It is doable, but I am concerned about the methods you may use to attain this goal. Please be careful not to endanger your health in this process. The end goal is to make yourself feel better. not inflict pain. The componants of your plan should be as follows.

Diet

Low carb and low in saturated fats, reasonable amount of protein( actually needed to keep you satisfied) and fruits and veggies. Stay away from processed meats (deli ham, bologna, hotdogs) if you can, these have a lot of sodium which causes water retention. Moderate amounts of Green Tea also help with metabolism.

Exercise:

Combine cardio and light weight training. The two kinds of exercise work hand in hand to speed up your metabolism and burn fat and excess carbs.
Also yoga and Tai Chi are excellent support exercises. Tai Chi is great for maintaining wellness and energy level, yoga will improve flexability and coordination.

Stay away from Fat loss pills, and other gimicks, these are a waste of money and are no substitute for will and discipline.

Follow the above and you should find a healthy way to acheive weight loss combined wih good muscle tone and joint health.