The Hard Thing About Teaching Nutrition

The hard thing about teaching nutrition to college students is that, as far as eating healthy is concerned, they’ve heard it all before. In fact, Michael Pollen’s phrase, “Eat food. Not too much. Mostly plants.”– is about the best 3-second nutrition message around. I find myself wanting to repeat this phrase to my students and dismiss class for the semester.

I don’t, though, because “Not too much” is the dirty bomb of nutrition. Whenever I ask my class if they have eaten a Hershey’s Chocolate Kiss in their lifetime, I already know the answer. It’s always 100% hands raised.

Hershey’s has our number. They exploit our psychology of eating and here’s how. They know people will eat more of one kind of food if we perceive that there is variety (even if there is no real taste difference in that variety). Case in point, in a 2004 study people offered M&Ms in 10 colors ate 43% more than those offered the same number of M&Ms in seven colors. That is the difference between 91 and 63 candies over an hour. Same flavor, different color, more eating. Hershey’s knows this and in the sixties they started adding color to the silver foil wrapper. Red and green for Christmas, pastel colors for Easter, orange and brown for autumn and what did we do? We ate more Kisses. Perception is everything and can overwhelm judgment in the sneakiest of ways.

I find this information thrilling. I love learning how I’m influenced right under my own awareness. In a 4-week study from 2006, researchers studied 40 adult secretaries to see if visibility influenced chocolate consumption. When 30 Hershey’s Kisses were placed on the desk of secretaries in a clear jar the secretaries consumed the Kisses 46% more quickly than those in opaque jars. Walk through the grocery store and check out the designer bags, glass jars and tubes of chocolate everywhere.

Manufacturers use the science behind consumer behavior and nutrition to influence consumption all the time. Scientists know that how much we eat has less to do with hunger and satisfaction and is easily influenced by 1) sensory cues (how your senses react), 2) emotional cues (how you feel), and 3) normative cues (how you believe you are supposed to eat). For example, we really love texture in our food, like chocolate chips in our cookies and pasta of different shapes instead of just one continuous type. When offered variety and texture we will eat 15% more every time. If we add our emotions and peer behavior in as influences on eating, you can see why we have so much difficulty eating too much.

Studying this lead me to a really fascinating discovery about how much more we pour of any beverage depending on the glass size and shape we pour into, or the container we pour from. Researchers found that individuals will pour 88% more juice or soda with short, wide glasses than with tall, narrow glasses even if the volume of the glasses are the same. If asked to pour from a large container to a small container they over estimate an appropriate serving size every time. Even when shown that larger sized packages cause people to underestimate consumption by at least 20%, most people maintain that they are unaffected by such things.

You might think so what? What’s a few extra ounces? What’s 10 more M&M’s or Chocolate Kisses between friends? It’s not your friends I’m worried about, it’s what’s coming between me and my skinny jeans. One chocolate Kiss is 22 calories, which means 5 more Kisses, is 110 calories. I would have to run the length of a football field (100 yards) 36 times to burn off those Kisses.[Tweet “One chocolate Kiss is 22 calories, which means 5 more Kisses, is 110 calories. I would have to run the length of a football field (100 yards) 36 times to burn off those Kisses.”]

Because of this research I have changed my behavior and my teaching. I don’t have food out on counters, in dishes, or even at the dinner table. I keep food covered, on the stove or in cupboards and that helps a lot with the visibility issue. I eat with small plates, don’t keep candy at my desk, and try very hard not to let myself get hungry. I keep in mind that a lot of variety can mean both more taste but also more calories and use the science to combat marketing.

And what about my teaching? I’ve added a large behavioral science portion to my nutrition classes and we do a lot of simulations to show how my students react the same way as the rest of the world, even when they don’t want to believe it.

Recently, when a colleague asked me to help him eat more carefully, I didn’t talk about fruits and vegetables as much as I talked about what influences us in a way he hadn’t thought of before. After that conversation I dumped the candy bowl on his desk into a drawer, told him to stay away from buffets and start using measuring cups. That’s what I do. I’m an exercise physiologist, an exercise psychologist and a former triathlete. You’d think that I’d be too smart for packaging to pull one over on me. But, even given how much I know I can still be influenced by a candy dish or a clear bag of chocolate or a pretty pink cupcake. [Tweet “We are mortal beings where packaging is concerned even the mightiest of us fall. *wipes frosting from mouth.”]

This was originally published here at The Last Word On Nothing


  1. […] simplify our lives. No, I’m not baking cookies for a second-grade soccer team who doesn’t need bakery after a game. No, I’m not going to fill a volunteer spot that already has too many volunteers […]

  2. Dear Darling, - Ann Garvin on March 19, 2021 at 12:35 am

    […] P.S.  This little ditty is about what I want people to know about food. […]

Leave a Comment