Hormones and weight gain

Hormones and weight gain

Hormones and weight gain

Can your hormones play a factor in weight loss? Continue reading to find out.

The Found Team
Last updated:
August 19, 2021
5 min read
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Have you ever felt that no matter what you try, you can’t seem to achieve your weight-loss goals even when you’ve already joined a weight loss program? Does it feel like there’s some invisible factor keeping you from reaching your desired weight? You might have even experienced an unexplained weight gain.

Perhaps the problem isn’t with your habits. What if it’s all because of what’s going on behind the scenes at a hormonal level?

Hormonal causes of weight gain happen when an imbalance in one or more of your body’s hormones causes you to gain weight—and it’s a real issue. Thankfully, there are ways to fight hormonal weight gain and even lose weight. The first step in controlling hormone-related weight fluctuations is understanding the issue. Read on for all the details.

Understanding hormones

We’ve all heard about hormones at one point or another, whether in a science class or from a doctor or friend. But what exactly are hormones? And what do they do? This is fundamental information for understanding how hormone health and weight loss are connected, so let’s dive in.

The term “hormone” refers to a class of chemicals that are made naturally by the body. These groups of molecules can be thought of as your body’s postal system: they travel through the bloodstream, giving your body the necessary information to carry out processes such as: 

  • Metabolism
  • Mood regulation
  • Reproduction

Hormones are created in your endocrine glands, which can be found in places like the pancreas, thyroid, and ovaries (among others). And while your hormones are microscopic, they play a significant role in regulating your body’s basic functions—including weight gain and weight loss.

Too much or too little of any one hormone can cause a hormonal imbalance and skew the way your body works.

How hormones affect weight loss

Countless factors influence weight, including but not limited to:

  • Diet
  • Sleep
  • Exercise
  • Stress

Even though we may feel we have full control over these aspects of our lives, each can be affected by our hormones.

For example, you could come up with the perfect meal plan and stick to it for months. On paper, the diet should be helping you shed pounds with ease. But if the hormones that influence your metabolism are out of balance, you may not see any results—no matter how many kale smoothies you gulp down.

In turn, our diet, sleep, exercise, and self-care habits can affect our hormone level.

If a lack of sleep causes a hormonal imbalance that slows your metabolic rate, what’s the real problem and how are sleep and weight loss related? On the surface, the cause of the problem is sleep deprivation. But, when you look behind the curtain, the root of the issue is a change in hormone levels.

In short, hormones and weight gain are connected because, well, everything in the body is connected.

That’s why maintaining the right hormone balance is crucial, not only to weight loss but also to general health.

The hormones that affect weight and weight loss

As you might expect, different hormones fulfill different functions within the body. Let’s take an in-depth look at some of the hormones the body produces and how each of them impacts body weight.


Leptin is a hormone released by the body’s fat cells. It was identified in 1994, and researchers have since determined that it plays a role in regulating energy usage and long-term food intake. Translation: leptin works to maintain body weight.

  • Leptin is sometimes called the “satiety hormone” due to the way it signals to your body that you’re full.
  • It inhibits hunger, telling your brain that you don’t need any more energy.

If you have excess fat cells, they should create enough leptin to tell your body to stop eating. This means that, in theory, when you have more than the “optimal” level of fat cells, your body will produce more leptin, causing you to feel satisfied, eat less, and return to the “optimal” amount of fat for your body.

The problem is that overproduction of the hormone can lead to something called leptin resistance.

When your sensitivity to leptin decreases, your body doesn’t “listen” to that hormonal call to stop your food intake. Eating more may mean the production of more fat cells, which can then lead to even higher leptin levels. As such, maintaining a healthy amount of leptin-producing fat cells can help you lose weight.


If leptin tells us when to stop eating, ghrelin tells us when we need to start. Often dubbed the “hunger hormone,” ghrelin is mostly produced in the gastrointestinal tract and signals to the body that it needs food. It also tells the body to conserve energy when stores are low.

In short, ghrelin is a hormone that regulates your appetite.

Ghrelin levels fluctuate naturally throughout the day, increasing when we get hungry and dropping after meals. They may even be tied to the body’s circadian rhythm.

Because ghrelin affects appetite and hunger levels, a decrease in ghrelin would theoretically lead to less of a desire to eat, making weight loss easier. With that said, studies suggest that ghrelin also plays a role in other processes such as insulin regulation and sexual behavior. As such, decreasing ghrelin is not the holy grail of weight loss, though it can be beneficial.


Many are likely familiar with insulin as a treatment for managing diabetes. But did you know that insulin is a hormone that the pancreas naturally produces?

  • After the food you eat is converted into blood sugar, your pancreas releases insulin.
  • Insulin ensures that the blood sugar enters your liver and cells so it can be used for energy.
  • When everything is functioning properly, low insulin levels—which can occur when you haven’t eaten for a few hours—will trigger your liver to release the blood sugar it stored away.

But if too much blood sugar continually enters the bloodstream, the pancreas produces more than enough insulin, and the body can develop insulin resistance. This causes a blood sugar level spike, which can pave the way for type 2 diabetes. 

What’s more, once the liver is full of blood sugar, the excess is directed to fat cells where it’s stored as fat.


You may have heard stress and weight gain are correlated. The reason for this is in part due to the hormone cortisol. Cortisol is produced naturally in the adrenal glands and is released regularly throughout the day at reasonable levels. However, when stress levels increase, cortisol levels do too.

As one of the body’s “stress hormones,” cortisol affects weight in a few ways. Most importantly, when you’re stressed out, cortisol tells your body to conserve energy in preparation for the upcoming stressful situation. In other words, your metabolism slows, meaning you burn fewer calories. As such, it can be harder to lose weight when stressed. 

Learn how to restart your metabolism to get back on track with your weight loss goals.


Testosterone (often shorted to T) is a sex hormone produced naturally by men (in larger quantities) and women (in smaller quantities). It affects many aspects of the human body: sex drive, bone growth, the appearance of body hair, and more.

And—you guessed it—testosterone plays a role in body weight.

Interestingly, both too high and too low testosterone levels can cause hormonal weight gain.

  • Because testosterone is involved in the building of muscle mass, a lack of it can mean fewer muscle cells. And since muscles burn energy quicker than fat, the ultimate result of low testosterone levels can be a reduced metabolism.
  • On the flip side, too much testosterone can lead to weight gain—most likely due to an increase in appetite.
  • As there are other issues related to imbalanced testosterone levels, maintaining proper T levels is a must.


Produced by women and, to a lesser extent, men, estrogen is also one of the sex hormones found in our body. Like testosterone, estrogen has several main functions, including building bones and regulating mood.

There are several forms of estrogen, and one of them—estradiol—helps in the regulation of your metabolism. When the estrogen level declines (especially when menopause occurs), the ensuing decrease in metabolic rate can lead to hormonal weight gain or menopause weight gain.

Optimizing hormones for weight loss

While hormones play a crucial role in regulating and maintaining weight, there is no single weight loss hormone. Nor is there a one-size-fits-all hormonal treatment (or a one-size weight loss program in general, for that matter). And nobody knows that better than our team at Found.

About Found

Found is among the largest medically-supported weight care clinics in the country, serving more than 200,000 members to date. To start your journey with Found, take our quiz.

Published date:
August 19, 2021
Meet the author
The Found Team
The Found Team


  • Medline Plus. Hormones. https://medlineplus.gov/hormones.html
  • NCBI. Leptin and the regulation of body weight. https://pubmed.ncbi.nlm.nih.gov/21460597/
  • CDC. Insulin Resistance and Diabetes. https://www.cdc.gov/diabetes/basics/insulin-resistance.html
  • Medical News Today. What to know about ghrelin. https://www.medicalnewstoday.com/articles/ghrelin#other-effects
  • Harvard Health Publishing. Testosterone — What It Does And Doesn't Do. https://www.health.harvard.edu/drugs-and-medications/testosterone--what-it-does-and-doesnt-do
  • Medical News Today. Can estrogen levels affect weight gain? https://www.medicalnewstoday.com/articles/321837#menopause-estrogen-and-weight
  • NCBI. Beneficial effect of hormone replacement therapy on weight loss in obese menopausal women. https://pubmed.ncbi.nlm.nih.gov/10515671/
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