A concerning new study reveals Americans are continuing to put on the pounds, despite efforts to fight the growing problem.

The new estimates show more than two-thirds of Americans are either overweight or obese, the JAMA Network Journals reported. Obesity is linked to a number of serious chronic health conditions that could be avoided with weight control.

To make their findings, a team of researchers looked at data from the National Health and Nutrition Examination Survey, which took place between the years of 2007 and 2012. The data included medical information on 15,208 men and women 25 or older, which is a sample representative of more than 188 million people.

The findings revealed 39.96 percent of men (36.3 million) and 29.74 percent of women (almost 28.9 million) were overweight; 35.04 percent of men (31.8 million) and 36.84 percent of women (nearly 35.8 million) were obese.

These numbers mean 75 percent of men and 67 percent of women over the age of 25 are now overweight or obese, the Washington Post reported. This a huge leap from 20 years ago, when it was estimated that 63 percent of men and 55 percent of women were overweight or obese.

"Population-based strategies helping to reduce modifiable risk factors such as physical environment interventions, enhancing primary care efforts to prevent and treat obesity, and altering societal norms of behavior are required," the authors concluded.

The findings were published in a recent edition of the journal JAMA Internal Medicine.