According to the latest statistics from the Centers for Disease Control and Prevention (CDC), approximately 34 percent of adults in the U.S. who are at least 20 years old are obese. Now, a new reports suggests that the obesity rate among adults will continue to increase in the coming years.

Researchers from Harvard University noted that the number of obese adults is not expected to decline until it reaches 42 percent or higher. Alison L. Hill, the study’s lead author, said that people have continued to gain weight over the last four decades and “haven’t gotten any better at losing weight.” The experts suggest that the obesity rate among adults will not decrease for at least another 40 years.

The researchers attribute a number of reasons as to why Americans are becoming increasingly overweight. This includes the spread of obesity from person to person and easier access to unhealthy foods.

Adults could eat healthier and nutritional foods to lower their risk of becoming obese. According to the CDC, a diet rich in fruits and vegetables is beneficial for an individual’s weight management and may also lower the chances of developing chronic diseases.