Some people eat foods and do not gain weight while others do with the same diet.does this mean that a faster metabolism may mean a quicker heart rate?

Not usually: There are many factors that affect weight gain and three that really are out of our control are age, gender and genetics. The type of food, activity level, sleep and stress also play huge role and are under our control. It is possible to start looking at genetic variations fairly easy that may help patients pick the best diet for them.