Obesity has reached epidemic proportions globally, with more than one billion adults overweight, at least 300 million of which are obese; nationally, more than two-thirds of adults are overweight or obese, contributing to the burden of chronic disease and disability (WHO). In school you may have learned that body weight is assessed quantitatively by body mass index, kilograms per meter-squared (kg/m2), because tax payers finance millions of dollars in health education each year. Also, the diet and fitness industry has grown rapidly, promoting health awareness. Now it’s well known that being overweight puts an individual at risk to a seemingly infinite list of health complications, and worse it’s the second leading cause of preventable death. A historic reform bill was passed in Congress today that will further increase tax spending for healthcare, the reform extends coverage to the 32 million people that are uninsured. Drawing conclusions, there are billions of dollars being spent in health education to prevent overeating, but nearly 70% of people are overweight, nationally costly and personally damaging. Remarkably, there are rational psychological, environmental and physiological factors that explain why Americans overeat and accept the consequences.
Most simple being that the average consumer has more money to spend on luxuries than ever before. In 1992, the GDP per capita in the United States was $24,686, a $22,736 difference from today’s GDP per capita of $47,422 (Johnston and Williamson). There has been a small rise in inflation, but consumers can afford to buy plentiful amounts of food. Additionally, more people are dining at restaurants than in past decades. Restaurant food is typically higher in fat and calories than a traditional home-cooked meal. Worse, food manufacturers are always competing to offer bigger proportions at lower costs, and research suggests that people will eat more if they are given a larger serving. Consider how a regular soft drink from Burger King in the 70’s is now the kid’s size. Food is abundant, and overeating is affordable.
Another precursor to overeating can be linked to consuming foods and drinks high in fructose. Fructose is a natural form of sugar found in fruit, corn syrup, and honey. Alarming, because food manufacturers use an enormous amount of concentrated corn syrup to sweeten their products. A study found that after consuming fructose drinks, lower levels of insulin and leptin were present in the body. Insulin and leptin are hormones that regulate appetite. Also, those subjects had higher levels of ghrelin, a hormone that stimulates eating (Journal of Clinical Endocrinology and Metabolism). Corn syrup is used in a vast spectrum of products, like ketchup, fruit juice, and soda. It’s cheap to manufacture and appealing, but detrimental to the body’s natural hormones that control eating.
Additionally, overweight people have a habituation change that influences overeating. Habituation is the process in which a person’s saliva production normally declines after they have eaten enough and grown used to the taste of a food. The difference in habituation between an average weight adult and obese adult was observed in a study using lemon juice. Doctors measured baseline levels of saliva by dropping measured amounts of water on the volunteers’ tongues, and then made ten lemon juice tastings at regular intervals. Results showed that the obese group had a much smaller decrease in salivation than average (qtd. in Rabin). This research shows that people can overeat from another physiological change, a change in saliva production.
Moreover, overeating is emotionally driven, and recent study provides insight to how obese people use food to soothe their emotions. Scientists observed how the human brain responded to messages sent by the stomach, which was stimulated by an implanted device. Seven obese individuals were used for the research, and had these devices implanted for two years. The stimulator was similar to a pacemaker, providing electrical pulses to the vagus nerve, causing the stomach to expand and sending signals to the brain. Participants were injected with a radioactively labeled form of glucose, and then PET scanned to track brain metabolism. The scans were bi-monthly and the stimulator was disabled every two weeks. Results showed that hippocampus metabolism was increased during stimulation. The hippocampus is involved in emotional behavior, as well as learning,
memory, and sensory processes. Afterwards the participants answered a questionnaire and described that emotional eating was much lower when the device was active (ScienceDaily). This is a psychological explanation of the body’s emotional mechanisms that trigger overeating.
In conclusion, several physiological, environmental, and psychological factors may influence Americans to overeat in spite of the consequences. An overweight or obese person is known to be more susceptible to serious illness or harm. That said, and the financial exhaustion between health education and healthcare, overeating does seem unreasonable. However, those internal issues of overeating and personal choice do hinder any solution, and obesity rates will stay on the rise. Besides, an American hamburger tastes delicious.
Global Strategy on Diet, Physical Activity and Health. WHO. Web. 18 March 2010.
Johnston and Williamson. “What Was the U.S. GDP Then?” Table. Measuring Worth. Web. 18 March 2010.
Journal of Clinical Endocrinology and Metabolism. June 4, 2004;89(6):2963-72. Print. 18 March 2010.
Rabin, Roni. “Study Offers Clues to Why People Overeat.” New York Times. New York Times, 10 June 2009. Web. 17 March 2010.
“Study Offers New Clues to Brain-Stomach Interactions.” ScienceDaily. ScienceDaily, 3 Oct. 2006. Web. 17 March 2010