Can Stress Make You Fat?

By Denis Faye

Stress and poor eating go hand in hand. A hectic lifestyle can leave you with little free time and plenty of exhaustion. For thousands of overworked, under-relaxed Americans, grabbing a quick burger at McGreasy's and skipping yoga class doesn't seem like a choice. It feels like a survival necessity.

It's all about hormones . . .

But in truth, the problem goes beyond how a few (hundred) extra calories can impact your gut. Your bodily functions are regulated by chemicals called hormones—and hormones are regulated by a series of glands throughout your body known as your endocrine system. These glands don't work independently. Much like a government, a soufflé recipe, or a John Irving novel, they're all interconnected and if one part is impacted, it can cause a cascade of health issues, including weight gain.

For example, for most of us, stress prevents you from sleeping well. This is a problem because this stimulates production of a hormone called ghrelin, which tells you to eat and decreases the levels of the hormone leptin, which tells you to stop eating. In other words, when you don't get your 7 to 8 hours of sleep, your hormones send signals to your brain to eat more.

Why are those bad ol' hormones beating you while you're down? Probably because, in primitive times, we didn't sacrifice sleep so that we could sit at a desk for an extra 4 hours or watch an entire season of The Walking Dead in one sitting. Instead, when we didn't sleep, it meant we were on a 24-hour buffalo hunt or our cave had been flooded in the middle of the night so we were seeking shelter. In these situations, we needed to eat more because we needed energy for these demanding tasks.

. . . especially cortisol.

But that's just a small example of how stress can make you fat. The much larger issue has to do with your stress hormones, particularly everyone's favorite biological bugbear, cortisol.

When thrown into a "fight or flight" situation, your endocrine system adapts by jacking your brain with adrenaline (aka epinephrine) in an effort to marshal all your bodily functions into solving the problem at hand. Blood flow to your brain increases to sharpen your wits. Blood is also sent to your extremities so that you can fight your way out of the situation or run away. (Contrary to the title, humans can't actually "fly" in stressful situation, although that would be cool.) To pump all this blood around, your heart beats harder and you breathe harder so that you're getting plenty of oxygen.

But if you remained in this state too long, you'd probably have a heart attack, so the next thing your body does is release noradrenaline into your system to normalize things and flush the excess hormones from your system (this is why people sweat in stressful situations). Then, if the issue isn't completely resolved, the body releases a separate hormone to cope with prolonged stress: cortisol.

When it's doing what it's supposed to do, cortisol is great. It keeps you ready for action. It raises your blood pressure, elevates blood sugar, and diverts energy from other tasks to whatever is mission critical (healing, for example).

But it tears up your body in order to do this. To keep blood pressure up, it retains sodium in your cells. (Oh, hey there, water weight!) To keep blood sugar up, it breaks down lean body mass (muscle). And when it diverts energy, less immediately critical systems, such as digestion, are impaired. What's more, this whole process depletes micronutrients like crazy.

Chronic stress can make you fat in a number of ways. Faulty digestion means you don't absorb nutrients as well, which can also influence your ability to exercise. (I know claiming that cortisol inhibits your ability to exercise sounds contradictory considering its raison d'être is to make you battle ready, but remember that cortisol was never intended for months or years of use—or abuse.)

Want a more direct link? A study in the journal Psychoneuroendocrinology showed that cortisol increased women's desire to eat foods high in sugar and fat. So if you're stressedand you don't sleep, it means that your poor willpower is being hit from all sides by ghrelin and cortisol.1

Even if you can resist those late night fridge raids, you're still at risk. A study in the journalPsychosomatic Medicine showed that excess cortisol directly contributed to visceral adipose tissue around your stomach and intestines (aka "belly fat") because the enzyme 11 beta-hydroxysteroid dehydrogenase that is used to convert inactive cortisol to active cortisol is found in higher concentrations in visceral fat. Visceral fat is associated with increased risk of diabetes and cardiovascular disease. So, cortisol might not make you fatter, but it can give you a beer belly—and potentially, a heart attack.2

What you can do about cortisol

There are supplements out there that claim they can combat cortisol, but they don't work. There are also adaptogens and antioxidants, which are great for fighting some stress-related issues, but they haven't been proven to lower cortisol levels.

But there are a few simple things you can do to reduce cortisol levels:

1. Get Regular Exercise. A sweaty, hard bout of cardio creates a "positive" stress situation that puts that extra cortisol to good use.
2. Meditate. Giving your brain a break reduces anxiety—and that reduces cortisol. I recommend starting with the audiobook Meditation for Beginners by Jack Kornfield.
3. Laugh. Having a good time cuts though stress like a hot knife through coconut oil. Maybe it's time to upgrade yourThree Stooges collection to Blu-ray—just make sure to watch it with some friends. Social interaction helps too.

See a pattern here? The best way to combat stress—not to mention the weight and other health-related issues that come with it—is to do things that help you stop stressing. So do your hormones, your mind, and your waistline a favor. Try to relax a little.

Sources:

1. Epel, E., R. Lapidus, B. McEwen, et al. Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behavior. Psychoneuroendocrinology 26: 37-49, 2001.
2. Epel, E.S., B. McEwen, T. Seeman, et al. Stress and body shape: stress-induced cortisol secretion is consistently greater among women with central fat. Psychosomatic Medicine 62:623-632, 2000.