Hormone Changes after Weight Loss Surgery

Managing Hormone Changes After Weight Loss Surgery

August 6, 2018

Rerouting your intestinal tract is going to change some of your hormones—including reducing your hunger. Bariatric surgery, such as gastric sleeve and gastric bypass, reconfigure the anatomy of your gastrointestinal tract (stomach) which recalibrates your energy balance and fat metabolism.

The most pronounced change is the reduction of the intestinal hormone called ghrelin, also called ‘the hunger hormone.’ As a result, hunger and appetite are diminished, increasing prolonged feelings of fullness (satiety). As a result, you feel less interest or desire to eat.

Interestingly, this and how other surgically-induced hormone changes function is in sharp contrast to those changes produced by traditional weight loss.

How Hormone Changes After Weight Loss Surgery Versus Dieting

Hormone changes after weight loss surgery promote rapid weight loss by maintaining or enhancing energy expenditure (calories burned). In fact, some surgeries even increase energy expenditure relative to changes in body size. Significant weight loss is also associated with additional changes in your body that help to reduce defects in fat metabolism.

With increased weight loss, you will find yourself inspired to engage in more physical activity, which increases your body’s ability to burn more fat and increase your energy levels to do more. Exercise is also a stress reducer and mood elevator, helping to combat emotional eating.

Significant weight loss also reduces the insulin hormone (used to regulate sugar levels) and cortisol (stress hormone). This can put people diagnosed with type 2 diabetes and pre-diabetics into remission, often permanently, when weight loss is sustained.

Improved Sex Drive and Function After Bariatric Surgery

An important quality of life component that is often overlooked in obesity and bariatric medicine is sexual health. People with obesity frequently report decreased sexual desire and overall satisfaction.

The Journal of the American Medicine Association (JAMA) performed a clinical trial with women who had undergone surgical weight loss and reported they experienced significant improvements in overall sexual functioning, in most reproductive hormones of interest, and in overall psychosocial status.

Weight loss can stabilize your hormones. Studies have shown as little as a 10 percent weight reduction can be effective in improving ovulation and menses. Doing so can help reduce the level of androgens in your body and reduce negative symptoms and boost fertility.

Polycystic Ovary Syndrome (PCOS)

PCOS is a hormonal disorder common among women of reproductive age. They may have infrequent or prolonged menstrual periods or excess male hormone (androgen) levels. The ovaries may develop numerous small collections of fluid (follicles) and fail to release eggs regularly.

Women with PCOS produce too much insulin, or the insulin they produce doesn’t work the way it should. The inability of insulin to function normally is one reason why women with PCOS tend to gain weight or have a hard time losing weight.

The exact cause of PCOS is unknown, but obesity is often a common side effect and factorial contributor to the condition.

In turn, very overweight women (BMI of 30 or higher) have a higher risk of PCOS, which can cause:

  • Decrease or failure to ovulate
  • Irregular menstrual cycles
  • Painful periods
  • Polycystic ovaries
  • Acne
  • Excessive body hair growth

In my medical practice, I have treated several women battling PCOS. After bariatric surgery, many have lost 50 percent of their excess weight and eventually gone on to carry successful pregnancies. (This is true job satisfaction!)

Endocrine-Related Risks After Bariatric Surgery

Hormone-related complications can occur with any type of bariatric surgery. While the overall risk factor of complications is low, issues that may arise are due to the way food is rerouted through the intestine or how the stomach empties.

Endocrine-Related Risks

  • Macronutrient deficiency—a lack of protein and calories caused by reduced absorption, in severe cases, can cause swelling, diarrhea, dehydration, and heart problems
  • Micronutrient deficiency—a lack of vitamins and minerals which are essential for many functions in the body
  • Bone loss—bone loss can lead to weak bones (osteoporosis)
  • Low blood sugar—glucose levels after eating, which is also called hypoglycemia

One of the critical reasons to keep your post-op follow-up appointments with your surgeon and your bariatric team is to stay up-to-speed on all aspects of your health during and after the weight loss cycle.

I ask my patients to jot notes about any questions they have or unusual health issues they may be experiencing. Most are common and temporary post-operative bumps in the road that will pass. However, it is always important that you feel comfortable picking up the phone to check in with your doctor’s office to ask questions and express any concerns you have.

The hormonal changes that happen after weight loss surgery are often significant. But the substantial weight loss that the operation offers helps to normalize hormones and offset severe fluctuations during the normal course of aging.



Dr. Seun Sowemimo is a board-certified laparoscopic, bariatric and general surgeon, specializing in the treatment of metabolic syndrome (obesity). He is the medical director at Prime Surgicare and co-medical director of Central Jersey Bariatrics, located in Freehold, NJ.

Read more articles by Dr. Seun Sowemimo!