"Overweight" is a term that refers to an excess amount of body weight that typically comes from muscles, bone, fat and water; however, "obesity" means an excess amount of body fat. Body mass index, BMI, is a weight-for-height measure commonly used to classify overweight and obesity in adults. For most people, BMI correlates with body fat percentage. People who are obese are at an increased risk for several adverse health conditions, including: high blood pressure, stroke, sleep apnea and breathing issues, joint problems, some types of cancer, and mental health disorders, among others.
Obesity Rates: Then And Now
Approximately 10 percent of U.S. adults were classified as obese during the 1950s. In 2011 to 2012, however, the CDC reported approximately 35 percent of U.S. adults were obese; the prevalence of obesity among American adults has more than tripled within the last six decades.
National surveys of childhood obesity weren't recorded before 1963; however, the rate of childhood obesity in the U.S. began to rise in the 1980s. In 1980, 7 percent of children ages 6 to 11 were obese; in 2012, the rate was nearly 18 percent. In adolescents –12 to 19 years of age– the increase in obesity rates was more striking, climbing from 5 to 21 percent during the same period.
What Caused the Rise in Obesity?
Many reasons account for the rise in obesity rates in the U.S. The average restaurant meal is four times larger than it was in the 1950s. Similarly, the size of American-manufactured dinner plates has increased nearly 23 percent, from 9.6 inches to 11.8 inches, since 1900. A study published in a 2012 issue of the Journal of Consumer Research describes the subconscious bias to consume more food when served on larger dinner plates. These larger portions at restaurants and at home, increased added sugars; improved technology resulting in more "screen time" spent in front of computers and television; stress and lack of sleep, and even the temperatures of our homes and workplaces are documented reasons that promote American's growing waistlines.
The complete picture underlying the obesity problem is complex and includes roles for genetics and dysfunctional reward systems meant to regulate food intake.
Racial and Ethnic Disparities in Obesity
Obesity rates have increased across the U.S. for both genders, all ages and ethnic groups; however, some groups are more severely affected than others. The prevalence of obesity among American adults was 35 percent in 2011 to 2012. However, among black Americans, the rate was 48 percent. The difference is even more striking among women, with 37 percent of all American compared to 57 percent of black American women classified as obese. Disproportions in obesity prevalence also exist for Hispanics; again, more notably for women.
"It is not about one group doing something wrong," says Dr. Donald Lloyd-Jones, chair of the Department of Preventative Medicine at the Northwestern University Feinberg School of Medicine in an interview with NPR. "It is about the environment that we have built that sets up people to fail."
Effective Weight Loss for the Long Haul
Reversing the obesity epidemic in the United States involves prevention of weight gain and interventions at the individual, social and community levels. One helpful resource is the National Weight Control Registry, NWCR. The NWCR is a database tracking over 10,000 individuals who have succeeded at significant, sustained weight loss, and the average registry member lost an average of 66 pounds and kept it off for 5 1/2 years. Some members have lost 30 pounds, while others have lost 300. Although the range is substantial, lifestyle changes that promote and sustain any weight loss are worth noting. For example, 90 percent of NWCR members reported that they exercise – on average – about 1 hour daily. Nearly 80 percent eat breakfast daily, and 75 percent weigh themselves weekly.
On the community level, elementary schools can encourage students to drink water in place of sugar-sweetened beverages and make healthier choices available. Many schools can promote student health through a school-wide wellness policy. Workplace wellness initiatives should be ongoing to encourage regular physical activity and healthy lifestyles for employees. For minority groups, effective interventions have included using school property as recreation facilities during non-school hours and increasing nutrition assistance and education programming.
- U.S. Department of Health and Human Statistics: Overweight and Obesity Statistics
- CDC: The Health Effects of Overweight and Obesity
- Weiss, J. Why We Eat…and Why We Keep Eating. Insulite Laboratories.
- CDC: Childhood Obesity Facts
- AHA: Understanding the Obesity Epidemic
- Ittersum, K.V. and B. Wansink. Plate Size and Color Suggestibility: The Delboeuf Illusion’s Bias on Serving and Eating Behavior; Journal of Consumer Research.
- The State of Obesity: The Numbers
- NPR: Obesity Maps Put Racial Differences On Stark Display
- The National Weight Control Registry: NWCR Facts
- The State of Obesity: Obesity Prevention in Black Communities