"Exercise doesn’t really lead to weight loss, just healthier body parts."

Do you think I'm just shilling for Big Exercise again? :-)

The formula is pretty simple: calories in - calories out = fat.
You can lose weight by diet restriction alone. You can lose weight by exercise alone. The two together are unbeatable. The important thing is good health is more than just weight, however. Exercise is good for your health even if you don't lose a pound. It would be interesting to ask your doctor on one of your many visits whether diet or exercise is more important. I predict the answer will be emphatically that both are important. Exercise does things for your cardiovascular system, brain, and joints that diet can't touch.