I love this one. I hear this question all the time. let me start off with. It has very little to do with the abdominal crunch. Flat stomachs are truly made in the kitchen & when you up that cardio. I know everyone hates cardio but you Have to do it to lose that extra inch or two of ‘insulation’ off those target areas.
A strong core is always essential, no matter how insulated you may or may not be. Core strength is a key player in posture. Helping with lower back, shoulder and hip problems. It is also needed for just about all exercises you perform. (if you want to do them correctly)
Cardio is normally the first way to slim everything down in general. Try to push yourself everyday. There is no point in having an enjoyable carido session. You need to be going beyond what you are comfortable with in order to achieve that extra burn! The more calories you burn the better your chances of losing weight.
That being said. You can never out exercise a crap diet. So start either counting calories, cutting out the booze, stop gorging at 10pm or do whatever it is that you need to do to start eating clean. (non processed….) Remember every day is a new day to give it another try.