As US obesity epidemic grows, new study shows who is gaining weight over the last decade

The article, published in the Journal of Obesity, looked at the long-term weight gain of more than 13,800 U.S. adults -- a rare data point unearthed in obesity research. They found that more than half of American adults in the study gained 5% or more body weight over a 10-year period. What's more, more than a third of American adults gained 10% or more body weight and almost a fifth gained 20% or more body weight.

"The U.S. obesity epidemic is not slowing down," said study lead author Larry Tucker, a BYU professor of exercise science. "Without question, 10-year weight gain is a serious problem within the U.S. adult population."

Study participants were selected randomly as part of the National Health and Nutrition Examination Survey, an annual survey that examines a nationally representative sample. NHANES is a CDC-sponsored series of studies that began in the early 1960s and became a continuous program in 1999.

Using the NHANES data, the study also found that 10-year weight gain was significantly greater in women than in men, with women gaining about twice as much weight: 12 pounds on average for women compared to 6 pounds for men. Weight gain also differed across races, with Black women experiencing the greatest average weight gain over the 10-year period (19.4 pounds) and Asian men experiencing the least (2.9 pounds).

As far as age goes, the greatest gains in weight were found in young and middle-aged adults; less weight is gained as age increases. According to the data, on average Americans gain the following weight:

• 17.6 pounds between their 20s and 30s
• 14.3 pounds between their 30s and 40s
• 9.5 pounds between their 40s and 50s
• 4.6 pounds between their 50s and 60s

If adults gain the average amount of weight during each decade of adult life, they will have gained more than 45 pounds, which would push many of them into the obese category. According to the Department of Health and Human Services and the CDC, 42.4% of U.S. adults are currently obese. That's up substantially from the 30.5% measured in 2000.

"In roughly 20 years, the prevalence of obesity increased by approximately 40% and severe obesity almost doubled," Tucker said. "By knowing who is more likely to become obese, we can help health care providers and public health officials focus more on at-risk individuals."