Is it true that you need to burn more calories than what you consume in a day in order to lose weight?

because ive been going to the gym. jogging and walking on the treadmill. and i burn like 320 calories in 25 mins and even more because i use some pills called cardio fire witch are suppose to turn your fat into energy in order to loose more weight while working out. i eat like 1200 calories a day. so am i not loosing anything or is that workout gone to a waste