Modernist-Cuisine-Vol.-1-Small

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Body mass index (BMI) is a measure
of weight (in kg or lb) relative to
height (in m or in) that roughly
approximates body fat. The
formulae are
BMI = kg ÷ m²
BMI = lb × 703 ÷ in²
The World Health Organization
classifies BMI into four categories.
BMI
Classification
<18.5 underweight
18.5–24.99 normal weight
≥25
≥30
overweight
obese
NONMEDICAL DIETARY
SYSTEMS
Some dietary systems are adopted more often for
ethical or aesthetic reasons than for medical ones.
Low-fat and low-carbohydrate diets are among the
most popular of myriad approaches for losing
weight. Vegetarian and organic foods are increasingly
popular as well, both separately and in
combination.
Like medical dietary systems, nonmedical
dietary systems are promoted by marketers and
advocates. Adherents to these diets often believe
fervently in the health and lifestyle benefits of
their choices, despite a lack of reliable scientific
evidence to back those beliefs.
The largest controlled clinical trial of weight
loss plans conducted to date, for example, concluded
that any dietary system will help you lose
weightas long as it provides fewer calories than
your usual fare. The trick to weight loss, however,
isn’t in shedding the pounds but in keeping them
off. This same study found that participants began
to gain weight back after just one year.
But science offers some good news as well:
carrying a modest amount of extra weight may not
be as bad for you as we’ve been counseled to
believe. A 12-year prospective study of more than
11,000 adults found that those who are technically
classified as overweight according to their body
mass index were slightly less likely to die of any
cause than their peers of so-called “normal”
weight. Underweight people were 73% more likely
to die than those of normal weight. A bit of
padding may give people, especially the elderly,
the reserves they need to cope with the metabolic
demands of fighting disease.
Weight Loss Diets
The promise of weight loss drives a major industry
that takes in billions of dollars in revenue each
year in the United States alone. Over the years, in
a pattern that is similar to the rise and promotion
of medical dietary systems, scores of weight loss
plans have been published and marketed.
No one has taken credit for authoring the
archetypal plan: the grapefruit diet, which has
been in circulation since the 1930s. It was touted
as a quick, short-term way to lose weight. Although
the premise is that drinking grapefruit
juice or eating the fruit combined with protein
promotes weight loss, the dietwhich restricts
carbohydrates to vegetables and grapefruitaverages
so few calories per day that most people will
inevitably lose weight in the short term.
One small study has shown that the addition
of grapefruit to one’s diet might be more than
old-time lore: 91 obese patients with metabolic
syndrome were randomized to take either
placebo or grapefruit in various formscapsule,
juice, or freshfor 12 weeks. Everyone who
consumed grapefruit lost weight and had improved
insulin responses after eating (meaning
their bodies more appropriately drew glucose
from their blood into their cells), but those who
ate half a fresh grapefruit before each meal lost
the most weight (1.6 kg / 3.6 lb over three
months) and had the best postmeal insulin
profile. The authors note that half a fresh grapefruit
has fewer calories than the quantity of
grapefruit juice that the subjects drank and more
fiber, which promotes a feeling of fullness. The
acidity of grapefruit may also keep food in the
stomach longer, delaying the return of hunger.
The Shangri-La diet, developed by a psychologist,
supposes that foods that are familiar and rich
will prompt the brain to crave more of them,
leading to weight gain. Foods that are unfamiliar
and bland will trick the brain into thinking food is
scarce, thus lowering the body’s “set point,” or
weight that it naturally maintains.
The trick (according to the story) is to consume
a few tablespoons of fructose water or
extra-light olive oil between meals. The diet’s
author alleges that this step, which provides
calories but little taste, retrains the mind so that
it no longer associates calories with taste and
thus craves food less often. So far, however, the
only evidence supporting the idea comes from
experiments with rats.
Weight Watchers
A much more robust set of studies has looked at
Weight Watchers, one of the most enduring diet
programs. Initially just an informal support
group, Weight Watchers has developed into
a multifaceted, multitrack weight loss plan. Many
nutrition experts approve of Weight Watchers
because it stresses that weight loss and maintenance
require long-term lifestyle changes,
including more physical activity, and it teaches
the skills and provides ongoing support for those
changesaddressing the psychosocial as well as
the physiologic facets of weight loss.
Unlike many other weight loss systems, Weight
Watchers does not eliminate or overly restrict any
food or food group, so adherents claim to feel less
deprived. Users can count calories with the help of
several tools that assign proxy values (Weight
Watchers’ trademarked Points system), including
an online portal, or they can use a new program
that permits unlimited consumption of “filling
foods” from all the food groups.
A 2008 study tracked down a random sample
of successful Weight Watchers participants who
had met their weight loss goals and achieved
lifetime membership status. Upon weighing
these participants, the investigators found that
half had maintained at least 5% of their weight
loss after five years, and one-sixth (16.2%)
remained below their goal weight at the five-year
mark. The authors of the study note that these
results far exceed those found in most randomized,
controlled trials of lifestyle changes for
obesity treatment. But that may be due largely to
the fact that study subjects were recruited from
only the most successful subgroup of Weight
Watchers members.
Rich with vegetables, beans, nuts, olive oil, and
whole grains, the Mediterranean diet has been
linked in observational studies with a high
quality of life and low rates of chronic disease.
A recent meta-analysis of observational studies of
the Mediterranean diet concludes that those who
adhere to it enjoy significant reductions in overall
mortality, death from heart disease, incidence of
and death from cancer, and incidence of Parkinson’s
and Alzheimer’s disease.
The diet is less clearly responsible for weight
loss: a review of studies revealed just one that
associated the Mediterranean diet (35% fat,
calorie-restricted) with weight loss, compared
with a low-fat (20%), calorie-restricted diet with
the same calories (1,200–1,500 per day). After 18
months, the Mediterranean diet group had lost
an average of 4.8 kg / 10.5 lb, while those in the
low-fat group had begun to gain back their initial
impressive weight loss (an average of 5.1 kg /
11.2 lb) to average a 2.9 kg / 6.4 lb loss.
Investigators in the Nurses’ Health Study
II, a long-term prospective study, assessed
the weight loss success of young and
middle-aged women. More than half of the
women who lost more than 10% of their
body weight gained it all back.
NURSES’ HEALTH STUDY II
Studied outcome: long-term weight loss
Study duration: six years
Participants: 47,515
Results: 2,590 lost >5% of body weight
5.5% lost more than 5% of body weight
Of those 2,590 women, 1,204 (46.5%) regained,
within 5 years, all weight lost
Results: 1,326 (2.8%) lost >10% of body weight
Of those 1,326 women, 751 (56.6%) regained,
within five years, all weight lost
The Nurses’ Health Study II also suggested
the more weight women lost, the more
they regained compared with their peers.
Weight-stable women were more likely to
use exercise for weight control than
nonweight-stable women; cyclers were
more likely to diet than noncyclers.
NURSES’ HEALTH STUDY II
Studied outcome: long-term weight change
after multiple cycles of weight loss and regain
Study Duration: eight years
Participants: 544 women who remained
weight-stable from 1989–1993
741 mild cyclers who lost ≥4.5 kg / 10 lb three
times from 1989–1993
224 severe cyclers who lost ≥9 kg / 20 lb three
times from 1989–1993
Results: women who were weight-stable from
1989 to 1993 had gained the least weight by
2001; women who were severe cyclers gained
the most weight
Weight gain, 1993–2001:
46.5% regained it
2.8% lost more than 10% of body weight
2.7 kg / 5.9 lb
Weight-stable women
Mild weight-cyclers
6.9 kg / 15.2 lb
Severe weight-cyclers
8.5 kg / 18.8 lb
56.6% regained it
240 VOLUME 1 · HISTORY AND FUNDAMENTALS
FOOD AND HEALTH 241