Do women respond differently than men to bariatric surgery? Do they face different risks? Do they enjoy different benefits? The short answer is that both men and women tend to lose substantial amounts of weight with weight-loss surgery (WLS). The risk of serious complications appears to be similar in both groups. However, there are a few differences between men and women when it comes to bariatric surgery.

Who Gets WLS More Often and Why?

Approximately one-third of men and women in the United States are currently considered obese. But about 85 percent of weight-loss surgery patients are women. There may be several reasons for why women are more likely to seek out WLS. Men can lose weight faster and easier with diet and exercise alone because they have more lean muscle mass and a higher metabolism. They may respond well to non-surgical interventions. Women, on the other hand, may feel greater social pressure to change their appearance by losing weight. They may also be more likely to feel the need to take good care of their health. Women tend to visit the doctor for regular health checkups much more often than men and may be more aware of their options for weight loss. Finally, the percentage of women who are extremely obese with a BMI of 40 or more is higher than men (4 percent vs. 2.9 percent according to a 2010 Gallup study). These patients are most likely to qualify for WLS.

Who Benefits Most From WLS?

As far as weight loss is concerned, women who have gastric bypass tend to lose about 10 percent more of their excess weight compared to men, according to a study by the Einstein Healthcare Network. However, the reduction in comorbidities such as type 2 diabetes, sleep apnea and hypertension is similar for all patient groups. One surprising finding from a Swedish study that followed patients for more than 10 years found that women who had WLS reduced their overall cancer risk by 42 percent compared to obese women who did not have bariatric surgery. Men did not appear to enjoy the same benefit, but the sample size was too small to be sure. Women also tend to have a reduction in vascular inflammation (an effect not seen in men after WLS). Another happy result of substantial weight loss is an improvement in fertility (especially for women with polycystic ovarian syndrome) and a lower risk of pregnancy-related complications, such as gestational diabetes and hypertension.

Bariatric Surgery Risks for Women

WLS carries a small risk of a serious complication called pulmonary embolism – a condition that occurs when a blood clot in the leg travels up into the lungs. Women are advised to stop taking their hormonal birth control pills for several weeks leading up to surgery to ensure this risk stays low.

There is some evidence that men are at higher risk than women for death within the first 30 days after WLS. However, the greatest risk appears to be from having the procedure done by an inexperienced surgeon.

Nutritional Deficiency after WLS

Gastric bypass in particular is associated with an inability to absorb critical vitamins and minerals. Women who have not yet entered menopause are at high risk for developing anemia due to iron loss during menstruation. Women are also at high risk for severe osteoporosis from calcium deficiency. Folic acid deficiency during pregnancy can negatively affect a woman’s unborn child (as can the inability to eat sufficient quantities of food). Regular vitamin and mineral supplementation and careful adherence to post WLS diet are required to eliminate these risks. Fortunately, most women can carry a baby to term with no increase in the risk of birth defects or low birth weight as long as their nutrition is adequately monitored and supplemented as needed throughout their pregnancy.

Embarrassing Side Effects of WLS for Women

Some awkward side effects of bariatric surgery appear to be more common or more troubling for women than for men. For example, 55 percent of women vs. only 31 percent of men report a worsening of urinary or fecal incontinence after their surgery. This side effect may be treatable depending on the underlying cause. For many WLS patients, sticking to the strict post-surgery diet helps limit episodes of diarrhea.

Sudden, extreme weight loss and decreased nutrition are strongly associated with hair loss. In fact, about 40 percent of WLS patients report thinning hair after surgery. This problem usually starts at about the three-month mark. Women may find this problem more distressing than men. Fortunately, the condition corrects itself over time. Within a year to a year and a half, most patients have a full head of hair again. Maintaining good nutritional intake helps reduce hair loss.

Loose skin and sagging body contours are the other big changes that can make women feel upset after bariatric surgery. As breasts get smaller, they lose their shape and droop even more than they did when they were larger. The nipples may point down toward the floor. Skin all over the body including the arms, abdomen, buttocks and thighs can sag. Women may feel more self-conscious about their appearance after WLS than men. After weight has stabilized, plastic surgery can usually re-contour the body and make it look smoother again.