“National survey data show that the prevalence of overweight and obese adults in the U.S. has increased steadily over the past three decades,” said Youfa Wang, MD, PhD, lead author of the study and associate professor with the Bloomberg School’s Center for Human Nutrition. “If these trends continue, more than 86 percent of adults will be overweight or obese by 2030 with approximately 96 percent of non-Hispanic black women and 91 percent of Mexican-American men affected. This would result in 1 of every 6 health care dollars spent in total direct health care costs paying for overweight and obesity-related costs.”

The researchers conducted projection analyses based on data collected over the past three decades from nationally representative surveys. Their projections illustrate the potential burden of the U.S. obesity epidemic if current trends continue.

“Our analysis also shows that over time heavy Americans become heavier,” says May A. Beydoun, a former postdoctoral research fellow at the Johns Hopkins Bloomberg School of Public Health.

“The health care costs attributable to obesity and overweight are expected to more than double every decade. This would account for 15 to 17 percent of total health care costs spent,” Wang says. “Due to the assumptions we made and the limitations of the available data, these figures are likely an underestimation of the true financial impact.”

Current standards define adults with a body mass index (BMI) between 25 and 29.9 as overweight and adults with a BMI of 30 or higher as obese. Both the overweight and obese are at an increased risk for developing a number of health conditions, including Type 2 diabetes mellitus, high blood pressure, cardiovascular disease and may have a shorter life expectancy than their parents if the obesity epidemic is left unaddressed.

The authors warned that obesity has become a public health crisis in the U.S. Timely, dramatic and effective development and implementation of corrective programs and policies are needed to avoid the otherwise inevitable health and societal consequences implied by their projections. If current trends continue, the researchers say that the U.S. Department of Health and Human Services will not meet its Healthy People 2010 initiative to increase the proportion of adults who are at a healthy weight and to reduce the proportion of adults who are obese.

Lan Liang, PhD; Benjamin Caballero, MD, PhD and Shiriki Kumanyika, PhD, MPH, co-authored the study “Will All Americans Become Overweight or Obese? Estimating the Progression and Cost of the U.S. Obesity Epidemic.”

The U.S. Department of Agriculture and the National Institutes of Health provided partial funding for the research.

About Obesity

Obesity is a condition in which the natural energy reserve, stored in the fatty tissue of humans and other mammals, exceeds healthy limits. It is commonly defined as a body mass index (BMI) (weight divided by height squared) of 30 kg/m² or higher.

Mortality is increased in obesity, with a BMI of over 32 being associated with a doubled risk of death.  Central obesity (male-type or waist-predominant obesity, characterized by a high waist-hip ratio), is an important risk factor for the metabolic syndrome, the clustering of a number of diseases and risk factors that heavily predispose for cardiovascular disease. These are diabetes mellitus, Type 2 diabetes mellitus, high blood pressure, high blood cholesterol, and triglyceride levels (combined hyperlipidemia).

Apart from the metabolic syndrome, obesity is also correlated with a variety of other complications. For some of these complaints, it has not been clearly established to what extent they are caused directly by obesity itself, or have some other cause (such as limited exercise) that causes obesity as well. The affected health conditons include but are not limited to:

• Cardiovascular: congestive heart failure, stroke, enlarged heart and its associated arrhythmias and dizziness, varicose veins, and pulmonary embolism
• Endocrine: type 2 diabetes mellitus, insulin resistance, polycystic ovarian syndrome (PCOS), menstrual disorders, and infertility
• Gastrointestinal: gastroesophageal reflux disease (GERD), fatty liver disease, cholelithiasishernia, and colorectal cancer
• Renal and genitourinary: erectile dysfunction, urinary incontinence, chronic renal failure, hypogonadism (male), breast cancer (female), uterine cancer (female), stillbirth
• Integument (skin and appendages): stretch marks, acanthosis nigricans, lymphedema, cellulitis, carbuncles, intertrigo
• Musculoskeletal: hyperuricemia (which predisposes to gout), immobility,joint pain, osteoarthritis, low back pain
• Neurologic: stroke, meralgia paresthetica, headache, carpal tunnel syndrome, dementia, idiopathic intracranial hypertension
• Respiratory: obstructive sleep apnea, obesity hypoventilation syndrome, asthma
• Psychological: Depression, low self esteem, body dysmorphic disorder, social stigmatization
• Erectile Dysfunction