Re: Should I Re-Start Aikido?
Personally I agree that doing aikido won't necessarily take weight off -- most people need to change their diet for that, and you may find other physical training is needed to help make sure you keep/gain muscle and lose fat, to strengthen your joints, etc, and I'm sure you would need to limit yourself for a while for safety reasons, particularly when it comes to ukemi (which is the kind of thing you may remember how to do without your body being up to it). But lots of beginners take a long time to learn ukemi, so to me that's not unique.
But personally, for me I have always found that having something that I do on a regular basis that I love to do and want to be able to do better is the best motivation and constant reminder to do other (more boring and less intrinsically rewarding) kinds of things that will help me do the things I love better. When I started aikido I was skinny but weak and very quickly tired. Many things I wasn't physically capable of then that I can do now, I did only beginner classes, only two a week, and people were very gentle with me, but I loved it. Partly aikido helped me get in shape some (esp cardio) but it also gave me a lot of new reasons and reminders and rewards to push me to get healthier and fitter. I've found the same with other activities I like for themselves. For me it's important to do something you can get passionate about.
You may find the same. (or you may not)