A considerable proportion of obese teenagers become severely obese adults by the age of 30, with a Body Mass Index (BMI) of 40 or more. The comment by friends or relatives that the boy will grow out of his puppy fat is a myth – most likely, as an adult he will be more severely obese. Researchers from the University of North Carolina at Chapel Hill wrote in JAMA (Journal of the American Medical Association) today that the risk for an obese teenager to become even fatter as an adult is especially high among females, and African-American females above all.
The authors explained that severe obesity carries with it a serious and real risk of life-threatening complications.
They wrote:
In 2000, an estimated 2.2% of adults, or 4.8 million individuals, were severely obese, with a disproportionately higher prevalence in women and racial/ethnic minorities. Yet, few national studies track individuals overtime to understand the progression of obesity to severe obesity.
Understanding which individuals are at risk of severe obesity is essential for determining when interventions would need to be implemented to prevent obese individuals from progressing to severe obesity. Although observational studies have reported that the prevalences of overweight, obesity, and severe obesity have increased in recent years, individuals who are obese early in life have not been studied longitudinally to determine their risk of developing severe obesity in adulthood.
Natalie S. The, Ph.D. and team set out to find out what body weight outlook was like during adulthood for obese teenagers. They examined data on 8,834 people aged 12 to 21 years who had enrolled in 1996 in the second wave of the US National Longitudinal Study of Adolescent Health. They were all followed-up until adulthood up to the age of 27 during the third wave, and in the fourth wave until they were 33 years old. The investigators gathered data on each person’s height and weight.
1% of the teenagers were severely obese in 1996, of which 70.5% continued to be severely obese as adults. From 1996 to 2009 – from adolescence to adulthood – the investigators identified 703 new cases of severe obesity; a total incidence of 7.9%. They also discovered that a considerably higher percentage of adults with severe obesity were obese as teenagers. They also report that racial/ethnic minorities were more likely to be obese.
The authors wrote:
A substantial proportion of obese adolescents became severely obese by their early 30s, with significant variation by sex. Among individuals who were obese as adolescents, incident severe obesity was 37.1 percent in men and 51.3 percent in women. Incident severe obesity was highest among black women at 52.4 percent. Across all sex and racial/ethnic groups, less than 5 percent of individuals who were at a normal weight in adolescence became severely obese in adulthood.
The investigators analysis, after taking into account several factors, found that adolescents with obesity were much more likely to become severely obese adults compared to normal weight adolescents, and even compared to overweight but not obese adolescents.
The authors wrote:
The clinical implications of these observed trends are concerning given the comorbidities and chronic disease associated with severe obesity. Findings highlight the need for interventions prior to adulthood to prevent the progression of obesity to severe obesity, which may reduce severe obesity incidence and its potentially life-threatening consequences.
JAMA. 2010;304(18):2042-2047. doi:10.1001/jama.2010.1635
Written by Christian Nordqvist