Can a hormone imbalance be to blame for weight gain?

November 24, 2020

Can a hormone imbalance be to blame for weight gain?

Hormones are chemical messengers produced by endocrine glands that travel to distant organs and tissues in our body and tell them what to do.

Hormones affect many different processes in the body, from reproduction and menstrual cycle regularity to mood and metabolism. When there’s an imbalance in certain hormones, that can set the stage for weight gain (or difficulty losing weight) and negative health consequences.

We take a look at which hormones may be affecting your weight and some tips for achieving a hormone balance that favors reaching your healthiest weight and optimal health.

In this post, we cover:

  • Some of the hormones that may impact your health and weight, including insulin, cortisol, thyroid hormones, sex hormones, and other hormones
  • The importance of blood sugar balance for hormonal health
  • Why a personalized approach is needed for hormone balance


Insulin is a hormone produced by beta cells in the pancreas in response to elevated blood glucose (sugar). Insulin acts like a “key” that opens the door to your cells to let glucose in where it can be used for energy. As glucose travels into the cells, blood sugar goes down.

Insulin resistance happens when the cells start ignoring the signal that insulin is trying to send. As a result, blood sugar stays high, and your pancreas produces even more insulin. In the meantime, your body’s cells are literally starving for energy and sending strong signals to your brain that you need to eat carbs.

Our bodies generally exist in one of two states: fed (the postprandial state) and fasted. When we have recently eaten, food is being digested, absorbed, and used immediately for energy or stored for later. On the other hand, when it’s been more than 4 hours since a meal, we start to burn stored energy for fuel.

With insulin resistance, your body will act as if it is always in the fed state, never able to tap into that stored energy (fat) for energy.

Therefore, keeping insulin levels low and steady is a crucial part of maintaining a healthy weight. 


Cortisol is a hormone produced by the adrenal glands. While we mainly think of cortisol as a stress hormone, it does have other functions in the body. It regulates how the body converts fats, proteins, and carbohydrates into energy and can also affect your sleep/wake cycle.

Because cortisol is a “fight or flight” hormone, it readies our bodies for those situations: blood sugar goes up, metabolism goes down. High cortisol can also worsen insulin resistance and lead to an increase in appetite. High cortisol has also been linked to an increase in belly fat

Part of the problem is that our bodies make cortisol in response to perceived stress. Your body does not know the difference between the stress you feel when you are in life-threatening danger (such as a lion about to pounce on you) versus the stress you feel when you are, say, running late for work or have an upcoming work deadline.

Furthermore, there’s psychological stress, which we’re all too familiar with, and then there’s physiological stress — such as the stressful state of blood sugar being too low, blood sugar imbalances in general, having too much caffeine, or overexercising or under-sleeping. 


Thyroid hormones are made by the thyroid gland in response to thyroid stimulating hormone produced by the pituitary gland. Thyroid hormones (T4 & T3) are necessary for the proper functioning of every cell in the body. Thyroid hormones influence digestion and metabolism. Our metabolism (and our ability to burn fat) turns up and down in response to more or less thyroid hormone production. 

With hypothyroidism, or low thyroid hormone production, the cause can be either auto-immune (such as with Hashimoto’s thyroiditis, the most common cause of hypothyroid), or it can be non-autoimmune. When our stress hormones (including cortisol) are high, thyroid hormone production decreases

Sex Hormones

There are various reproductive hormones that, in addition to regulating the menstrual cycle and fertility in women (and men!), can also impact weight.

Estrogens, mainly produced by the ovaries but also produced and stored in fat are one such hormone. With estrogens, there’s a sweet spot — too much can cause weight gain, and too little can also cause weight gain. An excess of estrogen promotes fat storage in the body in a female pattern (eg, on the hips and thighs). On the other hand, when estrogen drops at menopause, it promotes weight gain in the form of visceral (or belly) fat

Progesterone, a hormone only produced immediately following ovulation by the corpus luteum in the ovaries, balances the effects of estrogen. Progesterone increases metabolism and body temperature, which burns more calories. Having progesterone that is too low in comparison to estrogen may result in increased insulin, increased belly fat, and a decreased metabolism. 

Androgens such as testosterone (made by the testes in men and primarily in the ovaries in women) and dehydroepiandrosterone, or DHEA (made primarily in the adrenals), promote weight gain because they are in essence, anabolic steroid hormones. They promote muscle mass and bone density but can also promote fat gain in the excess of energy, which is primarily stored as belly fat. 

Other Hormones

Other hormones that can affect weight include leptin, ghrelin, and adiponectin. 

  • Leptin is “the fullness hormone” – produced by fat cells, leptin regulates appetite (when fat goes down, appetite goes up, and vice versa)
  • Ghrelin is “the hunger hormone” – produced by the stomach, ghrelin signals hunger to the brain
  • Adiponectin – produced by fat, improves insulin sensitivity and promotes fat breakdown. Low levels are associated with obesity

Hormone-Balancing Tips

So, what can you do to take care of your hormonal health and achieve a hormone balance that favors optimal health and your healthiest weight? What works for each of our bodies will be different, so a personalized approach is key. As a starting point, here are some tips:

  • Eat a blood-sugar balancing diet to improve insulin sensitivity — this means eating balanced meals that work best for your unique biology, containing adequate protein, fat, and fiber
  • Incorporate resistance training using your body’s largest muscles to improve insulin sensitivity as well as cardiovascular exercise to mobilize fat stores
  • Address high cortisol by getting enough sleep, actively managing stress levels, and avoiding extremes when it comes to diet or exercise
  • Make sure your thyroid hormones and sex hormones are within a normal range
  • Work with a practitioner who specializes in hormones if you need more help!

Let's Recap

  • Several hormones can have an impact on weight. Imbalances in insulin, cortisol, thyroid hormones, sex hormones, and others may be impacting your ability to lose weight
  • Balancing your hormones is crucial to achieving and maintaining a healthy weight
  • By focusing on balancing your blood-sugar with nutrition guidance tailored to your unique biology, lowering your stress levels, hormone imbalances can be overcome!

About the author

This post was written by Melissa Groves Azzaro, RDN, LD, an award-winning integrative registered dietitian and owner of The Hormone Dietitian LLC. She helps busy women with hormone imbalances, PCOS, and fertility issues regain regular periods and get pregnant naturally. She uses a functional medicine, food-first approach that combines holistic lifestyle changes with evidence-based medicine.

She works virtually with clients one-on-one and in group programs, has a self-study course on PCOS called the PCOS Root Cause Roadmap, and is the author of A Balanced Approach to PCOS. Melissa currently serves as Chair-Elect for the Dietitians in Integrative and Functional Medicine Dietetic Practice Group, and has contributed to several online publications, including Healthline.

You can find Melissa at and on Instagram.

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