Stress Got Your Metabolism Down?

I'm sure you've heard of the fight-or-flight response, and you probably know that it's the way your body reacts to danger or stress. But do you know what the fight-or-flight response is? You guessed it: It has to do with hormones.

When you're faced with a danger, your adrenal glands release three hormones: norepinephrine, epinephrine (also known as adrenaline), and cortisol. Norepinephrine and epinephrine cause several changes to help you survive the danger, including a pause in insulin release so you have lots of blood sugar available for energy, an increase in heart rate and blood pressure, and a suspension of your appetite. After the danger has passed, cortisol tells the body to stop producing norepinephrine and epinephrine and stimulates your appetite again.

This response evolved to help people deal with short-term survival situations, like an attack by a predator. The trouble is, it occurs in response to all stressors, including the deadlines pummeling you at work and the traffic that drives you crazy. When stress is always present, your body can't get rid of the excess cortisol built up in the blood. That cortisol just hangs around, causing lots of trouble: It turns young fat cells into mature fat cells that stick with you forever, and increases your cravings for high-fat, high-carb foods.

When you give in to those cravings, your body releases a cascade of rewarding brain chemicals that can set up an addictive relationship with food — you stress, you eat. If you don't consciously control the pattern, you can become physically and psychologically dependent on that release to manage stress. In fact, people who self-medicate with food tend have hair-trigger epinephrine reactions and chronic high levels of cortisol.

You can help yourself keep cortisol in check by limiting caffeine intake to 200 milligrams a day; avoiding simple carbs, processed foods, and refined grains; and getting plenty of high-quality protein. It's also crucial that you find stress-relief techniques that work for you. If you can tame your stress response and lower cortisol levels, you'll have a much easier time losing weight.