The Secret History of the Shangri-La Diet

Seth Roberts

Tsinghua University

17 October 2008

Why Shangri-La?

The term Shangri-La is from the novel Lost Horizon (1933) by James Hilton. In the novel, Shangri-La is a very peaceful place hidden in the Himalayas. The Shangri-La Diet puts people at peace with food: They stop thinking about it so much.

Outline of talk1. Relation to psychology & China2. What’s the diet?3. Getting there

1. Background: The setpoint theory of weight control2. A mysterious result3. Background: Smell-calorie associative learning4. A new theory of weight control5. Two self-experiments6. An accident in Paris

4. Book Publication5. The Future

Connection with Psychology

• The diet came from a new theory of weight control. At the heart of that theory is Pavlovian Conditioning: learning to associate signals and food. (Pavlov’s dogs learned that a bell signaled food.)

• My specialty area in psychology is animal learning. This is why I managed to think of the theory.

Connection with China

• In tradition of useful academia. Shows how psychology research by professors can have practical value.

• Increasing obesity in China. “Fast catching up with the West.” As countries become better off, obesity becomes more of a problem. This talk: new idea about what causes obesity.

Copyright ©2006 BMJ Publishing Group Ltd.

Wu, Y. BMJ 2006;333:362-363

Overweight and obesity in schoolchildren in large cities in China

How To Do Shangri-La Diet

• General idea Eat or drink calories without smell between meals.

• Details 4 common ways: 1. Drink unflavored sugar water (which has no smell). 2. Drink oil with no smell (such as extra-light olive oil). 3. Eat any food with nose held shut. 4. Drink flaxseed oil (high in omega-3) with nose held shut.

• Daily dose: 4 times your weight in kg. E.g., if your weight = 80 kg, eat 320 kcal this way.

• No deprivation. Continue to eat your usual food, as much as you want. Effect of diet: less hunger, feel full faster, eat less than usual.

Background: The Setpoint Theory of Weight Control

• Body weight is very stable. Why?• In 1950s, a scientist proposed that body weight is kept

constant by a system with negative feedback, similar to how a thermostat controls room temperature.

• Your setpoint is the weight your body tries to maintain. Setpoint = target weight.

• If you lose weight – go below your setpoint -- you become hungrier, eat more, regain lost weight. If your weight goes above your setpoint you become less hungry than usual, lose weight.

• Not surprising. Many biological variables, such as blood sugar and body temperature, regulated this way.

• Doesn’t explain obesity

A Mysterious Result

• Israel Ramirez, American scientist, published 1990

• Will saccharine make rats gain weight?• Expt 1: Add saccharine to liquid diet. Result:

Causes weight gain.• Expt 2: First, test saccharine preference.

Second, add saccharine to liquid diet. Result: No weight gain.

• Huh? Expts 1 & 2 had almost the same procedure but results were different.

A Mysterious Result (cont.)

• Expt 3: 3 groups of rats. – Group 1. Baseline: No saccharine. – Group 2. No Pretest. Saccharine added to food. – Group 3. Pretest. Pretest plus Saccharine added to

food.

• Result: No Pretest > Pretest = Baseline. Exposure to saccharine eliminated the fattening effect of saccharine.

• Mysterious: Results suggest how fattening a food is depends on experience with the food. A puzzling new idea.

Background: Smell-Calorie Associative Learning

• We learn to associate smells of food with calories in food.

• When smell and calories occur together, our reaction to smell changes. The smell (part of the flavor) becomes more pleasant. An example of Pavlovian learning. Pavlov’s dogs began to salivate to bell followed by food.

• The stronger the smell-calorie association, the better food tastes. As we learn this association, food tastes better. When food is new, before this association is learned, food tastes strange, like medicine.

New Theory of Weight Control

• Central idea: Your setpoint depends on how strongly smell of your food associated with calories. Stronger association higher setpoint.

• Assumption 1: Smells associated with calories raise setpoint.

• Assumption 2: Between meals, setpoint goes down.

Why? Evolutionary Reason

• All storage systems: low price stock up. Fat: food cheap store more fat. We should gain weight when food is plentiful.

• When we have choice of food, we choose the food that tastes the best. Strong smell-calorie associations make food taste good.

• When we eat food with stronger smell-calorie associations, it means we had more choice. More choice food more plentiful. Thus the strength of smell-calorie associations in what we eat is correlated with food abundance. Stronger associations food more abundant

Two Self-Experiments

• Prediction: Food with weak smell weight loss. (Weak smell weak smell-calorie association.) Result: Eating lots of sushi, I lost 6 kg.

• Prediction: Food with slowly-digested calories weight loss. (Slowly-digested calories weak smell-calorie association.) Result: Eating lots of lentils and beans, I lost 3 kg.

• These results made me start to believe my theory, because it made correct predictions.

An Accident in Paris

• Visited Paris in 2000. After a few days, huge loss of appetite for no obvious reason. Why?

• What was different? Not sick. Not upset. No unusual exercise. No unusual food, except one thing: Because of hot weather, drinking soft drinks with sugar every day. I usually drank soft drinks without sugar (with artificial sweetener).

• Could soft drinks with sugar cause loss of appetite (and thus weight loss)?

An Accident in Paris (cont.)

• Was drinking soft drinks with flavors new to me. Theory said because smell (flavor) was new, not yet associated with calories. Food with smell not associated with calories should cause weight loss.

• Astonishing idea: Soft drinks with sugar always believed to cause weight gain.

• After I returned home, tested idea that unflavored sugar water (which has no smell) causes weight loss.

Long-lasting Weight Loss

Shangri-La Diet Publication Facts

• Published 2006 by Putnam, a mass-market division of Penguin

• On New York Times bestseller list one week

Mixed Reviews• “I am 95% sure that Seth Roberts is a

snake-oil salesman” -- Washington Post• “Absurd” – Toronto Star• “A case study in fad dieting” – Elle• “One of the most unusual weight loss

books ever written” -- Diet-Blog.com• “Unlike any diet you ever have come

across” -- Health-Hack.com

Cartoon Treatments

The Important Effects

1. Countless reports of food obsessions quickly disappearing, amazement.

2. Countless reports of weight loss.

Unique Results

• “I'm on Day 5. I CANNOT BELIEVE THAT THIS WORKS!!!!  I told my sister about it and while she scoffed at first she's on Day 2 and as ecstatic as I am.  My appetite is a fraction of what it used to be . . . I could cry.”

• “I had a completely unique experience yesterday. While out for a lunchtime walk, I stopped at McDonald's and grabbed a side salad and a small fries to go with my lunch. I got back to my office and got distracted. By the time I remembered and went for the fries they were completely cold and I only had a few before tossing the rest. I have never "forgotten" about McDonald's fries before.”

Unique Results (cont.)

• “It's amazing not to feel my hunger increasing as I lose weight. The whole experience of weight losing is different. Usually it is like holding your breath underwater—the longer you go without air, the more massively you need air. Usually the longer you are on a diet the more hungry you are. This is so strikingly different.”

Example of Weight Loss

The Future: Where Are We Now?

• A new theory of weight control. Based on earlier research in a non-trivial way. Explains puzzling results. Makes several predictions that no other theory makes. Suggested new ways of losing weight that worked.

• Unique phenomenology. The new ways of losing weight reduced food obsession more than other diets.

• Many single examples of weight loss.

The Future: Where This Might Go

• Animal experiments. Test predictions of theory. For example, does sugar water cause rats to lose weight?

• Short-term human tests. Carefully measure loss of hunger and reduced thinking about food. What do these effects depend on?

• Clinical trials. Compare Shangri-La Diet to other diets and weight-loss methods.