Obesity rates continued to rise last year in every state but one, said the authors, who based their analysis on figures from the Centers for Disease Control and Prevention.
More than a quarter of adults in 10 states - mostly those in the southeast - are now obese, while more than 9 million children - 15 percent - are overweight or obese.
Commissioned by the Trust for America's Health, a non-profit organization that campaigns for disease prevention, the report criticized the government's approach to the epidemic.
The US Department of Health and Human Services set a national goal of reducing obesity in adults to 15 percent or less by the year 2010 but the report questions how this target will be reached.
Some estimates say that almost three quarters of adults could be overweight or obese by 2008.
"We have reached a state of policy paralysis in regards to obesity," said Shelley A. Hearne, executive director of TFAH. "We need more and better data so we can make decisions to get out of the debate limbo in which we are stuck. We have a crisis of poor nutrition and physical inactivity in the US and it's time we dealt with it."
The authors call for a broad spectrum of responses, such as healthier school lunches with standards set above those of the USDA, subsidized gym memberships for Medicare recipients and pedestrian-friendly neighborhoods.
The food and beverage industry should ensure consistent nutritional labeling and a wider choice for consumers.
Media coverage of the report has once again raised the debate over responsibility for obesity - many believe it is largely the individual's responsibility - but the TFAH suggests that the epidemic is about more than weight.
"The American health epidemic is not just about obesity, but also poor nutrition and lack of physical exercise. Therefore US obesity policy should focus on ways to encourage healthy eating and exercise regimes for all people, not matter what their current weight may be," write the authors.
Approximately 119 million Americans, or 64.5 percent, of adult Americans are either overweight or obese. Estimates of the number of obese American adults rose from 23.7 percent in 2003 to 24.5 percent in 2004.