Your Supermarket is like a Volcano

by aturne on March 1, 2013


Last year my classmates and I were instructed to brainstorm messages that would help people eat healthier. My personal favorite was “your supermarket is like a volcano.” Almost a year later, it stuck. Every time I’m at the supermarket, the comparison to a volcano cues me to stick to the outskirts of the store. Fruits and vegetables, I’m safe. Closer to the middle that’s filled with chips and cookies, not so much.

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Why is the middle of the supermarket so much of a danger?

The middle of the supermarket, for the most part, tends to host a large amount of processed foods. Next time you’re walking up and down the aisles take a look. We have tons of low fat, low sodium, low carb, low calorie options. For every regular food, there seems to be a diet one to match it. So we’re covered right? Maybe not. New research suggests that how food is labeled presents multiple problems for consumers. 

Health Halos on the Rise

Health halos occur when a consumer sees only one positive element of a food and neglects the other potentially unhealthy elements. Even the most nutritiously savvy person can be duped into overestimating the value of a food for a single health benefit i.e. low fat. For example, Kellogg’s Raisin Bran cereal shows they are a good source of fiber and made with whole grain. Even the word bran sounds healthy. But a single serving has 250mg of sodium. That’s almost 10% of your daily value.

Another consequence of health halos is that it leads you to eat more. You may not eat a single serving of raisin bran (1 cup) instead you eye ball it and end up eating almost double. Researchers demonstrated the effect of health halos in the lab. When participants were told to serve themselves either regular but new color M&Ms or new low fat M&Ms participants ate almost 30% more. Overweight participants tended to eat even more of the low fat M&Ms, increasing their consumption by 47%. Plus these participants assumed they were eating less, even though they were eating more.

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A raisin bran health halo may also influence how you feel about how much cereal you eat. Let’s say you do eat a serving and have almost two cups of cereal. What would you estimate as the calorie content for what you ate? The same researchers found that when offered low fat granola or M&Ms and asked participants how about how many calories they thought were in each, participants believed low fat foods to be lower in calories. On average about 260 calories less.

Researchers also found a trend towards overeating with eating out. They found that eating one healthy thing  made people feel more comfortable adding an unhealthy food to their meal. For example, at Panera you decide to have a salad for lunch and  because you eat healthy you reward yourself with a cookie. Yum! This behavior can actually make you eat more calories than you would with a traditional meal. This isn’t everyone, but it’s a trap that many of us can fall into.

If food labels are deceptive, what can we do?

Healthy eating isn’t something that happens overnight. We lead busy lives and often convenience wins out over spending time preparing meals. 

Potential Policy Changes:

  • More relevant nutrition claims
  • Standardize relevant nutrition claims
  • Change the definition of serving sizes

What you can do:

  • Check the label, does the front match the back?
  • Plan ahead with a food shopping list
  • Read the ingredients, can you pronounce all of them?

Sure this kind of approach to grocery shopping takes work, time and effort. But it doesn’t have to be applied to everything you buy. Maybe you could try taking a closer look at one thing per trip. Or if all else fails, you could just remember my grocery shopping mantra “your supermarket is like a volcano.”

What are some of your healthy grocery shopping tips?


1. Provencher V, Polivy J, Herman PC. 2009. Perceived healthiness of food. If it’s healthy, you can eat more! Appetite. 52(2):340-344.,

2. Wansink B & Chandon P. 2006. Can “Low-Fat” Nutrition Labels Lead to Obesity? Journal of Marketing Research. 43(4): 605-617.

3. Andrews JC, Burton S, Kees J. 2011. Is simpler always better? Consumer evaluations of front-of-package nutrition symbols. Journal of Public Policy & Marketing. 30(2): 175-190. 10.1509/jppm.30.2.175

4. Chandon P & Wansink B. 2012. Does food marketing need to make us fat? A review and solutions. Nutrition Reviews. 70(10)