Hormones and Weight Gain: Cortisol, Leptin, and Ghrelin

Finally, as we draw to the end of March and the “Trigger States” theme, we’re going to take a look at the science behind the connection between hormones and weight gain, and how hormones are influenced by your lifestyle.

So far, we’ve covered sleep hygiene, stress management, and mindfulness strategies.

But today, the question we want to scientifically answer is: “Why does stress management matter so much for health?”

The answer involves both hormones and behavior, as well as the delicate balance between biological and hormonal processes, which we cannot directly control, but can indirectly influence.

Control vs. Influence

This is a topic that I have covered probably dozens of times. Past blog posts come to mind:

In my work with clients, I always find it important to distinguish what people can directly control from what they can indirectly influence.

Things we cannot control: 

  • Our genetics
  • Our current weight
  • Disease or chronic conditions
  • How long we live
  • Other people’s actions

The mistake that people often make, however, is that once they realize they cannot control something, they completely give up. In the process, they miss out on how powerful influence can be.

Things we can influence through our behaviors (contrasted to the list above): 

  • The expression of our genes
  • Our future weight and long-term health projections
  • The management of disease and chronic conditions
  • Our quality of life
  • How we respond to others

Influence is potent. 

In fact, when we utilize the power of influence, we empower ourselves to enjoy something very close to actual control. In my work with clients, this is often because when people take responsibility for what they can control, they realize that they actually control a whole lot more than they initially thought.

It’s simple, yet life-changing.

Now, let’s circle back around to hormones and stress. It is essential that you understand the difference between control and influence, because you cannot control your hormones. However, you can use strategies, behaviors, and habits to influence the hormonal balance in your body to a significant degree.

Let’s explore how and why stress and lack of sleep often drive hormonal changes in cortisol, leptin, and ghrelin, which causes weight gain.


Now let’s add one more dimension to the conversation of control vs. influence. Often, our health circumstances are not only dictated by a combination of our genetics and behavior (nature and nurture), but our bodies also tend to create feedback loops. Once something starts happening, it’s easy to get caught in the cycle.

Cortisol is a great example of this feedback loop. Cortisol is the “stress hormone” that is secreted by the adrenal gland.

You may read mainstream magazines that pinpoint cortisol as the cause of belly fat, specifically. However, a little dig into the research reveals that it’s not that simple. It’s more of a feedback loop than a direct cause-and-effect.

When you become chronically (and uncontrollably) stressed, your body secretes more cortisol, which can change your cravings – many people become more attracted to high-sugar and high-fat foods when cortisol is released. Comfort food is a coping mechanism for stress, but it becomes maladaptive when it affects weight and health.

Then, problematically, once you accumulate abdominal fat over a period of time, the mere presence of this belly fat causes more cortisol to be released when you are under stress. See how it becomes a cycle?

More cortisol, more belly fat. More belly fat, more cortisol. And on and on it goes.

The scary thing is that one study showed that women with more belly fat actually behaved differently under the influence of stress than women who had a leaner mid-section. The over-secretion of cortisol created a sense of helplessness, in which the women with a higher waist-hip-ratio seemed to “fold” in response to stress. The women with a lower waist-hip-ratio, however, had a lower secretion of cortisol and actually demonstrated angrier reactions to the stressors.

In other words, the women who over-secreted cortisol internalized the stress, while the women whose adrenal systems did not flood with cortisol externalized the stress.

This is why stress management is important, and why taking responsibility for change is so powerful.  There is a dramatic connection between stress, cortisol, and weight, which cannot be reduced to an oversimplified headline like, “Stress causes belly fat.” It’s so much more complex than that, and is a bi-directional flow between hormones, feelings, behavior, and results.

If we can abandon our feelings of helplessness and directly address the chronic stressors in our lives, we have a shot at ending the cycle of cortisol secretion and belly fat accrual. 

Leptin and Ghrelin

Leptin is a hormone that is secreted by fat cells, and it is the “fullness hormone.” Leptin helps to regulate eating, by signaling to the brain and body that you are full.

Ghrelin is the “hunger hormone,” and it is produced in the gastrointestinal tract, and it works in tandem with leptin to help you manage your energy and get enough food.

The interaction between leptin and ghrelin is meant to help you maintain weight. You can also use smart eating and exercise strategies to work with these hormones for an intelligent weight loss plan. It’s a delicate dance, which – again – you cannot directly control. However, you can heavily influence the balance of these hormones and your body’s sensitivity to them through your actions and lifestyle.

Sleep greatly affects the production of leptin and ghrelin. In one study, participants who restricted their sleep to less than 8 hours per night experienced suppressed leptin and increased ghrelin. In other words, they were hungrier, and harder to satisfy.

This is why I often tell clients to just go to sleep. It is very difficult (and often unnecessary) to manage high levels of stress by working through the night. As I have written before, not only are you likely to do a poor job on your work, but your body starts working overtime, producing elevated cortisol and ghrelin, while depressing the levels of leptin. Throwing exercise into the mix often does not help, and sometimes hurts.

This is the essence of the “Trigger State” – stressed, tired, and hungry. When you feel this way, you truly have almost no willpower left, and my experience with many clients is that exercise cannot put a dent in the dysfunctional eating that is driven by cortisol, leptin, and ghrelin.

Hormones and Hunger

To boil it down, elevated levels of cortisol and ghrelin caused by stress and shortened sleep lead to poorer food choices, which often leads to weight gain. Then, the weight gain itself, especially if it is in the midsection (which it often is when it is cortisol-related), can automatically cause cortisol to over-produce when you’re under stress. When you’re under stress, you often lose perspective and over-work in all the wrong ways, often putting yourself under more stress, and missing more sleep.

And on and on it goes.

Once the vicious cycle takes hold, it’s hard to break. 

However, remember that there are things that you can control, and they can break the cycle. Like:

  • Using good sleep hygiene strategies
  • Implementing healthy and appropriate work-life balance
  • Practicing mindfulness techniques
  • Becoming aware of how stress impacts eating, and finding ways to self-soothe (that aren’t food) during stressful periods
  • Improving your coping skills for difficult times
  • Being pro-active about food preparation and portion control strategies to short-circuit mindless/emotional overeating during periods of stress

It takes time, but improving your relationship with stress and building up your strategies for lifestyle management yields huge gains over time. This is why I urge people to get out of a simple “diet mentality.” Building a big-picture healthy lifestyle is not just about the body – it also includes mind and spirit.

How’s this for a conundrum? Even though we can’t control the hormones that drive behavior, we can take responsibility for the lifestyle factors that control our hormones.

And when we do, everything has the potential to change.

Strategy of the Week

You only have one strategy for this week. It is to reflect for a moment on which situations make you feel the most stressed. Which situations make you feel helpless? Which situations feel totally out of your control? Your job is to identify these situations that happen in your life, and make a three-step plan for how you will confront these “trigger states.”

Step 1: Identify the characteristics of this situation, and how you will know it is happening 

Step 2: What can you do ahead of time to prevent this situation from happening, if possible? 

Step 3: What coping skills and self-soothing strategies can you implement during this stressful period to prevent mindless/emotional overeating? 

Follow-Up Questions from Last Week

If you want to jump into this free healthy living project, all you have to do is start today by shooting me an e-mail to let me know you’re “in!” Each week, I e-mail strategies to my mailing list on Monday. If you would like to be on this list, please scroll down and sign up!

Last week in “Mindfulness: Meet the Inner Narrator,” we talked about how improving your relationship with your “inner narrator” (the tape that constantly runs inside your head) can revolutionize your mental approach to health and fitness. There were a few strategies for you to try. Let me know how this has been going by answering the questions below:

  • What strategies did you use to cultivate a “stillness practice?”
  • What did you notice about your “media diet” this week? Did you notice any changes?
  • What did you notice about your automatic thoughts? Did you practice challenging or questioning these beliefs?

E-mail these answers to me! 

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Rachel Trotta

I am a Certified Personal Trainer, Fitness Nutrition Specialist, Physique and Bodybuilding Specialist, and Women's Fitness Specialist. I live in New Jersey in the NYC metro area, and I coach clients online all over the world. As a trainer and health writer, my mission is to make healthy living sustainable for the average person. I’m also a wife, mom, nature lover, runner, avid cook, weightlifting aficionado, history nerd, travel addict, and obsessive podcast listener. Get in touch!

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