Freakonomics in the Times Magazine: The Stomach-Surgery Conundrum

For their Nov. 18, 2007, “Freakonomics” column, Dubner and Levitt revisit a favorite topic: unconventional weight loss. In September 2005, they wrote about Seth Roberts, who shed 40 pounds with a diet he crafted through years of meticulous self-experimentation. This week’s column digs into the risks and benefits of using surgery to combat obesity. This blog post contains additional research materials.

1. There are two main types of bariatric surgery: gastric bypass, and laparoscopic adjustable gastric banding (Lap-Banding), which is less invasive than a full bypass. This paper, from the journal Archives of Surgery, describes Lap-Banding, and reports it to be both effective and safe.
2. Bariatric surgery is often the most effective treatment for the morbidly obese, and with a mortality rate of around one percent, it isn’t terribly risky, according to this paper by Bennet Omalu et.al. (abstract only without subscription). The highest risk is faced by patients who undergo the procedure at the hands of an inexperienced surgeon. This Washington State study, by David R. Flum and E. Patchen Dellinger, shows a strong correlation between survival rates and surgeon experience (abstract only without subscription).
3. Bariatric surgery can be costly, ranging from $15,000 to more than $30,000, depending on the procedure. But the surgery tends to pay for itself, according to several studies, including this one from the journal Medical Clinics of North America (abstract only without subscription).
4. The column features Dr. Marc Bessler, a prolific bariatric surgeon and an innovator in the field. More information about Dr. Bessler is available here.
5. One of the risks of bariatric surgery, for people who are addicted to eating, is what psychologists call “addiction transfer.” According to this Wall Street Journal article, a significant fraction of bariatric patients pick up other addictive habits afterward, like gambling or smoking, or fall into alcoholism.
6. But that risk is far outweighed by the benefits of the surgery, which include significant health cost savings over the long term, according to this article in Surgery News.
7. In the column, Dubner and Levitt discuss commitment devices, which are strategies people use to lock themselves into a particular course of action. Levitt defined it more fully last year in the Freakonomics blog.
8. Short of surgery, one commitment device might be to leave an anatomically correct blob of fake human fat in your kitchen. To see what a disgusting pet fat glob looks like, click here. Fake fat usually comes by the pound, but, for the calorie-conscious executive, MyPetFat.com sells an office-ready 1-ounce version.
9. Annual gym memberships are another purchase on the commitment device shopping list for those trying to lose weight. Except that people overestimate by 70 percent how much they will use them, as Dubner and Levitt wrote in their Jan. 7, 2007 column, “The Gift Card Economy.” The column references Stefano DellaVigna and Ulrike Malmendier‘s paper Paying Not to Go to the Gym.
10. The popular new weight-loss pill Alli, which partially blocks the body’s absorption of fat, is a commitment device with real consequences: a person who takes Alli and then eats too much may experience a bout of oily diarrhea. (Among the initiated, this is known as an Alli-oops.)
11. But commitment devices don’t get much more real than the one used by the legendary Chinese general Han Xin. Before battle, Xin was known to arrange his troops with their backs to a river, so they knew retreat wasn’t an option. More on his story here.