Bariatric Surgery FAQ

Hormone Changes After Bariatric Surgery

Hormone Changes After Bariatric Surgery - Bariatric Fusion

Bariatric surgery can affect your body in many ways, including your gut and sexual hormone levels.

In fact, many of the weight loss side effects that result from this type of surgery can be attributed to changes in hormone levels.

This is why weight loss surgery has become a popular treatment for obesity due to hormonal changes that can be impactful and long-lasting.

In fact, many patients have reported improved sexual functioning. In some cases, this is attributed to changes in the endocrine system.

This article will discuss some of the most common hormonal changes that occur as a result of bariatric surgery. We also look at some of the side effects of these changes and how to properly manage them.

What This Article Covers:

Hormone Changes After Bariatric Surgery

Research suggests that hormonal changes may take place for a variety of reasons, and in a variety of ways.

This is probably because there are many types of bariatric surgery, each presenting with its own set of benefits, side effects, and hormonal changes.

First, let’s look at the primary causes of hormonal changes that occur as a result of bariatric surgery.

Why Do Hormonal Changes Occur After Bariatric Surgery?

Bariatric surgery is the collective name for the procedures that help individuals dealing with severe obesity lose weight. This is accomplished by restricting food intake, limiting the absorption of nutrients, or a combination of both.

Due to this, many endocrine-related organs are affected. Many associated hormones may also be affected.

Why Do Hormonal Changes Occur After Bariatric Surgery?

The most common hormones that are discussed in relation to bariatric surgery are Ghrelin (“the hunger hormone”), GLP-1 (glucagon-like peptide which is released in response to food), and leptin (a hormone produced by your bodies’ fat cells”).

These changes are mostly related to diet and lifestyle changes. Alterations to the intestinal tract can affect endocrine functioning and hormonal composition.

However, it should be noted that a lot of research has also studied the effects of bariatric surgery on sexual hormones, such as testosterone and estrogen amongst others.

Bariatric surgery has helped many people achieve their weight-loss goals but like any surgery, it is not without risk. There are also varying risks depending on the type of bariatric surgery you want to have.

In most cases, three main types of bariatric surgeries are identified. This would include Adjustable Gastric Band Surgery, Roux-En-Y Gastric Bypass Surgery, and Gastric Sleeve Surgery.

Gastric Band Surgery involves the placement of a band around the top portion of the stomach that can be adjusted to allow a small amount of food into the stomach at a time.

Roux-En-Y Gastric Bypass Surgery reduces the stomach size, which is associated with restrictive calorie intake. The alterations to the intestinal tract in this surgery also promote malabsorption of nutrients for the outcome of weight loss.

Gastric Sleeve Surgery reduces stomach size and slows the digestive process.

Between these surgery types, Roux-En-Y and Gastric Sleeve Surgery procedures are more often studied in terms of the hormonal changes.

This is why it is wise to look at the positive and negative hormonal changes that may occur as a result of the surgery. First, we talk about the positive hormonal changes.

Positive Outcomes Due To Hormonal Changes After Bariatric Surgery

Treatment of Type 2 Diabetes

Bariatric surgery has been associated with positive changes in diabetic health due to improved glucose homeostasis in the body.

Glucose homeostasis merely refers to a balance between insulin and glucagon that can maintain glucose levels in the body. Roux-En-Y Gastric Bypass surgery is often the type of surgery chosen for obese individuals struggling with type 2 diabetes. Gastric bypass has been shown to improve diabetes within days, even before rapid weight loss begins.

Treatment of Type 2 Diabetes

Interestingly, the treatment of diabetes and glucose homeostasis has been primarily associated with hormonal changes and not alterations to diet and a reduction of fat.

Specifically, an increase has been seen in the GLP-1 hormone and Peptide YY. Peptide YY, which is the hormone responsible for telling the body you are full.

Peptide YY is often studied in terms of obesity and other eating disorders. Bariatric surgery has shown to contribute to an enhanced Peptide YY response to food intake. In turn, increasing satiety after a small amount of food.

Bariatric surgery has also been associated with insulin increases. As a result, diabetics may notice improved glucose levels after surgery.

In fact, this effect has become so pronounced that about 80% of people who are diabetic before surgery, experience improved symptoms after.

Improved Fertility Rates

Obesity in women has been linked to low reproductive health and other reproductive issues.

There is a growing body of research suggesting that hormonal changes after bariatric surgery have been associated with a higher possibility of getting pregnant when compared to obese women.

In obese women, a hormone profile is usually characterized by altered secretion of the hormone gonadotropin. This may lead to irregular menstrual cycles and a further reduction in metabolite excretions that are important for fertility.

It is said that this can account for the link between obesity and infertility.

After bariatric surgery, this hormone profile is reversed and increases. Several other hormones have shown improved fertility rates.

However, it is recommended that patients wait at least a year and a half after surgery before trying to conceive.

Many physicians will advise a strict diet plan for pregnancy and monitor nutrient intake in order to maintain health for the fetus and mom.

It should be noted that there may still be a risk of complications.

Increased Testosterone Levels

Obesity in men has been associated with low testosterone levels. Following bariatric surgery, these levels have been shown to return to normal about 12 months after bariatric surgery.

This improves cardiovascular and sexual health and may also reduce the risks associated with lower testosterone levels.

For example, low testosterone levels have been related to muscle loss that accelerates the effects of aging. This is known as sarcopenia.

A study conducted at Stanford Hospital found that of the men who had bariatric surgery, 63% had low testosterone levels prior to surgery and this number dropped to 41% after surgery.

It is interesting to note that 80% of people who undergo bariatric surgery are women. Men often prefer testosterone replacement therapy.

However, it is highly recommended that men undergo gastric bypass and related surgeries as a means for stabilizing their testosterone levels. Not only can this improve their health, but also their overall quality of life.

Improved Sexual Health

It has been mentioned that hormonal changes in estrogen and testosterone may occur after bariatric surgery, but how does this affect patients’ sexual health?

In obese men, increased estrogen and decreased testosterone levels have been associated with poor sexual function.

Bariatric surgery may increase testosterone levels in men, and increase fertility and sexual health.

However, the same research has not been proven equally beneficial for women.

It has been found that while women may experience improvements in fertility and reproductive health, they may only enjoy a slight increase in their sexual health.

Lower Blood Pressure

Hypertension is the clinical term for abnormally high blood pressure. The condition is generally caused by diet or other chronic ailments.

Lower Blood Pressure

Some of the symptoms include headaches, nosebleeds, chest pain, and shortness of breath.

It has been found that gastric bypass surgery may positively reduce the risk of hypertension and lower high blood pressure.

This has mostly been related to changes in the gastrointestinal tract and the neurons that respond to GLP 1 and leptin levels.

The effects of bariatric surgery on hypertension have been documented as the most effective treatment against hypertension.

Some studies also prove its efficacy, especially when it is measured against other medical interventions.

Lower Cholesterol Levels

Most people are unaware that cholesterol exists in good and bad forms in the body. The good type of cholesterol is transported by high-density lipoproteins and low-density lipoproteins refer to bad cholesterol.

It is also a known fact that high-fat food, smoking, and lack of exercise may contribute to a prevalence of bad cholesterol in the body, or what is commonly known as “high cholesterol”.

Due to the hormonal changes associated with bariatric surgery, which increasingly regulate hunger and the feeling of fullness, cholesterol may be positively reduced in the body.

In addition, a change in diet and introduction of exercise can further contribute to reduced cholesterol in the body.

Risks Associated With Hormonal Changes After Bariatric Surgery

In some cases, hormonal changes have been found to lead to gastric bypass long-term side effects.

These are not very common, but have been identified as risks patients should be aware of before they undergo surgery.

Some of these risks can also be mitigated by choosing the right type of surgery for you. This is because each type of surgery presents its own risks and hormonal changes.

There are also some preventative measures that can lower the risks presented below.


A lot of research has been conducted on the link between bariatric surgery and depression.

Naturally, one would think that the weight loss effects post-surgery contribute to positive mental health changes.

Unfortunately, a restrictive diet can lead to negative changes in mental health in many cases.

Interestingly, some research suggests that the diet can directly affect changes in serotonin levels in the body, which in turn, alters neurotransmitter activity that can cause depression and anxious moods.

Serotonin is the hormone that ensures stability in mood and also general feelings of well-being and happiness.

Women have lower overall levels of serotonin, therefore they may be more prone to depression than men.

Other factors and lifestyle changes post-surgery may contribute to feelings of despondency, including the fact that activities that were previously enjoyed may now be off-limits (e.g., dining out with friends, drinking alcohol).

The best way to curb the effects of depression is to ensure that you follow your diet, get a moderate amount of exercise once it is allowed, and maintain adequate sleep.

Nutrient Deficiency

This is a common side-effect and can largely be attributed to several hormonal changes that are closely linked to drastic diet alterations and restrictive calorie intake.

This can take the form of a lack of macronutrients (protein or calories) and/or micronutrients (vitamins and minerals).

Any type of bariatric surgery could result in nutritional deficiency, especially if a patient does not closely follow their doctor’s prescriptions, diet plan, or fail to take bariatric vitamins.

bariatric multivitamins

These vitamins are absolutely essential and it is often recommended to use a bariatric multivitamin with iron in order to boost nutrient levels and iron levels simultaneously.

This is especially important when considering that iron deficiency is one of the most common side effects of gastric bypass and one of the most common contributors to hair loss after gastric bypass surgery.

Another important aspect of curbing nutrient deficiencies has to do with ensuring that you get enough protein after surgery.

When dietary protein intake is limited, bariatric meal replacements/protein shakes are a great addition to the diet in order to ensure adequate daily protein intake.

Nutrient deficiencies are preventable when staying consistent with supplement intake post-surgery.

Weakened Bones

The development of osteoporosis has been studied as the end result of bone loss and reduced bone density after bariatric surgery.

Symptoms include bad posture, back pain, and bones that are prone to break or crumble.

It is thought that hormonal changes are one of many other factors that may result in this condition.

It has also been studied as one of the Roux-En-Y gastric bypass side effects.

However, it should be noted that loss of bone density has closely been associated with Vitamin D deficiency in patients, as well as calcium insufficiency.

On the hormonal spectrum, this condition is associated with changes in the gonadal, leptin, gut hormones, and adiponectin (a type of adipokine that is commonly associated, and invertedly related to, fat mass).

Of these, most research has been done on the effects of leptin and gut hormones.

Post-Bariatric Hypoglycemia

Hypoglycemia after bariatric surgery is also referred to as late dumping syndrome.

Researchers believe it to be caused by GLP-1 and gastric-inhibitory polypeptide that is linked to the ability of hormones to affect and stimulate insulin release and secretion.

This condition refers to a large spike in glucose levels after eating, which leads to the high secretion of insulin and consequently lowers blood sugar.

Symptoms include increased heart rate, light-headedness, abdominal pain, and fatigue. Luckily, there are many ways to treat these conditions.

This includes portion control, especially regarding carbohydrates. This would include eating low GI carbs, as opposed to eating high GI and highly refined carbs.

In addition, doctors recommend that patients must include healthy fats in their meals and make sure there is adequate protein intake.

In more severe cases, medicinal treatments such as calcium-channel blockers, octreotide and diazoxide, have proven helpful.

Some patients also respond to acarbose, but in cases where none of this helps, surgical treatment must be considered.

Peripheral Neuropathy

Peripheral neuropathy refers to nerve damage that may present as pain or numbness in the feet, hands, or legs. The numbness can take the form of sharp and throbbing pain or have a gradual onset.

Many patients are also sensitive to touch. It has been associated with a reduction of gut hormones, especially GLP 1, although research on the topic has been sparse.

Peripheral neuropathy can also develop from deficiency of vitamins like thiamin after bariatric surgery.

In this regard, it is important to just take note that this is part of the gastric bypass risks associated with the procedure.

It has been found that this procedure may affect about 10% of patients, but the literature suggests that the condition may also go undiagnosed. As with any risk, it is best to keep an eye on your symptoms post-surgery.

Final Comments

There are a lot of benefits that come from bariatric surgery. However, the risks should always be taken into consideration.

It is important to know that every surgery comes with its own risk and that at the end of the day, it is about weighing the pros vs cons. Bariatric surgery has been associated with long-term and sustainable weight loss.

This surgery has given many people the freedom to do things they never could before and improved physical and mental health.

It can be difficult to abide by all the post-surgery restrictions. However, following a healthy diet, consuming adequate protein, and taking supplements for life have all been associated with a great reduction risk factors associated with bariatric surgery.

Remember, there are also many positive effects of this surgery such as improved diabetes, cholesterol, and lowered blood pressure.

All in all, if you have been struggling with your weight and it has affected your quality of life, this surgery comes highly recommended.

Do your research and consult with your healthcare provider to ensure you choose the type of surgery that is best suited to your unique needs.

Hormone Changes After Bariatric Surgery (FAQ)

Can you regain the weight that is lost after bariatric surgery?

Yes, in fact about a third of people regain the weight they lost during surgery.

Even though hormonal changes can lead to positive health changes, your diet and lifestyle must be permanently changed in order to make this a sustainable weight loss option.

Which bariatric surgery is best?

One surgery is not better over another. It is all about your specific needs. Roux-En-Y, Gastric Sleeve Surgery, and Gastric Band have all been associated with positive effects and weight loss reduction.

However, Gastric Band is considered less risky because it does not cause hormonal changes and carries slightly less risk.

Who qualifies for bariatric surgery?

You may qualify for surgery if your BMI is over 40. You can also qualify if your BMI is between 35 and 40 and you have fatty liver disease, high cholesterol, sleep apnea, and hypertension.

People with a BMI between 30 and 35 may qualify if they have uncontrolled diabetes.

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**This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your physician or another qualified health provider with any questions in regards to a medical condition.

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