Answer – Belly fat is about hormones. What I mean by that is insulin and cortisol are hormones that work to build and store fat rather than utilize and burn fat. If you have belly fat, you have too much or too frequent release of them in your body.
The visceral fat around your organs responds to exercise because it is insulin sensitive. This is the fat under your muscles and around your liver and heart. This is the dangerous kind that we gain throughout a sedentary life and will contribute more to inflammation and eventually heart attacks.
Subcutaneous fat is the fat you can grab and the kind we mostly talk about when we say we want to lose weight. It’s around the belly and back, thighs, neck, and arms. This fat is more insulin resistant and does not respond quickly to exercise. Losing subcutaneous fat is more about diet than exercise.
When you eat food with sweeteners and carbohydrates in them, your body has to release more insulin than usual to manage the digestion of those foods. Insulin removes the glucose (it’s a sugar) that your body makes through digesting these carb-heavy foods by storing them in fat cells.
Insulin is inflammatory: you want to use as little as possible. When it is in your blood frequently or for long periods, it causes problems in your arteries, liver, and kidneys. It also makes you fat, both from sheer calories (storing the unused glucose) BUT ALSO from how it prevents the hormones that utilize fat from working. This is the piece that the “calories-in-calories-out” theory fails to account for.
With insulin high your metabolism is in anabolic mode. It is building. Your body won’t break down your stores of fat for fuel or use the fat you eat while insulin is high because the presence of insulin blocks metabolic breakdown and forces metabolic build-up. Then, since every cell needs fuel every second, the presence of insulin forces your cells to rely only on glucose for fuel rather than fat. That means you crave and get hunger pains and eat frequently.
Most high-carb eaters eat something like 5-20 times a day (even a sip of soda here, a few crackers, a piece of candy, etc). This frequent eating means insulin is always high which means you are not breaking down your fat stores for fuel or using the fat you eat (for you even fat gets stored, as well, though for low-carb eaters the fat gets used), which means your body pushes you to provide it more and more fast carbs. It’s a spiraling cycle. Relying on carbs for your primary fuel has other disadvantages, but this post is about belly fat.
When you experience prolonged stress (whether emotional or physical), your body releases cortisol to manage the need for more energy.
Cortisol does sort of the opposite of insulin: it’s catabolic, a hormone that breaks down and mobilizes energy rather than stores it because it’s the hormone your body uses when you need to run from a predator or fight for your life. Your body doesn’t know the difference between the stress you feel from a test day versus the stress you feel from a lion about to eat you. Your body just mobilizes fuel so you can act!
Cortisol makes FAST fuel–that means glucose, not the triglycerides from your body fat that can be used to fuel you in ordinary circumstances (because fat burning is a more complicated and time-consuming process). So cortisol makes fast fuel from places that give it easy glucose: your muscles and your liver.
Cortisol breaks down muscle to get its glycogen stores and to provide amino acids to your liver which creates glucose through gluconeogenesis. While it’s mobilizing fuel for quick action, cortisol is also shutting down nonessential functions: the production of sex hormones, bone and muscle growth, and your immune system.
So you can see that having high insulin and high cortisol is a double whammy of bodily destruction. Insulin is anabolic and adding fat and cortisol is catabolic and destroying muscle.
Both hormones are necessary for healthy function, but we’re talking about living with chronically high amounts.
Both hormones can create resistance to itself, as well, meaning your body has to produce more and more to get the same response; this is why you want to use only as much as you need to remain sensitive to the work of these hormones. The way to keep them low is to keep carbohydrate foods both low and infrequent and to keep stress both low and infrequent.
BTW stress includes things like too little sleep and too much exercise–cortisol takes away your gains! Lifting at gym is where you break down your muscles. Running on the road is where you break down your muscles. They grow when you REST and SLEEP. If you have fat and you’re a low-carb eater and exercise regularly, adjust your sleep and stress and recovery time. It’s likely cortisol!