You really can. Losing weight is more difficult than gaining muscle, but you can succeed if you master the method. The gym has comprehensive conditions to make you slim down. Reducing fat, aerobic should be combined with anaerobic, aerobic is treadmill, dancing in gym, cycling in bicycle room, etc. Anaerobic is the exercise of equipment. If you don't understand, there will be a platform in the process of losing weight, that is, your body adapts to your running and can't lose weight.