Medical scientists from the University of Birmingham are actively countering the theory that people can be simultaneously overweight and medically fit, presenting new research that reinforces that obese people are at a far greater risk of developing cardiovascular disease than people of a normal, healthy weight.

Researchers claim that the term ‘fat but fit’ is a fallacy that spurs the spread of obesity, a global public health epidemic. The study—presented at the European Congress on Obesity in Portugal—assesses the medical records of 3.5 million people in the United Kingdom between the years 1995 and 2015, in order to evaluate the legitimacy of the theory ‘fat but fit.’

Previous medical research suggests that obesity can have little impact on a person’s susceptibility to various harmful diseases, if they are considered to be otherwise medical healthy. Yet the research, which consistently tracked obese but “metabolically healthy” people, found that they were still at a significantly higher risk of developing diabetes and other heart-related conditions.

Specifically, the study found that obese people were 50 percent more likely to suffer from coronary heart disease, and between 7 and 11 percent more likely to develop cerebrovascular disease and peripheral vascular disease. The United Kingdom’s largest funder of cardiovascular research, The British Heart Foundation, has stated that this research will help to dispel an ‘age-old myth.’

The data further estimates that approximately 28.1 percent of adults in the U.K. qualify as clinically obese, with a Body Mass Index greater than 30. In the United States, the statistics rise to approximately 66 percent.