Okay, let us get one thing out of the way. You CANNOT spot reduce! You cannot simply get a smaller waist and not expect other parts to reduce in size. How that reduction happens is largely genetic, but ultimately you need to lose body fat, and your genetics will unfortunately decide how and where you lose it from.
Extensive body composition change is effectively like going to war. You are heading into battle against what your body wants to do, which is stay the same. This process is called homeostasis.
It is your body's aim to keep everything the same, which is why, when we cut calories too drastically, it panics and holds on to bodyfat, rather than drop weight. The hormonal reaction to massively decreased calories is an uphill battle, while carrying a 50 tonne weight on your back, because not only does your body refuse to release the excess fat, it will burn muscle first as its an easier fuel source for it to access. It will also decrease leptin levels, so you dont get a feeling of being sated after eating and it is increases your ghrelin levels, aka the hunger hormone, as it pushes your body to replace the missing calories.
So where does the mummy tummy and belly fat aspect enter? Well another outcome of too few calories, coupled with excessive exercise, is a higher release of cortisol in the body. A stress hormone that causes excess fat to accumulate around the stomach, protecting the main organs for survival. Which is why, even when you think you are doing everything right, the results still seem to come too slowly or not at all.
So how do we fix it? Well, first and foremost, you have to cut calories, not so much that we trigger the hormone responses i just listed, but enough to cause a tiny deficit. Then we add in exercise, that will make that deficit just the tiniest bit bigger. The intensity of that exercise is also very important. Which is why, I always discuss food with clients when working towards a goal. Exercise is a must for a more taught body, there is no getting around it. Can you lose weight without exercise? Yes, definitely!! Will you get that toned, tight physique without it? Unfortunately not.
Remember though, it doesn't always have to be punishment. My proudest moments is when I think of all the clients i have helped through out the years, but what makes me proud is not just the results they get, but the love of exercise. The confidence they have even years down the line. Helping someone lose weight is easy, motivating them and showing them that a healthy and exercised filled lifestyle is something anyone can achieve and can both be fun and rewarding, now THERE is what matters. And just for the record...a crunches do very little unless everything else is in place, so save your back, cut your calories and do a few squats!!