Brief Answer:
Diet and exercise...
Detailed Answer:
Hi,
The most effective and safe method to loose weight is through diet and life style change.A customized diet prepared by a dietician will benefit you. In addition, cardioexercise which include swimming, cycling, jogging and thread mill along with muscle building exercises should be included as part of life style.
These changes will gradually help you loose weight.
Hope this helps. Let me know if you need clarifications
Regards