Cortisol and Insulin: Partners in Crime When It Comes to Belly Fat

You may not like the tummy fat that jiggles when you try to zip up your jeans, but it’s not the worst kind of belly fat from a health standpoint. The kind you really have to worry about is deeper fat that lies beneath your abdominal muscles and increases the risk of health problems like type 2 diabetes and heart disease. This form of fat called visceral fat becomes more common with age, especially around the time of menopause in women and in men as they approach the age of 40. There are two primary hormones that play a role in visceral abdominal fat and reining in these two belly-boosting hormones can help control a deep belly fat problem. These two hormones are insulin and cortisol.

Insulin and Cortisol: How They Contribute to Visceral Fat

Insulin is a hormone produced by the pancreas that regulates how your body handles glucose. When you’ve just eaten a meal, it helps to ferry glucose into cells where it can be stored. It also helps muscle cells take up amino acids, which is important for muscle repair after a workout. In addition, it increases the synthesis of lipids and prevents the breakdown of stored fat to be used for energy. Insulin also has other functions that you may be less familiar with. It encourages cells to take up potassium and increases blood flow through arteries by relaxing blood vessel walls.

Insulin’s Partner in Crime: Cortisol

Cortisol is produced by the adrenal gland, a gland that lies just above the kidney. It’s frequently dubbed the “stress hormone” because it rises during times of mental and physical stress. Some common conditions that increase cortisol levels are prolonged exercise, starvation, calorie restriction, and sleep deprivation. One of its main functions is to maintain blood glucose levels in response to stress. One way it does this is by promoting gluconeogenesis, a process by which the liver makes glucose from amino acids. To supply the liver with the amino acids it needs to make glucose, it encourages the breakdown of muscle tissue, which isn’t a good thing when it comes to health or body composition. Who wants to lose more muscle mass as they age? In addition, it suppresses the immune system and promotes bone breakdown – also not a good thing from a health standpoint.

So why are insulin and cortisol such a bad combination when it comes to visceral belly fat? Cortisol has a somewhat contradictory effect on fat stores. It activates a hormone called lipoprotein lipase that stimulates fat storage, but it also increases the activity of hormone-sensitive lipase, a hormone that breaks down fat. Taken alone, these changes might not be so bad since the fat storage effects of cortisol would be canceled out by its effect on fat breakdown. But then insulin enters the picture. Insulin promptly turns off cortisol’s effect on hormone-sensitive lipase, and the breakdown of fat grinds to a halt. Now, cortisol’s effect on fat is to promote its storage, and it does so primarily in the deep abdominal region to form visceral fat.

To Reduce Visceral Fat, Reign in Insulin and Cortisol

To deal with the belly fat problem, you need to lower levels of these two belly-plumping hormones. The best way to reduce insulin levels is to eliminate processed carbohydrates and sugary foods that send blood sugar and insulin levels into overdrive. Skip the French fries, and choose fiber-rich carbs from vegetables and whole grain sources. The fiber in these foods helps to reduce insulin spikes. Another way to reduce insulin levels is to engage in a regular, moderate to high-intensity exercise program that includes both strength-training and aerobics. High-intensity exercise boosts the release of growth hormone, which helps take a bite out of belly fat.

But that’s only one part of the equation. Having too much cortisol floating around in your body will do you no favors either. To lower cortisol levels, eat regular meals that contain lean protein and fiber-rich carbs to maintain blood sugar levels, and don’t overly restrict calories. Keep exercise sessions short and intense. Some research shows that prolonged endurance exercise boosts cortisol levels. Get at least seven hours of sleep a night. Sleep deprivation raises cortisol levels. Make sure you’re getting enough B vitamins, vitamin C and magnesium in your diet since these vitamins and minerals help to lower cortisol levels. Lastly, limit caffeine, and find some effective ways to manage stress such as yoga, tai chi or meditation.

The Bottom Line?

Insulin and cortisol – they’re a bad pair when it comes to visceral belly fat. Take steps to keep these pesky hormones in line, and keep your waistline trim.

References:

The Journal of Clinical Endocrinology & Metabolism March 1, 2005 vol. 90 no. 3 1466-1474.
International Journal of Obesity 24: S77-S79, 2000.

Related Articles By Cathe:

Metabolic Aging: How Key Hormones Are Affected by Aging

Factors That Can Increase Your Cortisol Level and Make It Harder to Control Your Weight

Why You’re Lean but Still Have Too Much Belly Fat