In terms of losing weight, I'd say that doing a combination of both can both help you lose weight but also become a bit more lean. I tend to do sessions where I work on various sections of the body in the weights (as having more muscle helps burn that fat) and then I end all sessions with a HIIT one where I can polish off those stubborn calories!
From 150 pounds I am now down to 142. All I did was to lessen my food intake and also observed the time that I eat. No more extra snacks and I also lessened the soda intake from 3 cans daily now I am drinking only once a day. I guess I am successful in that kind of diet although I do my regular exercise of 40 push ups.
I have struggled a lot when it comes to the weight loss. I think it takes some dedication and also change in diet for the diet to properly work out. For me so far there seems to be no way to find out if the weight loss can work out in such context.