In 2005 to 2006, 33.3 percent of adult males and 35.3 percent of adult females in the United States were considered obese [source: CDC]. When you pool together everyone considered obese plus the overweight population, the tally rises to include nearly two out of three adult Americans [source: Philipson et al.].
Carrying extra weight, even as little as an extra 10 pounds (4.5 kilograms), isn't good for any of us. Being overweight or obese increases the risk for hypertension, coronary heart disease, high cholesterol, osteoarthritis, type 2 diabetes, stroke, gallbladder disease, sleep apnea and asthma, and has been linked to some cancers, including breast, endometrial and colon [source: CDC]. The U.S. Surgeon General reports obesity contributes to an estimated 300,000 deaths each year in the United States alone, compared with the roughly 400,000 deaths a year attributed to cigarette smoking [source: U.S. Department of Health and Human Services].
For years, doctors and health professionals have been schooling us on the benefits of a healthy diet and daily exercise, yet the number of obese people in the United States increases annually, blind to gender, age and race. Reasons for the obesity epidemic are complicated, but factors generally implicated include our behavior, genes, environment, culture and socioeconomic status.
The economic costs of obesity are, themselves, corpulent. In 1995, costs associated with obesity reached $99 billion [source: Wolf and Colditz]. And according to the Surgeon General's "Call to Action to Prevent and Decrease Overweight and Obesity" report, costs in 2000 rose to more than $117 billion [source: CDC]. This includes not only the direct costs of preventative care, treatment and medications for obesity, but also the associated indirect costs of lost income, low productivity due to job absenteeism and premature death.
The science of economics can be applied to health care, and doing so can give us insights into why obesity rates are increasing. Health economists study how we can get the biggest bang for our buck by looking at clinical effectiveness and the cost-effectiveness of the health care industry; they also evaluate how equitably health benefits are distributed among the population.
In 2007, economist Charles Courtemanche analyzed the average U.S. state fuel prices and U.S. government-reported health trends of the last 20 years and determined that as gas prices increase, so does the amount of exercise we get, while rates of dining out drop. Is there a correlation between gas prices and obesity? According to Courtemanche's thesis, yes.
Let's look more closely at Courtemanche's findings and see how gas prices, weight and eating habits are linked.