This is really more about obesity. Youre more likely to be obese if you have a lower activity level, but if you eat properly youll still be fine. I hate when people use these studies and say, "Oh, this must mean sitting causes obesity." No, that is the wrong conclusion. Lower activities and obesity has a positive correlation. However, there are probably many many other factors that contribute to poor health these percentages arent able to calculate.
Not to deter from exercise, but do it for the right reasons. Dont do it because some image on the internet said you would die if you dont.