I believe they receive one stripe for each 20 lbs. they gain after joining "the force."
Seriously,snacking to relieve boredom of sedentary jobs is a real problem,whether your spend 8 hours in a soft seat behind a dashboard and a radar gun or the same time in an office chair tethered by the telephone and computer.
The human body was designed to be active a good part of the time and lack of exercise is a downside of many jobs.