The Metric System in the Supermarket — Part 1: A Little History

Proposed new nutritional labeling

Proposed new nutritional labeling

Last Thursday (February 27, 2014) the U.S. Food and Drug Administration announced new nutritional labeling standards for packaging in the United States. The original law, called the Nutrition Labeling and Education Act, was put in place in 1990 in an effort:

  1. To clear up consumer’s confusion about food labels
  2. To encourage consumers in making health food choices, and
  3. To encourage product innovation so that manufacturers are given an incentive to improve the quality of the food and make more healthy food choices available to consumers.
                                            Virginia Wilkening
                                            Food and Drug Administration

It was probably less effective on the last point than the first two but let’s examine a little history.

Measurement and trade

Since people have traded with one another, sellers have tried to cheat their customers to their own ends. That’s one of the reasons why throughout history there has been resistance to setting measurement standards (the metric system included). The new  regulations adjust serving sizes (mostly upward) but also highlight the nutritional information on the labels.

Serving sizes

While researching this project, my contact at National Institute of Standards and Technology recommended a book called The Thumb on the Scale or the Supermarket Shell Game by A. Q. Mowbray. With a copyright date of 1967, it relates that after World War II, consumers (quaintly referred to as “housewives” throughout the book) were getting up in arms because, as they purchased more convenience foods, they started having problems figuring out how much product to buy because the serving sizes were not standard. Each company made isolated decisions regarding what an “average” serving size constituted.

To one manufacturer, a serving of peaches might be two halves; to his competitor, it might be one half or three halves. It is like buying by the hat—and using the seller’s hat as a measure. p. 92.

In case the problem with having non-standard serving sizes for food isn’t readily apparent, let’s apply that logic to something we deal differently with today: gasoline.

The scenario goes like this: You need some more fuel and there are two gas stations across the street from each other that have determined their own “serving sizes.” Lo and behold, the price of one of the serving sizes is less expensive than the other. Is it really a better deal or just a smaller serving size? Without further investigation, there is no way for the consumer to know and that’s exactly what was going on in the grocery stores. A glance at two, say, cereal boxes next to each other might seem like the one with more serving sizes for the same price is to be a better deal. But would that impression be accurate? At the time, the answer was “No.” Enter the federal government.

While the serving sizes have been fixed by the federal government since the Fair Packaging and Labeling Act of 1966 (metric units were added to labels in 1992), there was plenty of resistance from the food industry according to the book since deception would become more difficult via that method.

And manufacturers still play games with us

Don’t worry about the food industry. They’re still finding way to take advantage of us today. You don’t have to read many issues of Consumer Reports to see an example where a reader has bought a usual item only to get home and realize the new box or bag contains less than when it was last purchased. Just because the manufacturer has adjusted the weight or volume in print (according to regulations) doesn’t mean they’re not trying to hide something. (When was the last time you saw a box emblazoned with “Now, less for the same price!”?) Yet it downsizes product contents all the time.

Let me tie in the metric system more closely: the labels will continue to be a mishmash of metric and U.S. customary measures (for new readers of the column, we don’t use Imperial units in the country, but our units are derived from them). In the example, the serving size is expressed in both customary and metric units but the nutritional content is only in metric units and thank goodness. If they were in fraction of ounces, you wouldn’t know if they were weight or volume (metric units only express mass—which relate to the gravity of the planet you’re on) or some other incomprehensible subunit. For instance:

Protein = 3 grams = 0.10582oz

If I tell you that a gram is roughly the same mass as a standard (that word again) paperclip, that’s fairly easy to imagine. Now, try to imagine a unit of 0.1 of an ounce. A bit tougher for most people I’d guess.

This post has run as long, or longer, than it should. Stay tuned. There’s more to learn.


Metric Conversion and “Rational” Sizing

I’m learning lots of new things as a result of this project and a concept I became aware of early on was “rational sizing.” I’m writing about this subject now because there’s been a lot of traffic on this idea on the U.S. Metric Association’s listserve under the name “oddball measurement.”

What it basically means is that when moving from U.S. customary units to metric ones, things might not end up with what some people call “rational” (or rounded) numbers. I was also told by a reliable source (thought I have to admit that I have not yet confirmed this) that rational sizing was one of the points of resistance by the food industry back during our last metric push in the mid 1970s.

I’ll try to explain:

If you have a traditional U.S. eight-ounce container and you want to move to the metric system, you have two options 1) retain the same packaging and “re-label” (though metric units are on most American packaging) the container as 236.588 milliliters (not sure how precise labels need to be), or 2) you resize the package to something that seems more “rational” like up to 250 mL or down to something like 230 mL. Apparently, in some people’s minds numbers that end in zeros or represent commonly used numerical breakdowns such as 25, 75 are more “rational.” I don’t personally have that bias but different minds work in different ways. (I supposed a third option would be to keep the packaging size the same and round down the milliliters it contains to a rounded amount but that doesn’t seem to be the direction most companies take.)

GlueFor example: within my reach (I’ve confessed to my laziness before) is a bottle of Elmer’s Craft Glue. Its label states that it holds “4 FL OZ (118 mL).”

My understanding (and I’ll confess to being overly dramatic here) is that 30 years ago the food industry in this country had two objections to going metric and one related to rational sizing. “Oh my God,” said the food industry, “if we go metric we’re going to have to move to rational sizing, which means we’ll have to change all of our packaging, and that will be expensive, and then nothing will fit correctly on the shelves in the stores, and we’ll have to change the size of the shelves as well. That’s an impossible thing to ask us to do.”

I consider this argument poppycock and not the popcorn kind.

When the time comes (though I don’t expect to have any actual say in the matter), just take the customary units off and let the metric units stand on their own until a redesign dictates new packaging and then make a minor adjustment in the volume if having a “rational number” is all that important (and I’m not convinced it is). Heck, I could see manufacturers use their traditional “sleight of hand” and make the packaging slightly smaller and keep the prices right where they are. This has historically been done many, many times and Consumers Reports magazine highlights these sorts of tricks on a regular basis.

Sutter_labelActually, after a quick look around, I now have in front of me a bottle of Sutter Home Champagne Vinegar and its label reads “12.7 FL. OZ. (375ml).” In this case, it’s the milliliters that are “rational” and yet I bought it even before I started my metric quest. I’m sure at the time, having a less rounded number for ounces didn’t phase me in the slightest.

So, if you hear the “rational sizing” argument thrown around in future in a move to the metric system, at least you’ll have some background on what it’s all about.

As far as I’m concerned, rational sizing is not a rational argument.


Note: The phrase “rational number” in the above context does not represent its true arithmetic meaning. For more information on that use see Be prepared that most definitions I found required an understanding of the words “integer” and “quotient.”