After years of rising obesity rates in the United States, recent statistics show the rates may have steadied. But that may not be enough, according to a new report released on Monday - it estimates about 42% of the U.S. population will be obese by 2030.

The report suggests an additional 30 million Americans will be obese in 18 years. This would cost an additional $549.5 billion on medical expenditures, according to the report in the American Journal of Preventive Medicine.

“If you could keep the obesity rates at today’s level, you would save $550 billion,” said Eric Finkelstein, lead author of the report.

About 35% of U.S. adults are obese today, according to the Centers for Disease Control and Prevention.



The obesity projections were released at the CDC's Weight of the Nation conference, which is focused on preventing this growing health problem. A four-part HBO documentary with the same title begins airing next week.

Finkelstein and co-authors estimate that 11% of the population will be severely obese by 2030. Severe obesity is defined as a body mass index over 40 or being roughly 100 pounds overweight. Obese people have shorter life expectancies and greater lifetime medical costs, “suggesting that future healthcare costs may continue to increase even if obesity prevalence levels off,” wrote the authors.

“Those individuals have much greater risk of early mortality, diabetes, heart disease,” said Finkelstein. “They’re much, much more expensive and they’re on the rise, partly because 50 years ago, it was really, really hard to weigh that much. You’d have to eat all the time.”

But modern convenience has made an abundance of cheap and easy calories available, he added.

The authors calculated the future obesity and severe obesity prevalence based on population factors such as gender, age, race, ethnicity, employment data and recent trends.

Prior estimates assumed the level of obesity would continue unabated.

“We thought those estimates were too high,” said Finkelstein, health economist at Duke Global Health Institute. “A better way would be to look at underlying factors of obesity like fast food prices, price of alcohol, internet access, changing demographics.”

They also looked at variables such as the cost of healthy food, grocery prices, the number of fast food restaurants and annual household income.

The projections were based on data from a 2008 study of adults. It did not include children - where one out of three is overweight or obese.

“We just looked at adults,” said Finkelstein. “The reality is obese kids almost certainly become obese adults. Our estimates may be conservative.”

“We’re almost surely wrong in our forecast,” he added. “That’s the thing about forecasts - they are guesses. This is our best guess. The world changes, if new drugs or technology comes out, if the government comes out and makes major changes, lots could happen. If in fact we’re wrong and obesity rates are less, I’d be happy.”

Anti-obesity efforts such as recreational facilities, better urban design, work site health promotion, new drugs and technologies could help, wrote the authors.