Moreover, even if we put on two pounds per week, we generally don’t get any obviously recognizable symptoms letting us know that any internal damage is occurring. Most people put on one to two pounds per year, so it would take more than eight years to match what the Pennington volunteers gained in eight weeks.

Although there is no doubt that obesity increases the risk of a wide variety of medical problems, what is less well understood is why people eat too much even though they are aware of the negative consequences.

The conventional wisdom is that obesity is the expression of individual weakness, gluttony, and/or lack of personal responsibility. Some claim that the current epidemic, therefore, indicates that a substantial portion of the population has lost all sense of self-control while the rest are intentionally choosing to become fat.
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This is where I am extremely skeptical.

The increase in obesity cannot simply be an isolated matter of lack of self-control. Why? If the absolute loss of self-control was responsible for the obesity epidemic, it would mean that people in this country had more willpower thirty years ago, when the rate of obesity was half of what it is today. It would mean that people in countries with lower rates of obesity like Japan, Costa Rica, Sweden, and Finland are more controlled, more responsible, and perhaps even morally superior to Americans. Is that plausible?

The fact is, the majority of people who are overweight appear to have plenty of self-control in most other areas of their lives. They have
completed school and earned college or higher degrees; they maintain full- or part-time jobs, arrive at work on time, complete their assignments, raise successful children, vote, volunteer, and contribute to society in many ways. Few get into trouble with the law or are violent, impulsive, or irresponsible in ways that demonstrate low self-control.

Based on my own research, as well as the latest insights from behavioral economics, psychology, cognitive science, and the social sciences, the pages that follow describe the surprising forces behind the obesity epidemic and how we, as a nation, can overcome them.

My conclusions contradict conventional wisdom and widely held expert opinion, and go against our intuitive belief that people are fully in control of what they eat. They suggest that our basic assumptions about human nature and how our DNA is hardwired must be changed. Accepting that humans face limitations that interfere with self-control represents, in short, a paradigm shift in how we approach the problem of obesity—and the solution.

Specifically,
A Big Fat Crisis
argues that the obesity epidemic is the product of two forces:

       
(1)
  
Immutable aspects of human nature, namely the fundamental limits of self-control, the inflexible decision-making strategy of the brain’s noncognitive system, and the automatic and unconscious way that we are hardwired to eat; and

       
(2)
  
A completely transformed food environment, by which I mean all the food-related elements of our surroundings, including grocery stores, restaurants, prices, portion sizes, availability, marketing, and advertising.

The book focuses in equal measure on human nature, with its irrational and unconscious decision-making process when it comes to eating, and the modern food environment, which puts cheap, high-calorie, low-nutrient foods at our disposal in a way that is unprecedented in human history. Drawing on cutting-edge research from a variety of disciplines, I argue that the current discussion surrounding obesity, with its primary focus on individual responsibility and self-control,
demonstrates a fundamental misunderstanding of human nature. We are biologically designed to overeat when presented with the opportunity (that is, to eat more than we need in order to ensure our survival); most of us have a shockingly limited capacity to deliberately and consistently regulate our eating behaviors; our eating behaviors are not a matter of thoughtful, mindful decision-making, but instead happen automatically, without our full awareness.

Nevertheless, we assume that most people are rational and that we ourselves are even more rational than others. We see ourselves as powerful agents who decide what we will or will not do on a daily basis, particularly when it comes to our basic preferences, like how we spend our time and what we consume. We believe that we all have the capacity to control what and how much we eat. Although researchers in behavioral economics, cognitive science, and psychology have begun to poke holes in the rational-actor theory of human behavior, most of us still cling to this notion of omnipotence when it comes to food. If you’re being honest, I bet you blame yourself when you are unable to resist temptation—and probably hold overweight individuals accountable for their size.

If the limitations of human nature explain why we are prone to make unhealthy choices, the modern food environment practically assaults us wherever we go. The number of restaurants in America has more than doubled since 1977, and is still growing.
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The number of vending machines has also increased exponentially. When I was a child, vending machines were a rarity, and they usually sold either gumballs or cigarettes. Today, vending machines are in practically every office building, gas station, and public venue in the country. Advertising, too, has become increasingly sophisticated and insidious, so much so that we might not even recognize it as advertising: movie scenes feature actors eating name-brand foods, and the judges on
American Idol
sip Cokes as they dole out their scores.
A Big Fat Crisis
argues that the modern food environment is the largest determinant of our behavior—and what we need to focus on if we are going to end the obesity epidemic.