Obese adults in the U.S. have worse heart health and a higher risk of type 2 diabetes today than in the late 1980s, a new study suggests.

"For those who are obese and have (high) blood sugar or are just obese, they should try a more intense approach to control their weight and blood sugar levels so that they have a lower risk of cardiovascular outcomes," said Dr. Fangjian Guo, the study's lead author from The University of Texas Medical Branch in Galveston.

As reported in the Journal of the American Heart Association, the researchers used data collected from 18,626 obese adults between 1988 and 2014 through the annual National Health and Nutrition Examination Survey.

Overall, the researchers saw decreases in blood pressure and cholesterol levels during that time. However, they found increases in hemoglobin A1c, which reflects blood sugar level over the past several months. Higher levels of A1c suggest worse blood sugar control and possibly diabetes.

Over the course of the study, the proportion of people with no risk factors for heart disease - no high blood pressure, no high cholesterol and normal blood glucose control - remained steady at about 15 percent.

More on this...

But by the end of the study, the proportion of people living with only one or two risk factors for heart disease had dropped. In 1988, 70 percent had one or two risk factors, versus about 62 percent by 2014.

Instead, the proportion of people with all three risk factors for heart disease had gone up - from about 16 percent in 1988 to about 22 percent in 2014.

Guo and his coauthor Dr. Timothy Garvey of the University of Alabama at Birmingham say the findings show heart health has worsened and the risk of type 2 diabetes has increased among obese adults since the late 1980s.

Type 2 diabetes develops when the body can't produce or process enough of the hormone insulin to remove sugar from blood.

Obese adults with high blood pressure, high cholesterol and high blood sugar should be targeted to stem the rising rates of type 2 diabetes, the researchers add.

The U.S. Centers for Disease Control and Prevention has an online tool for calculating healthy weights, here: http://bit.ly/2aajlt2.

Guo said it will likely take many years for these rates to reverse even if action is taken, because health problems from obesity often pop up later in life.