Eat Drink Better

Published on June 21st, 2012 | by Mary Gerush


Portion Control: A Behavioral Psychologist’s Perspective

Fresh Apple On The Branch

We know we should eat reasonably-sized portions — so why don’t we?

Matt Wallaert, a scientist and behavioral psychologist who studies why we make the food choices we do, shared some valuable tidbits recently when he was interviewed by NPR’s Renee Montagne. New York City’s plan to ban large sodas prompted the interview, but a few of Mr. Wallaert’s comments are more broadly relevant given our heightened attention to managing the volume of our food intake.

I encourage you to listen to the original interview, but if you’re short on time, these are the nuggets that magnified themselves when I first read the transcript:

  • The food scarcity that affected our ancestors influences our behaviors today. Back in the day, it was difficult to find, harvest, and prepare food, so our ancestors learned to eat as much as they could when they had the opportunity, not knowing when their next meal would present itself. Apparently, we haven’t evolved much in our approach to eating: We are genetically programmed to bring in as many calories as we can when those calories are available — whether we need them or not.
  • We exhibit a behavior called “unit bias” when it comes to eating. You don’t eat 3/4 of an apple — you eat the whole thing. As Mr. Wallaert states in the NPR interview: “The unit is an apple. So you eat an apple.” Apparently, you can apply the same logic to a bag of chips. A bag of chips is a bag of chips! Add 20% more, and it’s still a bag of chips, which we perceive — and are likely to consume — as a single unit.
  • We’re in the market for a deal, regardless of what it means to our waistline. When a fast food restaurant offers a large sandwich for $1 more than one half its size, we tend to supersize. Frugality is baked into our DNA. Pair that with “unit bias” (which makes us eat the excess food instead of packing up leftovers), and portion control loses out to the deal of the day.

My big takeaway from this short interview isn’t surprising: We should eat more consciously! We should consider each bite, relish every taste, eat only what we want, and save the rest for tomorrow’s lunch. So why don’t we? It’s up to us to figure that out.

Read more about making better food choices:

Got tips for eating consciously? Bring ’em on, and share with our readers!

Image credit: iMaffo via flickr/CC license

Keep up with the latest sustainable food news by signing up for our free newsletter. CLICK HERE to sign up!

Tags: , , , , , ,

About the Author

Hi all! I'm Mary Gerush - a recovering corporate worker bee turned good-farm-real-food advocate and writer who wants to help people understand what they're eating. I tend a tiny urban farm in Dallas, TX, and hope to scale up one day soon. Omnivore through-and-through, there's not much I love to eat more than a butter-basted grass fed steak fresh from a searing hot cast iron skillet. Follow me on , , and !

2 Responses to Portion Control: A Behavioral Psychologist’s Perspective

  1. Debbie Walker says:

    Great article, Mary, on a topic that is always on our minds, if not on our lips,
    at our house. Thanks so much!

    • Mary Gerush says:

      Thanks for reading! My research was very educational personally, and I’m glad you connected with the post!

Back to Top ↑
  • Support our Site!

  • Let’s Connect!

  • Popular Posts & Pages

    Whether you are looking to completely give up animal products or just want to try eating vegan some of the time, we want to support you! Below, you’ll find articles answering some common questions about vegan cooking and nutrition. If you don’t see your question answered below, please get in touch with us! We are happy to investigate for you!

    Find out what's in season now, plus get plenty of recipe inspiration to help you make the most of every season's beautiful, local fare.

    I love infographics. When I came across this one about what, how, and when to plant vegetables, I thought I’d share. Keep reading after the pic for a few of my own lessons learned.

    Top Sustainable Food Jobs of the Week.

    Looking for an all vegan grocery store? Even if you’re not lucky enough to have one in your town, there are lots of online options for vegan grocery shopping.

  • Search the IM Network

  • The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by, and do not necessarily represent the views of Sustainable Enterprises Media, Inc., its owners, sponsors, affiliates, or subsidiaries.