Nicole Avena Ph.D.

Food Junkie

World’s Largest Calorie Eating Contest

How you’re a participant without even knowing it

Posted Sep 22, 2014

As children, many of us were taught that we couldn’t leave the dinner table unless we finished what was on our plates. This was a good strategy for parents to ensure that we are getting enough nutrients, but what happens as our plates get bigger?

Food cues can have powerful influences on our decisions. While people often think of food cues as advertisements or savory smells, they can also come in much more subtle forms. In fact, as it turns out, food cues can be divided into two different categories: those that are “sensory” (i.e., smell, taste, even sounds), and - a lesser-known factor - those that are “normative” (i.e., cues that signal how much is appropriate to eat). One example of a normative food cue is portion sizes. We all know that restaurant portions are usually oversized (and may even contain a whole day’s worth of calories), however, portion sizes serve as markers telling us what’s a normal amount to eat. And studies show that we unconsciously tend to match these expectations. In fact, one experiment found that increasing the amount of pasta presented on a plate in a restaurant setting also increased the number of calories that participants ate by 43%. This is also true for drinks; increasing the size of a beverage from 12 to 18 fluid ounces has been shown to lead to increased beverage consumption.

Another great example of the importance of portion sizes comes from research showing that when study participants’ soup bowls were continuously filled - and thus, they were never given the cue to stop eating from the sight of an empty bowl - they ate significantly more soup even though when asked, they did not believe they consumed more. Thus, unconsciously relying on external cues is one way empty calories can unknowingly sneak into your diet.

Unfortunately, portion sizes have increased tremendously over the last several decades, likely contributing to the current rates of being overweight and obese. In fact, recent evidence suggests that eating outside of the home is associated with increased calorie intake. So what can we do? First, we can start by being intentional when we sit down to a meal about how much we want to eat and/or try not to eat out as often. It may even be helpful when at a restaurant to ask for an additional plate or use an appetizer plate to make your own portion size once your meal is given to you. Just being aware of the cues that can influence our intake can make you think twice and consume less.

References:

Herman CP, Polivy J (2008). External cues in the control of food intake in humans: The sensory-normative distinction. Physiol Behav 94(5):722-8.

Diliberti N, Bordi PL, Conklin MT, Roe LS, Rolls BJ (2004). Increased portion size leads to increased energy intake in a restaurant meal. Obes Res 12(3):562-8.

Flood JE, Roe LS, Rolls BJ (2006). The effect of increased beverage portion size on energy intake at a meal. J Am Diet Assoc 106(12):1984-90.

Wansink B, Painter JE, North J (2005). Bottomless bowls: why visual cues of portion size may influence intake. Obes Res 13(1):93-100.

Lachat C, Nago E, Verstraeten R, Roberfroid D, Van Camp J, Kolsteren P (2012). Eating out of home and its association with dietary intake: a systematic review of the evidence. Obes Rev 13(4):329-46.

Appreciation is extended to Ms. Monica Gordillo and Susan Murray for drafting this post.

Dr. Nicole Avena is a research neuroscientist/psychologist and expert in the fields of nutrition, diet and addiction. She has published over 50 scholarly journal articles, as well as several book chapters on topics related to food, addiction, obesity and eating disorders. She recently edited the book, Animal Models of Eating Disorders (Springer/Humana Press, 2013), and she has a book Why Diets Fail (Ten Speed/Crown) that was released January 1, 2014. Her research achievements have been honored by awards from several groups including the New York Academy of Sciences, the American Psychological Association, the National Institute on Drug Abuse, and her research has been funded by the National Institutes of Health (NIH) and National Eating Disorders Association. She has appeared on several television programs, including Dr. Oz, Good Day NY and The Couch.

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