A Look at Bariatric Surgery … from WebMD Michael Greger M.D. FACLM

Obesity isn’t new, but the obesity epidemic is. We went from a few corpulent queens and kings, like Henry VIII and Louis VI (known as Louis le Gros, or “Louis the Fat”), to a pandemic of obesity, now considered to be perhaps the direst and most poorly contained public health threat of our time. Today, 71 percent of American adults are overweight and 40 percent of men and women appear to have so much body fat that they can be classified as obese, and there’s no end in sight.

In 2013, the American Medical Association voted to classify obesity as a disease against the advice of its own Council on Science and Public Health. Disease implies dysfunction, but bariatric drugs and surgery are not fixing physiological malfunction. Our bodies are just doing what they were designed to do in the face of excess calories. Rather than some sort of disorder, weight gain may largely be a normal response, by normal people, to an abnormal situation. And with more than 70 percent of Americans now overweight, it’s literally normal.

 

What Is Bariatric Surgery?

Bariatric surgeries involve changing our digestive system to facilitate weight loss. As discuss in my video The Mortality Rate of Bariatric Weight Loss Surgery, the use of bariatric surgery has exploded from about 40,000 procedures, noted in the first international survey in 1998, to now hundreds of thousands performed every year in the United States alone. The first technique developed, the intestinal bypass, involved carving out about 19 feet of intestines.

The most common procedure is stomach stapling, also known as sleeve gastrectomy, in which most of the stomach is permanently removed. Only a narrow tube of stomach is left, so as to restrict how much food can be eaten at any one time. Bariatric surgery can be thought of as a form of internal jaw wiring.

Gastric bypass, known as Roux-en-Y gastric bypass, is the second most common bariatric surgery. It combines restriction—stapling the stomach into a pouch smaller than a golf ball—with malabsorption by rearranging our anatomy to bypass the first part of our small intestine. It appears to be more effective than just cutting out most of the stomach. It results in a loss of about 63 percent of excess weight, compared to 53 percent with a gastric sleeve.

After sleeve gastrectomy and Roux-en-Y gastric bypass, the third most common bariatric procedure is a revision to fix a previous bariatric procedure.

 

Is Weight Loss Sustainable After Bariatric Surgery?

As discussed in my video How Sustainable Is the Weight Loss After Bariatric Surgery, bariatric surgery may result in weight loss, but most patients end up regaining some of the fat they lose over the first year or two after surgery, but five years later, three-quarters maintain at least a 20 percent weight loss.

The typical trajectory for someone who starts out obese at 285 pounds, for example, would be to drop to an overweight 178 pounds two years after bariatric surgery, but then regain back up to an obese 207 pounds. This has been chalked up to “grazing” behavior, where compulsive eaters may shift from bingeing, which becomes more difficult post-surgery, to eating smaller amounts constantly throughout the day. Eight years out, about half of gastric bypass patients continue to describe episodes of disordered eating. As one pediatric obesity specialist described, “I have seen many patients who put chocolate bars into a blender with some cream, just to pass technically installed obstacles” [like a gastric band].

 

Does Bariatric Surgery Cure Diabetes?

As I discuss in my video Bariatric Surgery vs. Diet to Reverse Diabetes, after bariatric surgery, about 50 percent of individuals with diabetes and obesity, as well as 75 percent with diabetes and super-obesity, go into remission, meaning they have normal blood sugars on a regular diet off all diabetes medications. Are we sure it was the surgery, though?

At a bariatric surgery clinic at the University of Texas, patients with type 2 diabetes scheduled for a gastric bypass volunteered to first undergo an identical period of caloric restriction, but without the surgery. They were placed in the hospital and put on the same diet they would be on immediately before and after the surgery for ten days, averaging less than 500 calories a day to mimic the surgical situation. Then, the researchers waited a few months so the patients would gain back the weight and then put them through the actual surgery, matched day-for-day to the diets they were on before. So, the same patients and the same diets, just with or without the actual surgery.

If there were some sort of metabolic benefit to the anatomical rearrangement, they would have done better after the actual surgery, but in some ways they actually did worse. The caloric restriction alone resulted in similar improvements in blood sugar, pancreatic function, and insulin sensitivity, but several measures of diabetic control improved significantly more without the surgery. So, the surgery seemed to put them at a metabolic disadvantage.

The caloric restriction works by first mobilizing fat out of the liver. Type 2 diabetes is thought to be caused by fat building up in the liver, which then spills over into the pancreas. Everyone may have a “personal fat threshold” for the safe storage of excess fat. When that limit is exceeded, fat gets deposited in the liver, where it causes insulin resistance. The liver attempts to offload some of the fat, which then gets stuck in the pancreas, and can kill off the cells that produce insulin. By the time diabetes is diagnosed, half of our insulin-producing cells may have been destroyed. Put people on a low-calorie diet, though, and this entire process can be reversed.

A large enough negative caloric balance can cause a profound drop in liver fat sufficient to resurrect liver insulin sensitivity within seven days. Keep it up, and the liver stops spitting out fat enough to help normalize pancreatic fat levels and function within just eight weeks. Once you drop below your personal fat threshold, you should then be able to resume normal intake and still keep your diabetes at bay. The bottom line is that type 2 diabetes is reversible with weight loss, if you catch it early enough.

 

Reasons Not to Have Bariatric Surgery

More than 30,000 intestinal bypass operations were performed before “catastrophic,” “disastrous outcomes” were recognized. This included protein deficiency-induced liver disease, which often progressed to liver failure and death. This inauspicious start is remembered as “one of the dark blots in the history of surgery.”

Today, death rates after bariatric surgery are considered “very low,” occurring on average in perhaps 1 in 300 to 1 in 500 patients. But gastric bypass carries a greater risk of serious complications. Many are surprised to learn that new surgical procedures don’t require premarket testing or, in the United States, for instance, Food and Drug Administration approval, and they are largely exempt from rigorous regulatory scrutiny.

What’s more, up to 25 percent of bariatric patients have to go back into the operating room for problems caused by their first bariatric surgery, as discussed in my video The Complications of Bariatric Weight-Loss Surgery. And re-operations are riskier, carrying around ten times the mortality rate, and offer no guarantee of success. Complications include leaks, fistulas, ulcers, strictures, erosions, obstructions, and severe acid reflux.

Gastric bypass is such a complicated procedure that the learning curve may require 500 cases for a surgeon to master the procedure. Complications risk plateaus after about 500 cases, with the lowest risk found among surgeons who’ve performed more than 600 bypasses. The risk of not making it out alive may be double under the knife of those who’ve done less than 75, compared to more than 450. So, if you do choose to undergo the operation, I’d recommend asking your surgeon how many procedures they’ve done, as well as choosing an accredited bariatric “Center of Excellence,” where surgical mortality appears to be two to three times lower than non-accredited institutions.

Even if the surgical procedure goes perfectly, lifelong nutritional replacement and monitoring are required to avoid vitamin and mineral deficits. This includes more than a little anemia, osteoporosis, or hair loss, but full-blown cases of life-threatening deficiencies, such as beriberi, pellagra, kwashiorkor, and nerve damage, which can manifest as vision loss years or even decades after surgery in the case of copper deficiency. Tragically, in cases of severe deficiency of a B vitamin called thiamine, nearly one in three patients progressed to permanent brain damage before the condition was caught.

The malabsorption of nutrients is on purpose for procedures like gastric bypass. By cutting out segments of the intestines, you can successfully impair the absorption of calories, but at the expense of impairing the absorption of necessary nutrition. Even people who just undergo restrictive procedures like stomach stapling can be at risk for life-threatening nutrient deficiencies because of persistent vomiting. Indeed, vomiting is reported by up to 60 percent of patients after bariatric surgery due to “inappropriate” eating behaviors (in other words, trying to eat normally). The vomiting helps with weight loss similar to the way a drug for alcoholics called Antabuse can be used to make them so violently ill after a drink that they eventually learn their lesson.

“Dumping syndrome” can work the same way. A large percentage of gastric bypass patients can suffer from abdominal pain, diarrhea, nausea, bloating, fatigue, or palpitations after eating calorie-rich foods as they bypass your stomach and dump straight into the intestines. As surgeons describe it, this is a feature, not a bug: “Dumping syndrome is an expected and desired part of the behavior modification caused by gastric bypass surgery; it can deter patients from consuming energy-dense food.”

Colorectal cancer appears to be the only malignancy for which the risk goes up after obesity surgery. After bariatric surgery, the rate of rectal cancer death may triple. The rearrangement of anatomy involved in one of the most common surgeries—gastric bypass—is thought to increase bile acid exposure along the intestinal lining. This causes sustained pro-inflammatory changes even years after the procedure, which are thought to be responsible for the increased cancer risk. In contrast, losing weight by dietary means has the potential to decrease obesity-related cancer risk across the board.

 

Bariatric Surgery and Mental Health

As you can imagine, weight regain after surgery can have devastating psychological effects, as patients may feel they failed their last resort. This may explain why bariatric surgery patients are at a high risk of depression and suicide.

Now, severe obesity alone may increase risk of suicidal depression, but even at the same weight, those going through surgery appear to be at higher risk. At the same BMI, age, and gender, bariatric surgery recipients have nearly four times the odds of suicide compared with counterparts not undergoing the procedure. Most convincingly, before-and-after mirror-image analyses show the risk of serious self-harm increases post-surgery among the same individuals.

About 1 in 50 bariatric surgery patients end up killing themselves or being hospitalized for self-harm or attempted suicide, and this only includes confirmed suicides, excluding masked attempts such as overdoses of “undetermined intention.” Bariatric surgery patients also have an elevated risk of accidental death, though some of this may be due to changes in alcohol metabolism. Give gastric bypass patients two shots of vodka, and because of their altered anatomy, their blood alcohol level shoots up past the legal driving limit within minutes. It’s unclear whether this plays a role in the 25 percent increase in prevalence of alcohol problems noted during the second postoperative year.

Even those who successfully lose their excess weight and keep it off appear to have a hard time coping. Ten years out, although physical health-related quality-of-life improves, general mental health tends to significantly deteriorate, compared to pre-surgical levels even among the biggest losers. Ironically, there’s a common notion that bariatric surgery is for “cheaters” who take the easy way out by choosing the “low-effort” method of weight loss.

Shedding the pounds may not shed the stigma of even prior obesity. Studies suggest that in the eyes of others, knowing someone was fat in the past leads them to always be treated more like a fat person. And there’s a strong anti-surgery bias on top of that, such that those who choose the scalpel to lose weight are rated most negatively (for example, being considered less physically attractive). One can imagine how remaining a target of prejudice even after joining the “in-group” could potentially undercut psychological well-being.

 

Who Is a Good Candidate for Bariatric Surgery?

A body gaining weight when excess calories are available for consumption is behaving as it should. Efforts to curtail such weight gain with drugs or surgery are not efforts to correct an anomaly in human physiology but rather to deconstruct and reconstruct its normal operations at the core. Critics have pointed out this irony of surgically altering healthy organs to make them dysfunctional (“malabsorptive”) on purpose, especially when it comes to operating on children. Bariatric surgery for kids and teens is becoming widespread and performed on children as young as five years old. Surgeons defend the practice by arguing that growing up fat can leave emotional scars and “lifelong social retardation.”

Promoters of preventive medicine argue that bariatric surgery is the proverbial “ambulance at the bottom of the cliff.” In response, a proponent of pediatric bariatric surgery said, “It is often pointed out that we should focus on prevention. Of course, I agree. However, if someone is drowning, I don’t tell them, ‘You should learn how to swim’; no, I rescue them.”

A strong case can be made that the benefits of bariatric surgery far outweigh the risks if the alternative is remaining morbidly obese, which is estimated to shave off up to 13 years of one’s life. Although there are no data from randomized trials yet to back it up, compared to obese individuals who hadn’t been operated on, those getting bariatric surgery would be expected to live significantly longer on average. It’s no wonder surgeons consistently frame the elective surgery as a life-or-death necessity, but the benefits only outweigh the risks if there are no other alternatives.

 

False Advertising

Bariatric surgery advertising is filled with happily-ever-after fairytale narratives of cherry-picked outcomes offering, as one ad analysis put it, “the full Cinderella-romance happy ending.” This may contribute to the finding that patients often overestimate the amount of weight they’ll lose with the procedure and underestimate the difficulty of the recovery process. Surgery forces profound changes in eating habits, requiring slow, thoroughly chewed, small bites. Your stomach goes from the volume of two softballs down to the size of half a tennis ball in stomach stapling, and half a ping-pong ball in the case of gastric bypass or banding.

Even if surgery proves sustainably effective,” wrote the founding director of Yale University’s Prevention Research Center, “the need to rely on the rearrangement of our natural gastrointestinal anatomy as an alternative to better use of feet and forks”—that is, exercise and diet—“seems a societal travesty.”

Might there be a way to lose weight healthfully without resorting to the operating table? Yes, a whole food, plant-based diet.

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