Primary Care>Obesity

Obesity Rates Continue to Rise Among Americans

-Prevalence increased by 12% for adults from 1999-2000 to 2017-2018, according to NHANES data

by Zeena Nackerdien PhD, CME Writer, MedPage Today 2020-12-29

Obesity Rates Continue to Rise Among Americans | MedPage Today

Study Authors: Cheryl D. Fryar, Margaret D. Carroll, Joseph Afful

Target Audience and Goal Statement: Endocrinologists, primary care physicians

The goal of this report was to examine trends in the prevalence of overweight, obesity, and severe obesity among children, adolescents, and adults in the U.S.

Questions Addressed:

  • What was the prevalence of overweight, obesity, and severe obesity among American adults ages 20 and older from 1960-1962 through 2017-2018?
  • What was the prevalence of overweight, obesity, and severe obesity among American children and adolescents ages 2-19 from 1963-1965 through 2017-2018?

Synopsis and Perspective:

Using measured height and weight, the CDC defines people with a BMI below 18.5 as being underweight, those with a BMI of 18.5 to 24.9 as normal or healthy weight, those with a BMI of 25.0 to 29.9 as overweight, and those with a BMI of 30.0 and above as obese. A BMI of 40 or higher is categorized as severe obesity.

Action Points

  • The prevalence of obesity in American children, adolescents, and adults was higher than it has ever been in nearly 60 years, according to data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES).
  • Realize that complex relationships between genetic, socioeconomic, and cultural influences can contribute to obesity, and eating patterns, urban development, and lifestyle habits can influence its prevalence.

For children and adolescents, BMI is age- and sex-specific, since their body composition varies as they age and varies between boys and girls. For children and adolescents of the same age and sex, a BMI at or above the 85th percentile and below the 95th percentile signals overweight, a BMI at or above the 95th percentile indicates obesity, and a BMI at or above 120% of the 95th percentile shows severe obesity.

Complex relationships between genetic, socioeconomic, and cultural influences can contribute to obesity, and eating patterns, urban development, and lifestyle habits can influence its prevalence.

According to data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES), the prevalence of obesity in American children, adolescents, and adults was higher than it has ever been in nearly 60 years.

Among American adults ages 20 and older, 42.4% had obesity, reported Cheryl Fryar, MSPH, of the National Center for Health Statistics (NCHS) in Hyattsville, Maryland, and colleagues in the latest Health E-Stats.

Another 30.7% of adults were categorized as overweight, and 9.2% had severe obesity.

When the results were stratified by age, adults 40 to 59 saw the highest rates of obesity, with 45% of this age group with a BMI of 30 or higher. Middle-age men had the highest prevalence of obesity, at a rate of 46%.

The rates of obesity also varied according to ethnicity, noted Fryar and team.

Non-Hispanic Asian Americans consistently had the lowest rates of obesity, with only 18% and 17% of Asian men and women having a BMI over 30 in the most recent survey period.

On the other hand, Mexican-American adults had some of the highest rates, with 51% of men and 50% of women with obesity. Similarly, 41% of non-Hispanic Black men had obesity, as did 57% of Black adult women.

“Although BMI is widely used as a measure of body fat, at a given BMI level, body fat may vary by sex, age, and race and Hispanic origin,” Fryar and colleagues wrote. “In particular, research suggests that health risks may begin at a lower BMI among Asian persons compared with others.”

The current prevalence of obesity in the U.S. is much higher than it was several decades ago.

In national data from the survey period of 1960-1962, only 13.4% of adults had obesity and 31.5% were considered overweight; less than 1% had severe obesity.

However, from the early 1960s to today, the rates of obesity steadily increased each decade, doubling from 15% in 1976-1980 to 30.9% in 1999-2000.

Since the turn of the century, the rise in obesity rates seemed to slow down a bit despite still increasing. For example, the only times that obesity rates actually fell in the past 60 years were in 2007-2008 and again in 2011-2012.

According to the 2017-2018 NHANES data on American children and adolescents, 19.3% of Americans ages 2-19 had obesity, and 6.1% of kids were identified as having severe obesity. Another 16.1% of U.S. children were overweight during the survey period.

At this time, the rates of obesity were highest among teens: 21% of those ages 12-19 had obesity, with the rates for teen boys slightly higher than for teen girls (23% vs 20%).

Similar to American adults, ethnic patterns emerged among kids. As for boys, the highest rates of obesity were seen among those of Mexican-American (29%) and Hispanic (28%) descent, whereas for girls, the highest rates of obesity were among Black (29%) and Mexican-American (25%) children and adolescents.

Also similar to adults, obesity in American kids followed a trajectory over the past several decades. In the 1971-1974 survey period, only 5% of U.S. kids had obesity, with only 1% of this subset having severe obesity; only 10% of kids were then overweight. From 1999-2000 through 2017-2018, there was a gradually increasing trend in age-adjusted prevalence of obesity among all children and teens. However, the trend appeared to be leveling off in the last few years.

Source References: Health E-Stats 2020 and Health E-Stats 2020

Highlights and Explanation of Findings:

According to 2017-2018 NHANES data, the obesity rate among American adults has increased by about 12% since 1999-2000.

The serious health risks associated with obesity include coronary heart disease, end-stage renal disease, and diabetes.

Of note, obese children tend to become obese adults. Pediatric obesity can lead to mental health issues and cardiovascular risk factors such as high blood pressure, high cholesterol, and diabetes.

Healthy eating and active living are encouraged to reverse the obesity epidemic. The Nutrition and Weight Status objectives for Healthy People 2020 support the benefits of eating a healthy diet and maintaining a healthy body weight. The objectives also emphasize that efforts to change diet and weight should address individual behaviors, as well as the policies and environments that support these behaviors in settings such as schools, work places, healthcare organizations, and communities.

Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco

Primary Source

National Center for Health Statistics Health E-Stat

Source Reference: Fryar CD, et al “Prevalence of overweight, obesity, and severe obesity among adults aged 20 and over: United States, 1960-1962 through 2017-2018” NCHS Health E-Stats; 2020.

Secondary Source

National Center for Health Statistics Health E-Stat

Source ReferenceFryar CD, et al “Prevalence of overweight, obesity, and severe obesity among children and adolescents aged 2-19 years: United States, 1963-1965 through 2017-2018” NCHS Health E-Stats; 2020.

Additional Source

MedPage Today

Source Reference: Monaco K “Over 73% of U.S. Adults Overweight or Obese” 2020.

urpoids ou obèses » 2020.