How Portion Sizes Affect Your Appetite

My husband hates restaurants that serve "nouveau cuisine" because he says they serve "small pretty food" that leave him hungry. When he has no choice but to eat at such a restaurant because we are meeting up with friends, he usually asks for two or three orders or he eats again afterwards at home. And yet, he is satisfied with airline food, which has about the same size and amount of food at those restaurants. What's the difference? The difference is in the size of the plates. The airline food is served in small containers while nouveau cuisine food is usually served in extra large plates. The airline food looks like an "appropriate" serving size in my husband's eyes because it fills up the entire tray while the large restaurant plate makes the food look like a tiny portion. This is an example of "portion distortion", which is a phrase coined by Brian Wansink, a consumer psychology expert at the University of Illinois to describe how our eyes can fool our stomach.

Here is another example. Whenever we go to the U.S., both my husband and I are shocked at the gigantic portions served at most restaurants so we split the meals between us. But then a funny thing happens as the days pass. The serving sizes no longer look as big and we don't want to share our food anymore. We have to consciously tell ourselves that the portion sizes are unrealistic and that our bodies don't need all that food. But left on our own, our eyes and consequently our stomachs would quickly get used to those extra large portions.

This isn't just a personal observation of how portion sizes can affect our appetite. Wansink has proven in various experiments that the more you are served, the more you will eat.

Study participants who were given larger scoops of ice cream ate ten percent more compared to participants who were allowed to scoop their own ice cream. People who were given large plates at a party ate much more than people who were given regular sized plates. Wansink says that people lose track of how much they eat when they are given large portions or plates. Now you know why some eat-all-you-can restaurants give you small plates - to control your appetite. They know from experience that people will fill up whatever size plate they are given regardless of how hungry they really are.

In an experiment with trick soup bowls, participants who ate out of bowls that were automatically refilled by an unseen tube under the table ate 40 to 70 percent more soup. They couldn't tell how much they were eating because the soup bowl just kept refilling without their knowing it. Wansink says that when you are served a very large portion, you can't tell after a while if you have eaten half of it or two-thirds of it. We need visual cues to remind us that we have eaten enough.

In another experiment at a party, Wansink's research team left chicken bones on some tables while they removed the bones from other tables at regular intervals. Afterwards, they weighed each table's bones to see which group ate the most. The groups that did not see the chicken bones around them as they were eating ate 24 percent more than the groups that could see the "proof" of how much they had eaten.

Physiologist Barbara Rolls of Penn State University has done her own research to prove that portion size can stimulate appetite. In one study, lean young men were served different portions of macaroni and cheese for lunch on three separate days. The men ate ten ounces when they were served a 16-ounce portion, 13 ounces when they were given 22 ounces, and 15 ounces when they were handed a 25-ounce serving.

The influence that large portions have on a person's appetite is one reason that Americans are getting bigger, according to nutritionists. Restaurants and fast food chains offer super-sized versions of their products for a very small increase in price. Consumers have gotten used to these large portions and now consider them to be normal. This is another example of portion distortion. That's why we Pinoys are surprised at the portion sizes when we go to the U.S. We are comparing the American size, which is actually abnormal, with our typical Pinoy serving, which is closer to a normal size serving. However, at the rate that our country is being "invaded" by foreign food chains and if our local restaurants will play copycat, we could eventually become as overweight as many Americans if we get used to those enormous portions. Like nutritionist Marion Nestle of New York University said, "Super-sized portions can create super-sized people."

It's not just portion sizes in restaurants that you have to be careful of. You also have to watch the portion sizes that you serve at home, especially with children.
This propensity to eat more when we are given larger portions is something we learn as we grow up. According to Rolls, babies and toddlers are not affected by portion size. It doesn't matter how much you try to serve them, they stop eating when they are full. Anyone who has ever forced a baby to eat when he or she doesn't want to knows what it feels like to have baby food all over their face and hair.

Rolls did an experiment with three and five year old kids to see which of the children would be influenced by the portion size served to them. She discovered that the younger children stopped eating when they were full regardless of the portion size served. The older children responded like the adults in her other experiments. The bigger the portion, the bigger the amount they ate.

In a chat on WebMD, Rolls explained that young children respond to their physical hunger while older kids, like adults, react to external cues. She believes that many parents condition their children to eat more with the "clean plate" and "think-of-the-starving-kids-in-Africa" mentality. Here is her advice to parents: "We start off as children with the ability to recognize hunger and respond to it, but much of what happens to us in our eating environment undermines this ability. What I think people need to do, and what parents need to do with their kids is let them decide for themselves how much food they should take and put on their plates to satisfy their hunger. We find in studies in our lab that when people serve themselves from a family style meal, they take appropriate portions, and eat a very constant weight of food over the day. If you depend on somebody else to serve you, you will probably end up affected by the amount they give you. But if you allow yourself to choose how much you want to eat, you'll probably do better in the long run."

Lastly, we need to be aware that large-sized packaging can also have an influence on how much food we cook and serve. In an award-winning research study that was quoted in the Wall Street Journal and the Harvard Business Review, Wansink showed that a larger package size can accelerate the usage of the product by 7 to 43 percent. Study participants who were told to prepare a dinner for two pulled out 29 percent more spaghetti noodles when using a larger box and poured 23 percent more oil to fry chicken when using a larger bottle. This unnecessary usage applies to other household products as well. Homemakers, take note. If you or your household help are anything like the participants in Wansink's study, you will use eleven percent more detergent from a large box compared to a small one and 9 to 36 percent more from a sale-priced liquid cleaner bottle compared to a regular-priced one. The underlying reason why people act this way is because they believe they are getting a bargain when they buy the larger sized and sale-priced products so they aren't as careful about how much they use.

When it comes to non-edible household products, the only thing that will suffer is your wallet, but when it comes to large food portions, it is your health and weight that will have to bear the consequences. Here are some practical tips to avoid the bigger-is-better syndrome:

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