Yoga centers on
building core strength, breathing and relaxation. It can help you build
muscle, lose weight and regain lost movement. You can get yoga dvd's relatively inexpensively at discount department stores, or google "yoga" and you can watch all types of videos, showing you how to do certain poses. Get your doctor's okay.
For diet, make sure you eat mostly veggies, and add in lean protein, low/no fat dairy, nuts, seeds and "good" fats.