The discussion of portion sizes was based on an unstated assumption that
I fundamentally disagree with.

The assumption is that restaurants are the source of the problem.

People still eat at home more than they eat out.  Eating large portions
at home is a personal choice, fully under your control as to how much
you put on your plate, and how much you actually eat.  

When I was hosting Japanese exchange students, part of the cultural
training was around food.  We were taught that Japanese students would
take much smaller portions than we did.  

It is a shared cultural value:  Americans, in general, eat larger
portions than the Japanese, in general.  We were asked not to force our
values on the Japanese students by urging them to eat more or take
larger portions.  And we were told not to worry about them not getting
enough to eat.  

It is clear that the "forcing" is coming from individuals, especially
adults who are transmitting cultural norms every time they make
value-laden statements about  taking more, about your portion being too
small, etc. 

If people were leaving food on their plates, restaurants would serve
smaller portions.  Good chefs are always looking for ways to save money,
and this is one of the easiest.  

So, I think the question needs to refocus.  When did Americans start
eating large portions?  What cultural factors would lead to an
culturally transmitted obesity epidemic, where simply knowing obese
people increases the chance that you will become obese?  (The abstract
of the article is included in reply #1.)

One connection might be the conspicuous consumption patterns that
started in the post-war era.  Food is then one of many items that we
over-indulge in.

The American Depression in the 30s and 40s may also be having a
lingering influence.  Perhaps we are eating to ward against the specter
of poverty.  

Or perhaps it is a control issue.  Eating diseases like bulimia,
anorexia, and obesity have blossomed in the past 50 years.  What is the
connection here?  

To simplistically lay the blame on restaurants misses the power of
culture on our personal choices.  How *did* we get here?  

12 responses total.

The Spread of Obesity in a Large Social Network over 32 Years
Nicholas A. Christakis, M.D., Ph.D., M.P.H., and James H. Fowler, Ph.D.

ABSTRACT

Background The prevalence of obesity has increased substantially over
the past 30 years. We performed a quantitative analysis of the nature
and extent of the person-to-person spread of obesity as a possible
factor contributing to the obesity epidemic.

Methods We evaluated a densely interconnected social network of 12,067
people assessed repeatedly from 1971 to 2003 as part of the Framingham
Heart Study. The body-mass index was available for all subjects. We used
longitudinal statistical models to examine whether weight gain in one
person was associated with weight gain in his or her friends, siblings,
spouse, and neighbors.

Results Discernible clusters of obese persons (body-mass index [the
weight in kilograms divided by the square of the height in meters],
≥30) were present in the network at all time points, and the
clusters extended to three degrees of separation. These clusters did not
appear to be solely attributable to the selective formation of social
ties among obese persons. A person's chances of becoming obese increased
by 57% (95% confidence interval [CI], 6 to 123) if he or she had a
friend who became obese in a given interval. Among pairs of adult
siblings, if one sibling became obese, the chance that the other would
become obese increased by 40% (95% CI, 21 to 60). If one spouse became
obese, the likelihood that the other spouse would become obese increased
by 37% (95% CI, 7 to 73). These effects were not seen among neighbors in
the immediate geographic location. Persons of the same sex had
relatively greater influence on each other than those of the opposite
sex. The spread of smoking cessation did not account for the spread of
obesity in the network.

Conclusions Network phenomena appear to be relevant to the biologic and
behavioral trait of obesity, and obesity appears to spread through
social ties. These findings have implications for clinical and public
health interventions.

From the article:

The prevalence of obesity has increased from 23% to 31% over the recent
past in the United States, and 66% of adults are overweight.1,2 Proposed
explanations for the obesity epidemic include societal changes that
promote both inactivity and food consumption.3 The fact that the
increase in obesity during this period cannot be explained by
genetics4,5 and has occurred among all socioeconomic groups1 provides
support for a broad set of social and environmental explanations. Since
diverse phenomena can spread within social networks,6,7,8,9,10 we
conducted a study to determine whether obesity might also spread from
person to person, possibly contributing to the epidemic, and if so, how
the spread might occur.

Whereas obesity has been stigmatized in the past, attitudes may be
changing.11,12 To the extent that obesity is a product of voluntary
choices or behaviors, the fact that people are embedded in social
networks and are influenced by the evident appearance and behaviors of
those around them suggests that weight gain in one person might
influence weight gain in others. Having obese social contacts might
change a person's tolerance for being obese or might influence his or
her adoption of specific behaviors (e.g., smoking, eating, and
exercising). In addition to such strictly social mechanisms, it is
plausible that physiological imitation might occur; areas of the brain
that correspond to actions such as eating food may be stimulated if
these actions are observed in others.13 Even infectious causes of
obesity are conceivable.14,15

We evaluated a network of 12,067 people who underwent repeated
measurements over a period of 32 years. We examined several aspects of
the spread of obesity, including the existence of clusters of obese
persons within the network, the association between one person's weight
gain and weight gain among his or her social contacts, the dependence of
this association on the nature of the social ties (e.g., ties between
friends of different kinds, siblings, spouses, and neighbors), and the
influence of sex, smoking behavior, and geographic distance between the
domiciles of persons in the social network.

Hmm, this is an interesting study.  I wonder about the other forms of
eating patterns  compare [like the previlance of anorexia, bulimia,
compulsive eating, etc].  

And where have the actual cultural changes come from? I can definitely
see how things  can change in situations like the depression era.  And
with improved[?] ways of food  availability [food storage, food
perservation techniques, the increas in the size/selection  of  specific
foods in grocery stores and markets, etc]?  And, as briefly mentioned in
 another item, how much does the media influence eating behaviours
[advertising sweet  cereals to kids during prime kid's programming, high
fat snacks to targetted adult  populations, etc] as well as media's
concept of acceptable or preferrable body-type  and/or preferences/norms
relating to body size, appearance [all of those commercials/ ads for
make-up, fashion, etc] and such?  This can and does promote eating [and 
exercise] disorders among certain populations.

And all of the magazines in bookstores and in check-out lines at the
store--always  advertising recipes for high-fat or high-sugar foods
along with the newest trends in diet  plans...  

The notes propose three possible ways obesity might be spreading:

Social mechanisms, such as they investigate in this article.

Physiological imitation, where areas of the brain are stimulated by
observing other's behavior.

Infections, which calls to mind the "ulcers phenomenon", in which the
food ingested was blamed for what turned out to be a bacterial
infection.

A fun quiz based on the USDA 1800 calorie diet.  

Can you match the correct portion size with its food group?

http://www.cookinglight.com/cooking/hl/nutrition/whitepage/0,15829,122868
0,00.html

Watch the cut-off url. 

Ok, the dairy surprised me, but then, I tend to throw dairy and meats 
all into the same group in terms of nutrition.

Here's an interesting link to the Japanese government's information on
portion sizes (it's an English translation, actually).

A bento box is a lunchbox, essentially.  Because the visual aspect of
nutrition is so important in Japan, people take a great deal of care in
arranging to-go meals in attractive containers and in attractive
patterns.  

"In Japan, bento box size is described not by its dimensions (inches or
centimeters), but instead by its volume or capacity (in milliliters  
ml). Why? Because a rule of thumb in Japan is that when you pack a bento
box normally (A: 3 parts grain dishes, 1 part protein dishes, 2 parts
vegetable dishes; B: without candy, junk food or fatty food; and C:
without empty space), calories correspond directly to capacity. So a
600ml box should hold a 600-calorie meal."

This link:
http://lunchinabox.net/2007/03/07/guide-to-choosing-the-right-size-bento-
box/

will help you figure out what size bento box the government suggests you
use.  

I'm intrigued by the idea of choosing a plate or bowl that holds the
correct number of calories/milliliters, and then filling it in the 3:2:1
pattern for a meal.  

Essentially, you would use half the space for the grain, then 2/3 of the
remaining space for vegetables, and the remaining 1/3 (of the 1/2) for
protein.  

Neat trick.  I'm off to measure the mL capacity of all my favorite bowls
and boxes.  (Yes, I already own several bento boxes).  

BTW there is a flickr group that photographs their bento boxes and posts
them.  
http://www.flickr.com/groups/bentoboxes/

another one of those cut-off urls.

A friend of mine, on LJ, has been putting together bentos for herself
and her mother, and taking pictures of them. They're rather interesting.

We frequently cook 3 parts grain and 1 part beans together, then eat with
stir-fried or stewed or microwaved or saladed vegetables.

I love the idea of bento boxes. It seems to me that one could prepare
2-3 days worth at once and then have easy lunches. I was thinking that a
good one would be brown rice, celery sticks, and bbq shredded chicken or
something. 

Response not possible - You must register and login before posting.

- Backtalk version 1.3.30 - Copyright 1996-2006, Jan Wolter and Steve Weiss