When I started losing weight via Paleo, I made a point to see how many calories I needed to lose based upon my height, weight and activity:
Exercise in any form is beneficial and would help you meet your goals. I would think that even working with lighter free weights or just walking (I don't know if your knees can handle long walks or not) would definitely assist in burning up some calories.
UPDATE: Since I posted this answer, I have taken up Intermittent Fasting and have become a quick convert. The first day or two of attempting it was hard (I would only go 10-12 hours) but now have gotten up to around 16 hours of fasting. I have made more progress in a shorter amount of time from this without feeling any ill side-effects. I recommend trying it for a short amount of hours and working your way up to a longer amount of time.
I'll also say that not eating in the late evening and then going to bed helps tremendously. I usually eat something at 8p at the latest, and then usually don't eat again until around 1 the following day. I will, however, drink water or a cup of black coffee in the morning.