Presented by John Morton, MD, MPH, FACS, FASMBS
Chief, Bariatric and Minimally Invasive Surgery
April 13, 2017
An obesity crisis still grips America, leaving 1 in 3 people obese. Rates of adult obesity have doubled in the last 20 years. When doctors go looking for the cause, they see multiple villains.
One of the most treacherous of all may be our own body’s grip on calories, said John Morton, MD.
That’s because our ancestors often lived in places where food was scarce and unpredictable. Their bodies adapted by holding onto extra weight gained in good times to get them through the lean times. That survival strategy can work against people in modern society.
“Back in the old days…we weren’t sure where our next meal was coming from,” said Dr. Morton in a recent lecture at the Stanford Health Library. Putting on a few extra pounds was insurance against starvation. “Nowadays, when we have food everywhere, it’s not so important that we maintain those calories.”
The body’s own efficiency in stockpiling calories is just one of the factors that has led to a rapid rise in obesity in the last 20 years, said Dr. Morton, who is chief of bariatric and minimally invasive surgery at Stanford University School of Medicine.
“What’s changed is how we live, how we work, how we play,” he said. Many people have less time to cook healthy meals with fresh fruit and vegetables. It’s harder to find time to exercise or to sleep. “All of those things are leading to us gaining weight,” Dr. Morton said.
Not getting enough sleep can trigger a body response that spurs people to eat. That’s because, when someone is tired, their body “looks” for energy in a lot of different ways—including food, Dr. Morton said.
Fatigue can cause the body to release a “hunger hormone” called ghrelin that pushes people to eat. “Your body knows it’s stressed out, and it’s trying to get energy through calories,” Dr. Morton said.
His person experience reflects that finding. Years ago, when he was training to learn surgery, he sometimes had to be on call for long hours at night to take care of medical emergencies. “For some reason, I always wanted pancakes the next morning,” he said.
Because of the body’s powerful push to get calories and keep them stored in the form of weight, losing extra weight is a huge challenge for most people, Dr. Morton said.
But carrying extra weight raises the risk for a lot of other serious medical problems, Dr. Morton said. So we need to find ways to help people lose weight.
Among the medical risks that rise with obesity are:
- Death from cancer. Death rates from all kinds of cancer are 52 percent higher in men and 42 percent in women who are morbidly obese
- Medical complications from all kinds of treatment, including hip and knee replacement surgery. Also, a hip or knee implant that’s meant to last 30 years may last only 10 years in someone obese
- Less ability to get pregnant
Dieting has been the first solution that many people turn to, with encouragement from their doctors. Yet very few people–less than 10 percent in one study–are still on a diet a year after they start, Dr. Morton said.
Combining dieting with exercise should help, yet studies have found that people lose an average of 6 pounds after a year. “Not a lot,” Dr. Morton said.
One study that followed the participants in “The Biggest Loser” TV reality show found that all but one of them regained the weight they had lost. These participants were highly motivated, yet even they showed how hard it is to prevent regaining weight.
All of this has led medical researchers to acknowledge that the barriers to losing excess weight are high.
“This is something more than a willpower issue,” Dr. Morton said. “It’s not motivation. It’s not psychology. It’s physiology.”
Studies have found that when people try to lose extra weight, the body reacts by increasing the release of ghrelin, the hunger hormone. “The body’s not stupid,” Dr. Morton said. “It’s going to do everything in its power to regain that weight and then some.”
That situation has led doctors to recognize that some people need help beyond dieting, Dr. Morton said. It’s time to pay attention when someone’s BMI hits 30 or higher. BMI, or body mass index, is a measure of height and weight. A BMI of 30 corresponds to a weight of 186 pounds for a 5-foot-6 person.
At that point, “It’s time to start talking to your physician about what’s available,” Dr. Morton said. “That’s when we really start to see the mortality rates go up.”
There are now several choices for weight loss beyond dieting, including newer drugs, devices, and surgery.
Some older drugs proved not to be very effective or had high risks. At most, people lost 4-6 pounds a year on those drugs, Dr. Morton said. Some newer drugs are more effective and can be used in combination with other weight-loss procedures.
One new option for weight loss is a device: a balloon that’s inserted into the stomach. Called the “intragastric balloon,” this device has been available in the United States within the last 2 years, Dr. Morton said.
The balloon is inserted through the mouth and moved into the stomach, without making any incisions. It is intended for people with a BMI of 30 to 40 (obese, but not morbidly obese).
An FDA study found that people on average lost one-third of their excess weight, and 80 percent were able to keep off the lost weight more than one year.
“We’ve had good results” with the balloon device, Dr. Morton said. At Stanford, patients on average have lost about 40 pounds in 6 months.
The balloon device is intended to be a temporary option. It is removed in 6 months to make sure the balloon material doesn’t degrade. “It’s not meant to replace surgery or compete with it,” Dr. Morton said. “It’s temporary.”
Weight-loss surgery is the next step in treating obesity. Usually people quality for this surgery if their BMI is 40 or more, or if their BMI is 35 and they have related medical problems like diabetes.
Weight loss surgery includes:
- The newest surgery, called sleeve gastrectomy, which removes part of the stomach. At Stanford, people lose about 60 percent of their excess weight with this surgery, according to data Dr. Morton showed.
Sleeve gastrectomy reduces the stomach from the size and shape of a football to a long skinny tube like a banana. With a smaller size stomach, people feel full sooner after eating
Sleeve gastrectomy has become the most popular operation in the United States, Dr. Morton said.
- Stomach banding surgery, once popular, and now fallen in favor. At Stanford, people lose about 41 percent of their excess weight with this surgery.
“It’s like putting a belt across the stomach,” Dr. Morton said. “You can tighten it up or loosen as needed.”
Studies found about half the patients are able to keep their weight off over time. While the operation is generally safe, there is a risk that the band can slip off or lead to an infection.
- Gastric bypass surgery. People lose an average of 75 percent of their excess with this operation.
This is an older more extensive surgery that disconnects most of the stomach, leaving a very skinny tube instead to connect the digestive tract. At Stanford, all bariatric surgery is done with small incisions (called laparoscopy), so people can leave the hospital within 1 to 2 days.
Dr. Morton called this the “metabolic operation” because people not only lose weight, they also tend to get rid of (or reduce) diabetes and high blood pressure. Some people who were taking insulin for diabetes before the surgery are able to stop it as soon as a week after surgery.
Gastric surgery is usually reserved for people with a BMI of 50 or more, or if they have severe diabetes or bad stomach acid reflux. It does have a small risk of complications, including a hernia, a leak or insufficient absorption of vitamins. Patients are followed closely and treated for any of these issues.
Gastric bypass surgery can help people lose most of their excess weight. People with a BMI of 50 before surgery often achieve a BMI of 30 at the end of a year, Dr. Morton said.
No matter how good the surgery is, long-term success in weight loss depends on people sticking to new healthier eating habits.
Surgery can give people an initial boost in learning new habits, because the hunger hormone ghrelin plummets after surgery.
“That’s not forever,” Dr. Morton said. It last about 6 months, long enough for people to learn new eating patterns.
“You can see that really helps introduce new habits,” Dr. Morton said. “That way, people maintain lower volume for their diet. They eat more protein and less carbs,” he said.
“This way, they don’t have their body working against them, they have their body working for them.”
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