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Cortisol and Weight Loss

Here’s Why So Many Diets Fail

Cortisol and Weight Loss

Here’s Why So Many Diets Fail

It’s like that Greek myth about the man cursed to roll a boulder up a steep hill for eternity. Every time he neared the top, the boulder would roll back down. And he’d have to start all over again.

That’s what dieting can be like for many people. It’s a frustrating cycle. First, you find a new diet. And the results are great. You’re hitting weight-loss goals, watching the numbers on the scale tick down. But suddenly, no matter the diet, you hit a plateau. The numbers aren’t budging anymore. In fact, at a certain point, they may inexplicably start climbing again.

It seems like an insurmountable hurdle. How can you take control of your weight if you don’t understand what’s impacting it? But here’s the thing: There’s a little-discussed factor that may be behind your struggles. And it’s called cortisol.

You may have heard of cortisol, the body’s main stress hormone. As an essential part of your body’s flight-or-fight-or-freeze response, cortisol levels surge in your bloodstream during periods of stress. It’s meant to give you the energy you need to handle risky situations. But did you know that if your cortisol levels are too high, your body could struggle to shed pounds? It doesn’t matter how much progress you think you’re making … high cortisol can keep knocking you back to square one.

In this case, think of cortisol as the hill you need to climb, the seemingly insurmountable hurdle making it impossible to shed or maintain your desired weight. However, by understanding your cortisol levels, you can flatten that hill and take back control of your health.

How High Cortisol Sabotages Your Diet

Here’s an eye-opening statistic: Millions of people around the globe are in a battle with their diets right now. In fact, in the U.S. alone, about 45 million people go on a diet every year. Yet about 80% of those who lose a large amount of body fat can’t sustain that over the next year. And over the next two years? Well, in one study, dieters on average will have regained more than half of what they lost.

The reason, for many, comes down to stress. As we mentioned, when you’re stressed, your body releases the cortisol hormone to help boost your energy. That’s because the hormone helps regulate the metabolism of fats, carbohydrates and even proteins. It also manages your glucose (blood sugar) levels. All things that can be used for fast energy.

But when you’re under constant stress (be it physically or mentally), your body goes into high alert … and it stays there. It’s attempting to keep you focused, ready to react to whatever the threat may be. And when left in “on” mode too long, your fight-or-flight-or-freeze response can play havoc with your body. The resulting high cortisol levels may mean:

Burning Fewer Calories:

Cortisol is thought to impact your metabolism in a few ways. For one, cortisol is a catabolic hormone, meaning it breaks down your molecules for energy use. That’s why cortisol can break down proteins (aka your muscles). So, with too much cortisol, your body will find it harder to build muscle. Meanwhile, your body also produces less testosterone when flooded with cortisol, which also leads to a decrease in muscle mass. When you lose muscle mass, your resting metabolism slows, and you burn less calories.

In 2014, researchers from Ohio State University interviewed a number of women about the stressors they encountered the previous day. Then, they fed them a high-fat, high-calorie meal. When done, the researchers evaluated the women's metabolic rates and cortisol levels. On average, the women who reported one or more stressors during the past day burned 104 fewer calories than the more relaxed women. If this trend continued, it would mean a gain of about 11 pounds in a year.

Stress Eating:

We’ve all heard of stress eating. Well, it’s not just a baseless phrase. In times of stress, we crave high-fat, high-sugar, and salty foods for comfort. And there’s a reason for this. Those types of foods increase our blood sugar, give us energy and calm our cortisol levels.

In fact, in 2007, researchers found that stressed people with high cortisol levels were more likely to snack in response to daily hassles in their regular lives than low-cortisol responders.

Storing Fat:

Now, what happens when your blood sugar levels remain high? After all, cortisol is ramping up blood sugar levels in every way it can to provide you with the energy it thinks you need. Well, here’s where we introduce insulin into the story. Insulin moves sugar from your blood into your cells, where it can be used for energy. Known as a storage hormone — it also stores energy as either fat or glycogen (the name of stored glucose).

However, when cortisol is at high levels for too long, you could start developing a resistance to insulin. That’s when your cells fail to react to insulin properly. And that means more insulin and high blood sugar. So what happens? Well, that unused fuel has to be stored now. And although your cells are resistant to insulin’s effect on blood sugar uptake, they may remain open to its role in fat storing.

As a result, your fat storage increases, specifically in the abdomen. That’s because the fat cells in your belly are particularly sensitive to high insulin. They’re also far more effective at storing energy than the fat cells in, say, your lower body.

Clearly, chronic stress and high cortisol can play havoc on your health. In fact, you could say having high cortisol is as if you’re overeating all the time. So if you’re experiencing chronic stress, that might be the reason it’s so difficult to find a successful diet and push that “boulder” up the hill.

To finally make some progress, you need to understand how much stress you’re under. And you need tried-and-true methods of reducing it.

Beat Stress and Take Control Back

If you’ve been struggling with diet after diet, or you’re simply starting on the journey to a healthier you, you need to find ways to control your stress and your cortisol levels.

At, we’ve compiled a list of proven stress-reduction techniques here. There are a number of options you can take to lower your cortisol (including some anti-inflammatory diets). All of this will go a long way to helping you diet effectively and stay healthy.

Before you go, we have one more question for you: How can we get better? Here at, our goal is to gather the best information to help you understand the science of stress. If you think we missed anything in our research, please let us know. You can reach us here.

Related Research:

This article has been Medically Reviewed by Ioana A. Bina, M.D., Ph.D.

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Cortisol and Weight Loss

It’s like that Greek myth about the man cursed to roll a boulder up a steep hill for eternity. Every time he neared the top, the boulder would roll back down. And he’d have to start all over again.

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We all know how it feels to be stressed. Stress, after all, is part of our everyday lives. It’s that feeling we get whenever we face a new demand and our body goes into high alert. It’s why we often think of stressed people as tense or on edge.

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When you think about stress, what comes to mind? Looming work deadlines, financial worries, feeling overwhelmed? In today’s world, stress can take on countless forms. Sometimes, it’s even a force of good. But a key reason behind it all is often overlooked. In this article we’ll explain everything: the good, the bad, the ugly, and why controlling your stress can be a matter of life or death.

Jessica Cohn-Kleinberg

Written by

Jessica Cohn-Kleinberg

Written on:

November 24, 2021 at 11:04:50 AM


February 1, 2022 at 10:16:32 AM

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