The prevalence of obesity continues to increase worldwide. Reports indicate that in 2005, 1.6 billion individuals over the age of 15 were overweight, and at least 400 million were obese. Projected figures indicate that this will continue to increase, and that by 2015, 2.3 billion adults will be overweight, and more than 700 million will be obese. Though data from the Centers for Disease Control and Prevention (CDC) indicate that obesity rates among Americans have peaked, World Health Organization (WHO) statistics point to increasing obesity rates in both the developed and developing world.
Abnormal or excessive accumulation of body fat often indicates that an individual is “overweight” or “obese.” The body mass index (BMI) – the weight of an individual in kilograms divided by the square of their height in meters – provides a crude measure to determine into which category an individual falls. According to the WHO, a person with a BMI between 25 and 30 is generally considered overweight, and over 30 is generally defined as obese. Overweight and/or obese individuals are more susceptible to many serious health complications. Excess body weight has been shown to increase the risk of ischemic stroke by 22 percent in overweight individuals, and 64 percent in obese individuals. The Mayo Clinic reports that obesity can cause a number of additional health complications, including high blood pressure, heart disease, osteoarthritis, and type 2 diabetes. Reports also indicate that “in the U.S…. [an estimated] seven types of cancer…are weight related [and] just under 20 percent could be prevented through people being a healthy weight.”
Obesity is commonly thought of as a condition of the developed world. However, a 2007 survey found that the South Pacific island of Nauru was the nation with the highest percentage of overweight people – 94.5 percent of its population. Other small nations including the Federated States of Micronesia, Cook Islands, Niue, and Tonga were noted among the nations with over 90 percent of the population overweight or obese. The WHO notes that the “increased consumption of more energy-dense nutrient-poor foods…[and] reduced physical activity” have led to increased obesity rates worldwide. According to experts, people around the globe are being introduced to more “Western” lifestyles which often include an influx in the supply of unhealthy choices, reduction in exercise, and higher-stress occupations.
While this shift affects individuals worldwide, they are somewhat magnified in the United States where in the past 30 years, the number of obese adults has doubled, reaching nearly 34 percent, and the number of obese children has tripled to 17 percent. A study from the University of Michigan Health System shows that more Americans are becoming overweight or obese at a younger age and carrying the extra weight for longer than previous generations. According to research from Oxford University, the life expectancy of moderately obese individuals is reduced by about three years, and severely obese individuals’ life expectancy is reduced by 10 years. While obesity can be attributed to poor dietary selections or a lack of physical activity, research from the University of Texas Medical Branch at Galveston shows that a tendency towards obesity can be detected in infants as young as 6 months of age, and many of these infants are likely to continue to carry extra weight as they mature. To identify a means of overcoming obesity, researchers have continued to try to locate a genetic cause and help to improve treatment options. Findings from a indicate that the Chinese studyfat mass and obesity-associated gene (FTO) may be strongly linked to the predisposition for some individuals to gain weight more rapidly than others.
While there may be both genetic and behavioral causes for obesity, it can be prevented. Recent studies indicate that in teenagers who carry the FTO gene, physical activity can help to mitigate its effects. By gaining an understanding of the causes of obesity and preventative measures that can be taken, it may be possible to reduce its likelihood and detrimental effects.