Weight gain occurs for multiple reasons. Those of us emerging from the holidays a few (or many) lbs heavier than when we started know a few brownies and glasses of eggnog that could be the culprits. But, holiday snacking and drinking is not the only reason for weight gain. In fact, many of the reasons we gain weight have nothing to do with how much we exercise or how much we eat. Instead, factors like inflammation, leaky gut, changes in your microbiome, environmental toxins, and your genes are directly contributing to your weight gain. One huge and very often-overlooked reality is that a hormonal imbalance causes weight gain.

Which Hormones Contribute to Weight Gain?

Insulin takes the cake when it comes to hormones in your body that contribute to weight gain. Insulin actually contributes to much more serious issues like Inflammation and chronic disease. However, this hormone is not the only disruptor in the body when it comes to weight gain. Thyroid, cortisol, and your sex hormones all play a role in your weight and health. A hormonal imbalance causes weight gain when these hormones are too prevalent or too minimal in your body.  Let’s look at each one briefly below.


Low-thyroid function, or hypothyroidism, is extremely common yet often undiagnosed. With low thyroid function, your body does not produce enough of thyroid hormone, which causes symptoms such as:

  • Constipation
  • Inability to tolerate cold
  • Depression
  • And, of course, weight gain

Many things interfere with proper thyroid function, such as environmental toxins, nutrient deficiencies (including zinc, selenium, iodine, and omega 3 fats), gluten intolerance, and stress. Thyroid function plays a huge role in healthy weight and yet it is still misdiagnosed and mistreated very regularly.

Three Tips for Low Thyroid Function:

1.     Get the correct thyroid tests! Ask your doctor to check your thyroid stimulating hormone [TSH and free T3 and T4, as well as thyroid peroxidase (TPO) and anti-thyroglobulin antibodies]. Dr. Rosselli at RevitalIV tests for all of this and more!

2.     Eat for your thyroid: raw cruciferous vegetables like kale should be limited. The word to focus on here is “raw.” Cooking cruciferous vegetables like this are much better for thyroid health than raw. Foods high in zinc and selenium, such as oysters and pumpkin seeds, are also very good for your thyroid health.

3.     Replace and OPTIMIZE your Thyroid Hormones: Most people do best on bioidentical hormones or a combination of T4 and T3. A doctor who understands how to optimize thyroid balance can customize a nutrient protocol for you.


Stress stimulates hormone responses in the body that cause weight gain and insulin resistance. Cortisol is a hormone produced in the adrenal gland that helps your body with its fight or flight instinct. This means that when your body is threatened in some way, Cortisol gives you a surge of energy that allows you to run faster, hear better, and even see further. It also shuts down your metabolism. This is fine in the short term, but after long periods of stress, weight gain, high blood sugar, high blood pressure, and muscle loss is common.

Too much cortisol is also damaging to other hormones in your body. Pregnenolone is a hormone that produces cortisol. It also produces your sex hormones, which we will dicsuss next. However, if your Pregnenolone is producing too much cortisol because of stress, it doesn’t have the time to produce the following important sex hormones.

Did you know a Sex Hormone Imbalance Causes Weight Gain?

Estrogen and testosterone imbalances can also lead to weight gain and muscle loss. Excess estrogen, for instance, can not only cause a woman to gain weight but keep her from losing it. In men, excess estrogen can cause a beer belly, loss of body hair, muscle loss, and even the dreaded “man boob.”

Low Testosterone can also cause men to gain weight and lose muscle—in addition to causing sexual dysfunction, low sex drive, fatigue, brain fog, and even bone loss.

Hormone imbalances are even associated with increased risks for obesity. A recent study examined the interaction between the decrease in estrogen secretion and the prevalence of obesity in menopausal women. It notes: “The [sex]  hormones help integrate metabolic interaction among major organs that are essential for metabolically intensive activities like reproduction and metabolic function. Sex steroids are required to regulate adipocyte metabolism and also influence the sex-specific remodeling of particular adipose depots. In humans, the factors that control fat distribution are partially determined by sex hormones concentrations.” In layman’s terms: your sex hormones are integral to both weight gain and fat distribution on your body. 

Bioidentical Hormone Therapy

Bioidentical hormone therapy uses hormones that are biologically identical to the hormones that your body makes on its own. Unlike synthetic hormone products, bioidentical hormones are easily assimilated into the body because the body recognizes them as their own. This reduces potential risks or side effects that may occur with synthetic options.

When your hormones are properly balanced, your body has an easier time metabolizing your food, gaining muscle, and losing weight. In addition to the physical symptoms a balanced hormonal system provides, your mental health is also greatly improved with hormone balance. Your mood stabilizes, you have more energy, and you begin to feel more like yourself. This alone is what keeps some people indoors eating instead of being active outdoors enjoying our beautiful Florida weather.

Tips for Sex Hormone Imbalances and Weight Gain:

1.     Get the CORRECT Hormone Tests! Not all hormone tests are created equal. A standard blood test does not measure even a fraction of the hormones that are active in your body. A physician that provides bioindentical hormone treatments will test you with the latest and most accurate hormone tests.

2.     Check your GUT. For men and women, keeping your gut healthy cultivates a healthy sex-hormone metabolism. It also helps your bioidentical hormone therapy to balance your hormones more quickly. Sugar, refined carbs, and alcohol spikes estrogen in the body. Too little fiber or too many toxins in your body can affect your body’s ability to properly detoxify the excess estrogen in your body. Keeping your gut healthy is extremely important.

3.     Visit a Bioidentical Hormone specialist who understands that complexities of the hormonal system do not occur in a vacuum. Proper micronutrients, gut health, diet, and exercise are all key components to keeping your hormones balanced and keeping you at a healthy weight.

Check your hormones today to see if an imbalance is keeping you from losing the weight! 561-406-2202

Dr. Matteo Rosselli, D.O.

Medical Director and Co-Founder of Revitalogy

With over two decades of experience as an anesthesiologist, Dr. Rosselli has witnessed the extraordinary benefits of intravenous hydration treatments firsthand.  His specially-formulated treatments for conditions such as migraines, hangovers, and jet-lag, as well as his highly-innovative customized treatments for pre-/post-operative procedures have been so beneficial for his own patients that he was inspired to open RevitalIV and offer these treatments to the public. Dr. Rosselli’s priority is to provide the safest and most effective strategies for optimal health, slowing the aging process, and restoring the youthful vitality that decreases as we age. He believes that the integration of revolutionary medical research with his patients’ individual health profiles is the most optimal method for prescribing anti-aging medicine programs that will produce effective results.

His revolutionary syntheses of BioIdentical Hormone Therapy, IV hydration, and Physician-Formulated Vitamin Supplementation, have been drastically reducing age-related disease and symptoms while restoring a youthful and beautiful energy to his patients.