DECISION MAKING AND HEALTH RISK

Decision Making and Health Risk

Decision Making and Health Risk

Introduction

An estimated 60% of adults in the United States and Britain are currently overweight or obese—a marked increase from recent decades—and they are becoming so at an earlier age than ever before. Data from a number of reliable sources suggest that the pattern of population weight gain over the past generation has been due largely to an overconsumption of energy rather than a decrease in physical activity patterns. However, the fattening of our society goes well beyond esthetic issues; 300,000 people in the United States alone die each year of obesity-related illnesses, and this condition affects more people than smoking, heavy drinking, and poverty. More sobering is the prediction that, if current trends continue, 100% of Americans will be obese by the year 2230.

Overeating as an Addictive Behavior

The evidence of common brain mechanisms mediating the rewarding properties of natural rewards (like eating) and addictive drugs supports the argument that food—especially when it is highly palatable—can be used for purposes that exceed basic energy requirements, and it has the potential for abuse. For instance, many people report using food to "self-medicate" a disturbed affect. Of relevance is research showing that sweet foods, like certain addictive drugs, can produce significant analgesic effects. Excessive food intake can also induce physiological responses that mimic those seen in drug addiction—viz (Shtasel 2001). down-regulation, sensitization, and withdrawal. One study has demonstrated that repeated and high intake of sugar causes behavioral and neurochemical signs of withdrawal in rats when its availability is restricted. In addition, the fact that binge eating is often triggered by the ingestion of small amounts of a palatable food parallels the "priming" effect of drugs in addicts, whereby the initial ingestion of the drug tends to elicit a strong "craving" or compulsion for further use (Grant 2000).

Environmental Factors

Although the tendency to consume an excess number of calories each day can be influenced by several factors, dietary variety, especially of energy-dense foods, has consistently been associated with increased body weight. A recent animal study has also found that overconsumption is induced in rats who have greater availability of palatable food. Tordoff believes that the rats in his study ate more simply because they encountered desirable food more frequently—what he calls "obesity by choice." Given the substantial availability and variety of nutrient-poor, energy-dense foods in most Westernized countries, this finding has significance for understanding the increasing prevalence of human obesity.

Whether the pun in Tordoff's phrase (obesity by choice) was deliberate or not, it raises an interesting distinction between rodent and human eating behavior. Clearly, there is complex neural circuitry prompting physiological drives that regulate feeding behavior. However, in the human condition, the "choice" to eat (or not to eat) is under a degree of cognitive control not present in the rat. With ubiquitous warnings from the medical profession, it is fair to assume that, in our current culture, few adults are unaware of the health risks associated with obesity and poor ...