Is it how much you’re expected to eat? How much you should eat? Pardon me, but if I want to eat an entire bag of potato chips, that’s exactly what I’m going to do.

I say this as the guy who helps create nutrition facts panels for food products for a living. I have read, reread, proof read, and colored red hundreds of these little tables in my time, and believe it or not, people aren’t lining up at parties to hear my thrilling stories.

I know!

Right now you’re thinking, “But Austin, I remember back in 2008 the FDA called 2,584 adults from the US to ask them questions about their diet. And 24% of the respondents said they had no idea if serving sizes were determined by government rules or by manufacturers.”

Your oddly specific observation would be correct, and I should have at least ¼ of the room hovering around me in rapt attention, waiting for me to clarify this confusing point. Time has shown however that everyone is clearly too intimidated to approach and ask the simple questions, even when I’m subtly firing off labeling trivia from the empty cracker box carelessly left by the cheese platter, or establishing my mastery of the dance floor.

Fact: Every party has a dance floor, here’s the label. Well let’s clear this up right now while I’ve got you at home/work/somewhere, on your computer/phone/tablet (scary that I know where you are, isn’t it?). Who determines serving sizes, manufacturers or the government?

Answer: The government!…ish.

Well that was unsatisfying, but it’s the most accurate answer I can give. Essentially what happens is that our government, via the FDA and FSIS (Food Safety Inspection Service), determine how serving sizes are to be calculated and presented, but also leave manufacturers options in specific situations.

So how are serving sizes determined?

Step 1, what are you eating?

he first step companies need to take when determining serving size is to determine what type of product they are selling. Back in 1993 when they had to decide all of this stuff, FDA determined that they could use data collected in the NHANES dietary surveys conducted in 1978 and 1988 to set these standards. These were nationwide surveys that collected all sorts of data, including nutritional intake and food frequency data. With this information, FDA created “Reference Amounts Customarily Consumed,” or RACC, for different categories of food.

The first step is easy, find the category that a food falls into, and look up the RACC used to determine the serving size in 21 CFR 101.12 (for non-meat items). For example, if I was making mashed potatoes, my category would be “Potatoes and Sweet Potatoes/Yams: Mashed, candied, stuffed, or with sauce” and my RACC would be 140 grams.

Step 2, how can someone measure it out?

Here’s where the variation begins! You might just want to use that 140 grams we saw above; however, not everyone has a scale in their kitchen, and let’s see you try to guess how much mashed potato makes up 140 grams. Can you think of the last time you weighed your food, much less with metric weights (provided you live in the U.S.)?

So at this juncture, the government instructs manufacturers to determine what the closest “common household measurement” to one RACC of your product is. So if we take 140g of our potatoes and see that that’s about 2/3 of a cup, our serving size becomes 2/3 of a cup!

>THIS IS IMPORTANT<

Imagine we made a new, super fluffy mashed potato with more butter, and 140 grams of these potatoes actually wind up closer to ¾ of a cup. This means that even though both potato products were based on a RACC of 140g, they might have two completely different serving sizes, and the manufacturer arrived at each using the same government reference amount!

So there you have it, two serving sizes created based on a government standard, but completely different once observed on the store shelf. How could there be even more variation?

Single Serving

Ah, right. For many products, if the entire container contains less or near 200% of the RACC amount, then there are different rules to play by. In most cases, the product will be considered a single serving, but in others, manufacturers have the choice to label them as one or two servings. This is why you see different types of labeling in small containers such as ice cream, muffins, soda, and other “single serving” containers that appear significantly larger than the usual RACC amount.

As eaten, not as sold

Ah, and this is critical. When you ask someone how much cake they eat, they typically don’t respond with, “about 1/3 of a box of cake mix”. RACC values are based on products as they are consumed. However, serving sizes are based on products as they are sold. The reasoning? Because it would be bizarre to buy a bag of flour and see “two slices of bread” for a serving size. This makes more sense for some products than others, but ultimately serving sizes for products that require further preparation are the amount of packaged product it takes to make about 1 RACC of product as eaten. And remember, this must be rounded off at a common household measure!

Final thoughts

As we realize that our beloved nutrition facts panel is now old enough to drink (enforcement began in ’94), we look back and start to wonder if that data from the 70’s and 80’s used to determine RACC values still holds water. I can’t think of anyone who eats ½ cup of ice cream in a sitting, nor leaves the potato chip bag untouched after their first 10-20 chips.

But how about we think about RACC values in a different way. These values were never intended to be an expectation, but simply a way to bring nutrition information into context using consumer data. The thousands of calories in a 20 lb. bag of rice don’t have a lot of context when I eat it one bowl at a time, but that’s also not to say that I’ll never eat an obscene amount of rice in one sitting just because I’m starving.

Instead think of it this way, if these values are simply references to what we customarily consume at a time, we’ve got a great tool on our hands. I wouldn’t expect you to eat only ½ cup of ice cream, but have you noticed that many ice cream scoops happen to portion about ½ cup of ice cream at a time? And while I’ve been known to turn a bag of kettle fried chips into a meal, I still eat them one handful at a time, which just so happens to contain approximately 10-15 chips.

If only some sort of reference was available so that I could tell about how many calories I ate with each handful…

To learn more about how serving sizes are determined for all food products, check out the labeling and nutrition documents on the FDA website, this PowerPoint provided by the FSIS, or the Guide to Federal Food Labeling Requirements for Meat, Poultry, and Egg Products. Check out what consumer opinions of labels are looking like since 2008 in the FDA’s consumer research.

Choinière C. & Lando A. (2008). 2008 Health and Diet Survey, DOI:

Conrad J. Choinière, & Amy Lando (2008). 2008 Health and Diet Survey FDA Consumer Behavior Research Foos Safety Surveys (FSS)