to Stone Age life than to contemporary lifestyle pat-
terns. Roberts believes that humans living in the Stone
Age had most of their contact with other people in the
morning rather than after dark, that they spent most of
the day on their feet, and that the modern preference for
watching late-night television creates a mismatch with
inbred human sleep-wake patterns.
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, loweringmetabolism, or both. Rob-
erts 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
waterper 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 ofFrench 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).
The connection that Roberts sees between human
evolution and food flavors is as follows: he thinks that
human metabolism essentially acquired its present pat-
tern 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 metab-
olism with fewer hunger pangs. When food was once
again available in large amounts, people actually got
hungrier; they gorged on the food and fattened them-
selves 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.KEY TERMS
Anecdotal evidence—A category of medical or diet-
ary evidence based on or consisting of individual
reports, usually written by observers who are not
doctors or scientists.
Association—In psychology, a connection between
two ideas, actions, or psychological phenomena
through learning or experience. The Shangri-la diet
is based in part on the notion that humans eat more
than they need to in the modern world because
of a strong association between food flavors and
calories.
Conditioning—In psychology, the process of acquir-
ing, developing, or establishing new associations and
responses in a person or animal. The author of the
Shangri-la diet believes that modern food products con-
dition people to make an association between the fla-
vors in the foods and calorie intake.
Dietitian—A health care professional who special-
izes in individual or group nutritional planning, pub-
lic education in nutrition, or research in foodscience. To be licensed as a registered dietitian
(RD) in the United States, a person must complete a
bachelor’s degree in a nutrition-related field and
pass a state licensing examination. Dietitians are
also called nutritionists.
Glycemic index (GI)—A system devised at the Uni-
versity of Toronto in 1981 that ranks carbohydrates in
individual foods on a gram-for-gram basis in regard to
their effect on blood glucose levels in the first two hours
after a meal. There are two commonly used GIs, one
based on pure glucose as the reference standard and the
other based on white bread.
Set point—In medicine, a term that refers to body
temperature, body weight, or other measurements
that a human or other organism tries to keep at a
particular value. The Shangri-la diet is said to work
by lowering the dieter’s set point for body weight.
Shangri-la—A utopia; a mythical place in the Hima-
layas where life approaches perfection, depicted in a
1933 novel by James Hilton.Shangri-la diet