On my end, it's been about 4 years since I've trained consistently or done regular martial arts and gymnastics... but, I've missed it, and as of a few weeks ago I'm getting back into it. I agree with Taucer - push yourself, but don't kill yourself.
As to the diet, a few simple rules to follow will make a HUGE difference:
1. Avoid sugar. Sodas, candies, sweets, etc, just avoid it. Get the sugar-free versions of whatever you can that you still feel you need to eat.
2. Avoid breads and potatoes. Lots of starch and carbs that really don't do a lot nutritionally there... just avoid it, and you won't have to work off that extra fat. Try hot dogs without the bun, for example.
3. Lots of meat, lots of veggies. Period.
Incidentally if any of y'all are in the Syracuse area, I'm thinking of starting up a little informal Capoeira group there for training, come Spring of 2012 - http://www.syracusecapoeira.com. I still have to work a lot of rust out of my own system before I'll personally be ready, but it could be a lot of fun.
Actually, it's not really about avoiding carbs - it's just cutting down on portions in general. Avoiding candy & soda and the ilk is of course good. If you exercise regularly though, you need the carbs, or your body then starts to become more taxed as it tries to break down fat & as a result you do less and get less from workouts. Contrary to popular belief, unused carbs don't convert to fat, but glycogen for ready conversion back into sugar for the body to use. It is very important to replenish glycogen after workouts so you can get the max out of your next workout!
Otherwise I agree though .