Download portion size and caloric intake

PORTION SIZE
AND CALORIC
INTAKE
Portion sizes have increased dramatically in the last
half century: The archetypical 6.5-ounce sugarsweetened beverage from the 1950s has given way
to bottles of 20 ounces or more. And as Morgan
Spurlock graphically illustrated in his movie, Super
Size Me, restaurant portions have also ballooned to
lure in “value” customers. Indeed, the rate of new,
larger portion-size introductions among a sample of
common commercial products increased by more
than a factor of 10 from 1970 to 1999—the period
when obesity rates increased most rapidly—
driven predominantly by the exceedingly low cost
of commodities.
Although it seems intuitive to link the larger portions
to Americans’ growing waistlines, the relationship
between calorie quantity and quality must be
carefully considered, to ensure that changes in
portion size produce real benefits.
Extensive research demonstrates that for many
individuals, larger portions lead to more calories
consumed over the short term. However, there is
little evidence that changes in total calorie intake,
independent of dietary quality, have a meaningful
long-term effect on body weight. When lean or
obese individuals were under- or overfed to change
body weight by 10 percent, energy expenditure
decreased or increased, respectively. In addition,
after a period of forced overfeeding, research
volunteers decreased food intake until original
body weight had been restored. In short, body
weight appears to be under strict long-term control
by biological factors, and the body’s metabolism
responds to resist weight change.
Genetic make-up helps to explain individual
differences in predisposition to obesity. But in the
focus on calories in and calories out, the importance
of modifiable environmental factors, especially diet
quality, is often lost. This is especially problematic
because diet quality strongly influences individuals’
risks for diabetes, heart disease, and other
degenerative conditions associated with the Western diet.
There are many modifiable biological drivers of
body weight, but the most important are hormones
in general, and insulin in particular. States of high
insulin secretion are characteristically associated
with weight gain (e.g., excessive insulin treatment
in type 2 diabetes), whereas reduction of insulin
levels causes weight loss (e.g., inadequate insulin
administration in type 1 diabetes). Diet has a major
impact on insulin secretion, predominantly related
to the total amount and type of carbohydrate
consumed. Highly processed starches and added
sugars have a high “glycemic index” and inordinately
raise blood sugar and insulin levels.
Trans fat used to top the list of public health
enemies. Happily, in recent years trans fat has
been largely eliminated from the food supply.
Today, increased focus on the type and amount
of carbohydrates is needed. A strong case can
be made that increasing the portion size of refined
starchy foods (e.g., extruded breakfast cereals,
bread, white rice, pasta, fries) and added sugars
(e.g., sugar-sweetened beverages, highly sweetened
desserts) erodes diet quality and leads to chronic
disease. Conversely, increasing the portion size
and serving frequency of minimally processed
carbohydrates (vegetables, fruits, legumes), healthful
fats (nuts, avocados, oil-based salad dressings), and
plant-based proteins (nuts, legumes, soy products)
displaces less healthful foods, improves diet quality,
and protects against chronic disease.
require simultaneous restructuring in national food
policy, to increase the amount of these products in
the food supply, and to lower their cost relative to
commodities.
IN SUMMARY:
• All calories are not alike, so it is critical to
complement the current focus on portion size
with a shift in our cultural thinking on diet quality.
• Now that trans fat has been largely eliminated
from the food supply, the leading dietary cause
of obesity and related complications is highly
processed carbohydrates—not just sugar but
also refined grains and potato products.
SCORE: 3
Efforts to reduce calories continue to move in a
positive direction: away from the low-fat paradigm
and toward an emphasis on low-sugar and smaller
portion size. This constitutes progress, but a more
fundamental focus on food (or calorie) quality, not
just quantity, is needed.
• To increase consumption of minimally processed
carbohydrates, healthful fats, and plant-based
proteins, shifts in national policy are needed
to decrease prices of these foods relative to
commodities, as are culinary strategies from
the foodservice industry to make these options
more available on menus and served in a
delicious variety of ways.
All calories are not alike. The belief that they are has
produced misguided attempts to modify the food
supply and led to confusion and indecisiveness
about what to do within the culinary profession
and the foodservice industry. Simply lowering the
total calories in a meal by reducing fat content will
not lead to lasting benefit, if that meal is less than
satisfying and leads to subsequent overeating.
RECOMMENDATIONS:
The foodservice industry has an unprecedented
opportunity to help end the epidemics of obesity
and related diseases. However, a paradigm shift is
needed. Measures that only reduce calories, without
enhancing the quality of those calories, are destined
to fail. Instead, the focus should be on serving more
minimally processed carbohydrates, healthful fats,
and plant-based proteins, while simultaneously
reducing high glycemic index carbohydrates. The
goal is to make healthy foods in appropriate portion
sizes the most appealing options. These changes will
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