The Shangri-la diet is not a diet in the usual sense of a set of meal plans or detailed instructions about calorie intake and nutrition. The book that was published in 2006, The Shangri-la Diet, is perhaps better described as a discussion of a psychological theory about human appetite than a diet book, strictly speaking. The core of the author's theory is that people gain weight because they have been conditioned to have a strong association between food and flavor, which keeps the appetite demanding more of a specific source of calories in order to continue tasting the flavor. If a person can break the association between flavor and food intake, they can lose weight because they will not feel hungry as often or as intensely. The book suggests several ways in which this association can be broken, thus leading to lifelong reduction in calorie intake with relatively little physical or emotional distress. As one newspaper reporter describes the diet, “… it seems that you may eat whatever you wish under the [author's] plan, but you just won't want to.” The diet has generated considerable controversy since its publication, not only in regard to its theory of appetite and weight control, but also about the role of expert review and clinical trials in evaluating new diets.
The name of the Shangri-la diet comes from a novel titled Lost Horizon, written in 1933 by James Hilton about a mythical paradise called Shangri-la, hidden from the world somewhere in the Himalayas and guided by the wisdom of a Tibetan lama. The word Shangri-la entered English common speech as a synonym for a utopia or Garden of Eden when Frank Capra directed a movie based on Hilton's novel in 1937. Seth Roberts, the author of The Shangri-la Diet, maintains that he chose the name of his diet because of its association with an earthly paradise. He told an interviewer in 2005, “[I picked the name] because it puts people at peace with food—like being in Shangri-la, a peaceful place. It reduces or eliminates food compulsions, such as eating between meals and eating late at night. It is also a kind of ideal diet, just as Shangri-la was a kind of ideal place.”
Seth Roberts, the originator of the Shangri-la diet, is a professor emeritus of psychology at the University of California, Berkeley; he is not a medical doctor or nutritionist. He has said in the course of several television interviews, including a November 2005 segment with Diane Sawyer on the ABC News program Good Morning America, that the Shangri-la diet emerged over the course of some years of self-experimentation coupled with a chance discovery during a visit to France in 2000. With regard to self-experimentation as such, the paper available on the official website of the Shangri-la diet is essentially a discussion of self-experimentation as a potentially fruitful approach to generating topics for further research; it is not a report on the Shangri-la diet by itself.
The hypothesis that there is a mismatch between human evolution and modern life then suggested itself to Roberts as a possible explanation for his difficulties in losing weight. He had already come to accept the so-called set point theory, first proposed in 1950, that weight in human adults is controlled by an internal set point that functions much like a thermostat in a heating system. According to the set point theory, whenever a person's amount of body fat drops below a specific set point, the person's body will eventually regain the fat through increasing appetite, lowering metabolism, or both. Roberts decided to test the set point theory by seeing whether changing his diet could change his body's set point. Over the years he had tried a series of diets—a sushi diet, a pasta diet, a diet that required the dieter to drink five quarts of water per day—but none had proved effective in bringing about permanent weight loss.
On a trip to France in 2000, however, Roberts had a chance discovery that he thinks enabled him to reset his body weight set point. He drank a number of French soft drinks with unfamiliar flavors and lost weight. He theorized that his body did not associate the strange flavors with calorie intake, and that the key to resetting the set point was to break the association that the mind makes between the taste of food and taking in calories. After some experimenting, he came up with the notion that ingesting a small amount of bland or flavorless calories in the form of either an unflavored solution of sugar and water (sweetness has no taste as such) or flavorless liquid cooking oil (he tried canola oil and very light olive oil) could help lower the set point.
The connection that Roberts sees between human evolution and food flavors is as follows: he thinks that human metabolism essentially acquired its present pattern during the Stone Age, when the food supply was highly variable. When food was scarce, the metabolism of our Stone Age ancestors slowed down, lowering their set point to a lower weight and a more efficient metabolism with fewer hunger pangs. When food was once again available in large amounts, people actually got hungrier; they gorged on the food and fattened themselves in preparation for the next period of scarcity. This pattern, according to Roberts, indicates that the human body is programmed to crave more—not less—food when food is readily available so that it can store the extra calories in the form of fat to protect it during the next time of famine.
Roberts went further and hypothesized that this metabolic pattern is accompanied by an association that the brain makes between food flavor and calorie intake. When Stone Age people ate something they found tasty (during a period of abundance) and familiar (which meant that they had found by experience that the food nourished their bodies), their bodies demanded that they eat as much of the tasty food as possible in order to store the extra calories as fat. The problem with modern life in the developed countries is that the constant availability of affordable good-tasting food leads to rampant overeating that is no longer necessary as a protection against hard times, and that food advertising as well as food availability conditions people to associate food flavor with calorie consumption.
The Shangri-la diet in its present form requires the dieter to take either a small quantity of sugar water or a bland oil (extra-light olive oil, canola oil, or highly refined walnut oil) twice or three times a day, at least an hour before or an hour after consuming anything with flavor (including toothpaste or mouthwash). Roberts recommends 1 to 2 tablespoons of oil per day, which comes to 120 to 240 calories. The sugar mixture that Roberts used while losing weight was about 6 tablespoons of fructose (about 275 calories) diluted in a quart of water. According to Roberts, the oil or sugar water gives the dieter some calories in a nutrient-dense substance without flavor, thus breaking the learned association between flavor and calories. In effect, breaking this learned association tricks the body into lowering its set point, suppressing appetite and leading to weight loss without hunger cravings. Roberts suggests taking the doses of oil or sugar water first thing in the morning and just before bedtime, but says that dieters should feel free to experiment and take their doses at other times that may work better for them.
The dieter need not make any other changes in the types of food they prefer. Roberts does, however, suggest ways in which people using the Shangri-la diet can lower their set point even further:
Roberts maintains that he has kept his weight at about 150 pounds by eating one 900-calorie meal per day, 150 calories of fruit sugar dissolved in water, and 2 pieces of fresh fruit (about 75 calories each).
The function of the Shangri-la diet is to induce and maintain weight loss through an approach intended to reset the dieter's set point and improve control of appetite, rather than by eliminating specific food categories or restricting portion size.
There is anecdotal evidence that the Shangri-la diet helps some people lose significant amounts of weight and maintain weight loss. Roberts, who claims to have lost 40 pounds on his diet and kept it off, maintains a website with a forum where people can post success stories.
Some specific benefits mentioned by people who have tried the Shangri-la diet:
According to Roberts, people with diabetes should not use the sugar water option but take only oil if they follow the Shangri-la diet. In addition, people should not use strong-flavored oils, such as ordinary olive oil or flaxseed oil, because the flavors in those oils will prevent breaking the brain's association between flavor and calorie intake.
There do not seem to be any major risks to health associated with the Shangri-la diet, provided that the dieter consumes an appropriate balance of nutrients, vitamins, and minerals, and consults a physician beforehand to exclude the possibility of a previously undiagnosed serious health condition.
One of the major criticisms of the Shangri-la diet is its lack of prepublication clinical testing on a group of subjects. John Ford, an assistant professor of medicine who is highly skeptical of Roberts's claims, notes that Roberts, himself a scholar, should have had more academic integrity. In an online article published in May 2006, shortly after the first press run of Roberts's book, Ford said, “… the scientific method exists for a reason: to root out poor hypotheses and to direct research towards those more likely to be fruitful. If Roberts were truly interested in investigating his approach, he should have subjected it to the dispassionate rigor of clinical study and peer review. His hypothesis is clearly testable with a controlled trial by a careful scientist willing to be proven wrong if necessary. That hasn't happened. Presenting a highly speculative idea as proven science to an audience unlikely to appreciate the difference between an academic psychologist dabbling in this field and seasoned experts who have devoted their careers to it is misleading at best ….”
Ford goes on to point out that the published article that Roberts has posted on his website is not about the Shangri-la diet but rather a speculative essay about self-experimentation as a way to generate ideas for further exploration. Self-experimentation is not necessarily inappropriate as a technique in medicine or nutrition; a recent book on the history of medical self-experimentation devotes a full chapter to physicians who risked their lives testing the role of vitamins in preventing scurvy and other diseases by subjecting themselves to diets lacking these vitamins. The question, however, is whether the results of Roberts's self-experiment with weight control can be generalized to other overweight people. No articles about the effectiveness of or risks associated with the Shangri-la diet have appeared in any peer-reviewed medical or nutrition journal. In addition, the diet has not been endorsed by the Academy of Nutrition and Dietetics or any other professional dietitians' associations. It has, however, been featured in such popular magazines as Woman's World.
One researcher in the field of appetite and taste, however, has been quoted as saying that Roberts's theory about the human mind's association of food flavor with calorie intake is open to question. Dr. Mark Friedman, a physiologist at the Monell Chemical Senses Center in Philadelphia, an independent institute that collaborates on research projects with the University of Pennsylvania, commented in an interview with the Dallas Morning News that “The idea that the taste of food can set food intake and the calories you eat over the long term is an idea that has no scientific evidence.” Friedman allows that research done at Monell does indicate that people tend to like safe, familiar foods and thereby learn certain food preferences. “But that doesn't mean you'll overeat.”
Altman, Lawrence K. Who Goes First? The Story of Self-Experimentation in Medicine. See esp. Chapter 11, “Dietary Deprivations.” Berkeley: University of California Press, 1998.
Roberts, Seth. The Shangri-La Diet: The No Hunger, Eat Anything, Weight-Loss Plan. New York: Penguin, 2007.
“Instant Will Power!” Woman's World, October 3, 2006.
DelVecchio, Rick. “UC Professor's Book Touts Oil and Sugar Solution.” San Francisco Chronicle, May 30, 2006. http://www.sfgate.com/bayarea/article/BERKELEY-UC-professor-s-diet-book-touts-oil-and-2495900.php (accessed April 18, 2018).
ABC News. “Oil and Water: Key to Weight Loss?” Good Morning America, November 14, 2005. http://abcnews.go.com/GMA/BeautySecrets/story?id=1310260#.UGyLIK7bT9Q (accessed April 18, 2018).
Marsh, Stephen R. “Seth Roberts's Shangri-La Diet Reviewed.” CalorieLab Calorie Counter News, April 9, 2006. http://calorielab.com/news/2006/04/09/sethroberts-shangri-la-diet-reviewed (accessed April 18, 2018).
“The Shangri-La Diet.” http://sethroberts.net (accessed April 18, 2018).
Rebecca J. Frey, PhD