Yeah I was thinking if you are doing cardio and eating less calories you lose weight and while weight training you are getting stronger and more defined.
I'm sure people on here know more than me though if I knew about it I wouldn't be a fat ass 
Just as a thought - but a fat person eating the same amount of calories as usual could still experience a calorific surplus if his body started converting bodyfat to energy (glucose) at an accelerated rate due to changes in his activity levels. For really out of shape people even a small amount of exercise can give a massive metabolic boost. For some people even jumping jacks can be a hypertrophic exercise.
Just a thought though, i have no idea if any studies have been done on it.