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Bariatric Surgery & Hormones: How They Affect Each Other

Bariatric Surgery & Hormones: How they Affect Each Other

Achieving and maintaining weight loss can feel incredibly difficult, and hormones may be one reason why many people have a hard time losing weight and keeping it off. Hormones are the chemical messengers that carry signals throughout your body to complete a wide range of tasks. Some hormones are involved in digestion, appetite, and other body processes related to weight, and imbalances in these chemicals can have an adverse effect on your health.

Bariatric surgery is a medical option for those who have not been able to lose weight with other methods. In addition to weight loss, it may have an impact on your hormones and on health conditions caused by hormone imbalances.

What Is Bariatric Surgery?

Bariatric surgery is a weight loss surgery that treats obesity by limiting the amount of food that can fit in the stomach. Most people who receive the operation have a body mass index of over 40, which is categorized as extremely obese. After bariatric surgery, you feel full after a small amount of food, which helps you reduce your caloric intake and lose weight.

This procedure has a number of benefits for people who struggle with obesity. It helps to reduce the risk of weight-related health conditions like heart disease, liver disease, and type 2 diabetes. Not only does it lead to weight loss, but it also can help patients develop balanced eating habits that sustain long-term weight management.

Types of Bariatric Surgery

There are several types of bariatric surgery that alter the stomach in different ways. The most common is Roux-en-Y gastric bypass, or RYGB. During this procedure, the surgeon cuts the top of the stomach to form a small pouch. Then, this pouch is redirected to the small intestine, so the food bypasses most of the stomach.

Another form of bariatric surgery is adjustable gastric band, or AGB, which involves placing a band near the top of the stomach, creating a small pouch for food. With this method, the surgeon can later tighten or loosen up the band to let more or less food into the stomach.

Some patients get a sleeve gastrectomy, which removes the majority of the stomach, leaving a sleeve that cannot hold much food. This differs from bypass because it permanently removes a large portion of the stomach instead of displacing it.

How Hormones Affect Weight Loss

Hormones are instrumental in a wide variety of your body's processes, including functions related to your weight. One hormone closely linked to weight management is leptin, which regulates your appetite. Typically, your body releases leptin as you gain fat, which reduces your appetite and keeps you from overeating. Then, as you lose fat, your leptin levels drop, causing you to feel hungrier.

Ghrelin is another important hormone involved in weight loss or gain. Your body secretes ghrelin when you've gone a long time without eating, which reminds you that it's time for a meal. It plays a role in digestion, too.

In men, testosterone may affect body fat percentage. It's normal for testosterone levels to decline slightly in your 20s or 30s, but a significant imbalance could lead to weight gain or difficulty losing weight.

Effects of Bariatric Surgery on Hormones

The main purpose of bariatric surgery is to reduce food intake for weight loss. However, the surgery and its weight loss results can also have an effect on levels of various hormones throughout your body. This could further benefit your health and your ability to sustain your weight loss in the long run.

For example, the appetite-stimulating hormone ghrelin is produced in the stomach. Because the gastric sleeve surgery removes so much of the stomach, it can reduce your body's ghrelin levels and therefore reduce your appetite.

Weight loss following bariatric surgery can reduce or reverse several major health conditions that are caused in part by hormonal imbalances. Losing weight is one of the best treatments for type 2 diabetes because it lowers insulin levels. An imbalance of insulin, a hormone secreted by the pancreas, is the primary cause of the condition.

Bariatric surgery can help treat PCOS, or polycystic ovary syndrome, as well. This is a hormonal disorder that may be caused by an imbalance of insulin. Since weight loss reduces insulin, it's an effective way to manage PCOS and reduce symptoms.


There are risks associated with any medical procedure. In some cases, bariatric surgery causes negative health effects. If you're considering the surgery, you and your doctor will discuss the risks and benefits to decide whether it's the right option.

Patients may be at an increased risk of nutritional deficiencies after bariatric surgery because their food intake is limited. These deficiencies can affect a wide variety of body processes, including the release of hormones. Another issue that can develop after the surgery is low blood sugar, or hypoglycemia.

Hormones play a key role in regulating your body's other systems. When certain hormones are out of balance, you may struggle to control your appetite or have the energy to exercise. Bariatric surgery can help you overcome these challenges, and the resulting weight loss may lead your hormone levels to return to normal.

Take a look at our Bariatric Surgery Resources and most asked questions here.