Some ads claim to help you with the cortisol in your system which magically causes all fat to gather up in your tummy. What is this all about?
First, let's start with the cortisol. When your body has a stressful situation, it naturally releases adrenaline and cortisone. These two hormones help to increase your heart rate, kick up your breathing, get your blood pressure pumping. These things help you, in an evolutionary sense, run away from the wolves or climb that tree to escape the lion. In addition, cortisol makes you really hungry - especially for sweet things. This also is intended to make sure instant energy gets into your system, to fuel your defensive actions.
The problem is that in modern times, it's usually not lions or wolves that cause your stress. It's usually an angry boss or screaming child. So you have a reaction that has you reaching for sugary things - and then all that food isn't used for running, it turns right into fat.
OK - so being flooded with cortisol makes you crave sweets, and if you eat tons of "real sugar" sweets vs diet sweets, you then have lots of sugar flooding your system, which your body will turn into fat if you're sitting still while you do this. But why would all this fat migrate into your belly?
The key is in the fat types in your body. There isn't just one type of fat everywhere, just like how different muscles in your body are laid out differently. Yes, there's the "fluffy" fat you find in your butt, for example. But there's a different kind of fat - visceral fat - which is a "padding" layer that surrounds all of your vital organs. While the fluffy fat near your outside is a storage system for excess fat, that visceral fat around your organs helps to keep them protected and safe.
Some studies seem to indicate that cortisol specifically increases visceral fat - but others show that this isn't true. Most researchers feel that the main thing that cortisol does is make you eat more sugary sweets - and therefore you get heavy. There are plenty of people who get stressed - and flooded with cortisol - and lose weight. So it's not just the cortisol itself that does it, it's how you choose to react to it in your system.
As far as cortisol blockers, that's really not the solution. Stress causes a *ton* of problems for your body - not just the sweet desires. It reduces your immune responses, it compromises your health. Don't just try to block one part of it. Take steps to handle the entire stress situation, for your own health.