Portion Sizes Can Be Deceptive
It is no secret that as food portions have grown over the
past 20 years, so 
have the waistlines of Americans. How much do these increased portion sizes
really affect how much we eat? The
answer may surprise you.
Portions Larger Than You Think
Portion sizes and serving sizes are different today which
greatly impacts our calorie consumption.
A serving is a standard measure, such as a cup, a half cup, an ounce,
etc. Portion size, on the other hand is
the amount of food offered to a person at a restaurant, in a package, or the
amount someone chooses to put on their plate.
Muffins and bagels are perfect examples of portion
discrepancies. Many times these foods
are sold in sizes that constitute more than one serving. We eat the entire
thing, thinking it was a serving, when in reality the portion may be as many as
four or five servings. YIKES!
Portion sizes may not
matter if a person chooses to eat only a serving rather than the entire portion
they are served, or if individuals eat fewer calories at subsequent meals or
snacks to balance overall calorie intake. However, this isn’t often the case.
Large Servings Are Hard to Resist
Studies show that people do not intuitively assess
appropriate serving 
sizes, they don’t consume the proper serving size when a
larger portion is offered, and they fail to adjust their calorie intake later
in the day to balance out daily calories once they have consumed larger portions.
A study¹ tested how adults responded to different portion
sizes of macaroni and cheese on four different days. They found that the more these adults were
served, the more they ate. In fact, they
consumed about 162 more calories when offered the largest portion compared to
the smallest portion.
In another study², participants were served soup for 3 days and
their intake was recorded. On the fourth
day, they were served soup in trick bowls which refilled from a reservoir
hidden under the table. The people ate
more than their normal serving when the bowls continuously refilled. When the participants were told about the
trick, their intake was then measured for another 6 days. Normal weight individuals adjusted their
intake while the obese participants did not.
Studies done on children have yielded similar results. One in particular³ measured children’s bite
size and intake of an entrée. Intake
rose by 25% with the larger portions than with age-appropriate or self-selected
portions.
Taking Control of Your Portions
Knowing this, it is essential that we become more aware of
how portion size can impact our intake and develop strategies to avoid common
portion pitfalls.
- Start by reading labels and understanding how increased
portions can translate into excess calories. A portion distortion quiz can be found at http://hin.nhlbi.nih.gov/portion
which really illustrates how portions and calorie content of foods have
increased over the past 20 years. Here
you can also find a printable pocket serving size card.
- Manage large portions at restaurants by asking the server to
bring a carry-out container with your meal, ordering smaller portions or splitting
entrées.
- While at home, take steps to control overeating too. Instead of placing serving dishes directly on
the table, dish up reasonable amounts of food on smaller plates. Manage hunger and avoid overeating at meals
by choosing healthy snacks between meals. Resist the urge to eat in front of the TV or
directly from a package.
- Finally, take control of your environment. Make tempting foods and bulk food portions
less visible and available. Remember,
out of sight means out of mind.
¹ Rolls et al. AJCN 2002.
² Pudel and Oetting. 1977.
³Fisher JO, Rolls BJ, Birch LL ,Amer J Clin Nutr
2003;77(5):1164-1170.
