There are signs that Americans overall are getting a grip on their expanding waistlines for the first time in decades. But before anyone becomes too optimistic, the flip side is a significant jump in Americans who edged into the worrisome category of extremely obese.
The question then, heading into a New Year filled with well-intentioned resolutions for weight loss, is which trend will prevail? Is there reason to hope that Americans are turning a corner on a major public health issue?
"Americans seem to have woken up to the fact that we've got a problem, and the leveling off in obesity rates is a very good thing," says obesity researcher Donna Ryan, a professor emeritus at the Pennington Biomedical Research Center in Baton Rouge. "But there is still lots of hard work to do to get people to healthier weights."
Recent government data showed that obesity among U.S. adults is continuing to level off after several decades of skyrocketing growth. In 2012, about 34.9% of the people in this country were obese, roughly 35 pounds over a healthy weight. That was not significantly different from the 35.7% who were obese in 2010, according to Cynthia Ogden, an epidemiologist with the National Center for Health Statistics, part of the Centers for Disease Control and Prevention.
Adults are considered obese if they have a body mass index (BMI) of 30 or greater. BMI takes into account height and weight. It measures body mass; it doesn't distinguish between fat and muscle.
A 5-foot-4 adult would be classified as obese if he or she weighed 174 pounds or more; a 5-foot-9 adult would fall into that category at 203 pounds or more.
At the same time, another disturbing trend is emerging: The percentage of people who are extremely obese, that is roughly 100 pounds over a healthy weight, rose from 2.8% in 1994 to 4.8% in 2004 to 6.3% in 2010, according to the CDC. A person is deemed extremely obese with a BMI of 40 or greater.
The prevalence of obesity increased dramatically in the 1980s and 1990s after being relatively stable in the USA from 1960 to 1980 when about 15% of people fell into the category.
Obesity may be leveling off, "but with more than a third of the U.S. population in this category, it's nothing to brag about," Ryan says. Many people who are obese or extremely obese "have or will have health problems because of excess weight," she says.
Obesity contributes to a long list of serious health problems including type 2 diabetes, cardiovascular disease, liver problems, degenerative joint disease, some types of cancer and a host of other health problems.
"You do not need to lose all of your excess weight to get important health benefits," says Samuel Klein, director of the Center for Human Nutrition at Washington University School of Medicine in St. Louis. "The metabolic complications of obesity, such as increased blood pressure, high blood triglycerides, abnormal blood sugar, and increased liver fat can improve with only a 2% decrease in body weight, and continue to improve with greater weight loss. This means obese people who lose a small amount of weight and are able to keep it off will improve their health, even though they are still obese."
Overall, about two-thirds of adults - nearly 155 million U.S. adults - are overweight or obese.
Doctors are urged to help tackle the obesity in this country as aggressively as they tackle high blood pressure, says Ryan, co-chairwoman of the committee that recently released obesity treatment guidelines for the Obesity Society, American Heart Association and American College of Cardiology.
The guidelines say there's no ideal diet for everyone, but doctors need to help obese patients figure out the best plan for them, whether it's a vegetarian diet, low-sodium plan, commercial weight-loss program or a low-carb diet.
Health care providers should encourage obese and overweight patients who need to drop pounds for health reasons to lose at least 5% to 10% of their weight by following a moderately reduced-calorie diet suited to their food tastes and health status, while being physically active and learning behavioral strategies.
The most effective behavior-change weight-loss programs include two to three in-person meetings a month for at least six months, and most people should consume at least 500 fewer calories a day to lose weight, the recommendations say.
The gold standard is an intervention delivered by trained interventionists, not just registered dietitians or doctors, for at least 14 sessions in the first six months and then continue therapy for a year, Ryan says.
If this kind of intensive therapy is not available, then other types of treatment, such as commercial weight-loss programs or telephone and Web-based programs, are good second choices, she says.
Diet alone is not recommended, the guidelines says. People should do moderate physical activity, working up to doing at least 150 minutes per week. They should also get behavioral counseling.
"Weight loss isn't easy -- it's hard work," Ryan says. "But the payoff for learning new behaviors to sustain a healthier weight is a big improvement on blood sugar control, blood pressure control and lipid control, along with more energy, better mobility, improved mood and a real bonus -- patients are likely to need fewer medicines and smaller doses."
Obesity over time
Percentage* of adults who were obese in:
*Note: Percentages are rounded
Source: National Center for Health Statistics, part of the Centers for Disease Control and Prevention