Viewers who put themselves through 90 minutes of adrenaline-pumping terror can use up as much as 113 calories, close to the amount burned during a half-hour walk and the equivalent to a chocolate bar.
The movie top of the list of calorie-burners was found to be the 1980 psychological thriller The Shining, with the average viewer using up a whopping 184 calories.
Jaws took the runner-up spot, with viewers burning on average 161 calories, and The Exorcist came third, with 158 calories.
The University of Westminster study measured the total energy expenditure of ten different people as they watched a selection of frightening movies.
Scientists recorded their heart rate, oxygen intake and carbon dioxide output - and discovered the number of calories used increased by on average a third during the films.LINK