The United States recently hit the pause button on rising obesity levels among adults after nearly a generation of ever-expanding waistlines, research indicates.

Now the questions are whether the slowdown is a fluke or represents a turning point in the fight against fat, and what can be done to continue the trend.

Overall, the national share of obese adults remained at 35.7 percent in 2012, about the same as the previous year, according to a Trust for America’s Health report based on Centers for Disease Control and Prevention data. If overweight adults are added to the mix, 69 percent of Americans 19 and older are carrying extra pounds.

It is a level that alarms public health officials, even though an August report by the CDC found that obesity rates for low-income preschool children in 18 states have declined. The share of young people ages 2 to 19 considered obese is still 17 percent. And more than 31 percent of all U.S. children are overweight or obese.

On Jan. 7, the Institute of Medicine convenes a roundtable devoted to finding solutions to obesity. The panel, which is funded for three years, will not make formal recommendations to Congress but it is charged with identifying best practices and effective ways government, business and communities can change the nation’s food, exercise and health habits.

The members come from the areas of academia, civil rights, fitness and exercise, government, public health, foundations and the food industry. They will be able to set up smaller groups, some that include nonmembers, to do surveys, commission white papers or dissect successful anti-obesity efforts in communities.

Congress has a mixed record on food and fat issues. In 2009, some lawmakers and nutrition advocates pressed unsuccessfully for a tax on sugary drinks, primarily soft drinks, to reduce people’s consumption. The money raised would have provided a small revenue stream for health care expansion.

Democratic Sen. Tom Harkin of Iowa and Rep. Rosa DeLauro of Connecticut got a requirement into the health care law (PL 111-148, PL 111-152) that chain restaurants with more than 20 locations must post calorie counts for their goods.

But other lawmakers have pushed back against tougher nutrition standards for federal breakfast and lunch meals that emphasize fruits and vegetables and reduce fat and sugar intake. They say the standards are impractical, expensive and leave some athletic kids hungry.

In 2011, House members responded to food marketers and manufacturers that were opposed to an interagency working group created by President Barack Obama’s executive order. The group had been told to produce preliminary recommendations to limit advertising and marketing of foods that did not meet suggested nutritional standards. Appropriators included a policy rider in an omnibus spending bill (PL 112-74) that required the working group, which was led by the Federal Trade Commission, to assess costs and benefits of possible regulations. The rider effectively put the recommendations on hold, where they remain.

Lawmakers such as Rep. Tom Marino, R-Pa., want the federal government to police its food aid programs for the poor. In 2013, Marino energized opposition from food manufacturers with his bill (HR 1752) to require that the Agriculture Department track the kinds of foods people bought with their monthly benefits through the Supplemental Nutrition Assistance Program, formerly known as food stamps. The department would publish detailed lists of the purchases.

Marino lost a 79-346 floor vote in June on an amendment to the House farm bill (HR 1947) that would have required the Government Accountability Office to monitor a nine-state pilot project to collect SNAP purchase information. Marino said taxpayers needed accountability from the nearly $80 billion-a-year program. Opponents such as Rep. David Scott, D-Ga., called it food surveillance.

Lisa Gable, an IOM roundtable member and president of the food industry’s Healthy Weight Commitment Foundation, sees the new panel as an opportunity to build on existing partnerships with schools, parent-teacher associations and governments. Gable said some people remain skeptical about the food industry’s interest in reducing obesity, but she said the companies active in the foundation have found that reduced-calorie foods make money.

Gable said the roundtable’s mission is to “look at collaboration.” Many anti-obesity programs have been launched in the past five years, some with positive impacts, she said.

“But until those programs are aligned in a manner in which they can work together cost effectively, it’s not going to be sustainable,” she said.

Still, some in the advocacy world see the U.S. food industry as a contributor to the nation’s weight and health woes because of sugar, fat and other ingredients in readily available processed foods.

Jeffrey Levi, executive director of the non-profit Trust for America’s Health, welcomes the IOM panel’s creation. Levi, a co-author of the August “F as in Fat” report that found stable adult obesity rates, is among several people scheduled to address the group. He said he will stress the need to resist the temptation to find a magic bullet to hold the line on obesity.

The trust believes efforts such as improved federal school meal nutrition rules and local government and community programs focused on walking and biking to increase exercise are making inroads on obesity.

But there has been a “painful history” in public health of pulling back when progress is seen, “when it is actually the moment to be doubling down,” Levi said.

The report by the trust and the Robert Wood Johnson Foundation found that 49 states and the District of Columbia held steady in the percentage of adults with body mass index readings of 30 percent or higher. Arkansas was the exception, with a slight increase in adult obesity.

Levi said he thinks federal agencies should give state, local and community officials greater flexibility in how they use federal funding to achieve healthy goals. For example, Levi said, bike lanes should be considered a worthwhile transportation investment because they encourage physical activity.

Advocates for mandating that governments spend 10 percent of federal transportation money for bike paths and other uses lost ground in the 112th Congress. Sen. Tom Coburn, R-Okla., won his fight to ease the requirement in a transportation reauthorization bill (PL 112-141).

“I think there is a broad consensus that obesity is a health problem but there is disagreement about the role of government,” Levi said.

Although the IOM roundtable will make no formal recommendations to members of Congress, IOM consultant William H. Dietz said the panel could make significant contributions with practical suggestions.

“There’s an awful lot of stuff around about what should be done but very limited information on how it should be accomplished,” said Dietz, who is part of the roundtable.

The roundtable’s areas of interest will be fleshed out over the course of several meetings and under the direction of Chairman Bill Purcell, an attorney and former mayor of Nashville, Tenn., as well as the vice co-chairman Russell R. Pate of the University of South Carolina and vice co-chairwoman Mary Story of Duke University.

Dietz brings to the process 20 years of research and clinical experience in Boston working on childhood obesity and several years of work on child and adult obesity with the CDC. He said state and local governments along with communities are trying a number of approaches to reduce obesity, particularly in children.

But Dietz said it is not easy to determine how effective the efforts are. For example, he said, there was a decrease in child obesity levels following a national drop in consumption of pizza and sugary drinks. Since the change in food habits was uneven across states and communities, Dietz said it indicates that other factors may have been involved.

The roundtable’s ultimate goal is “to accelerate progress on obesity prevention and control,” Dietz said.