Terminology in nutrition

December 18, 2006 12:10 PM

I use Fitday (the Windows program downloadable from Fitday.com) and I don't understand the difference between "oz" and "oz, raw, yields" in things like "Onion, mature, raw" and "Cabbage, red, raw". The "oz, raw, yields" includes "raw" a second time (redundant, right?) and what's with the "yields" as opposed to just "oz"? Anyone know? (Fitday is not the only one with the usage, I believe.)
posted by LeisureGuy to Health & Fitness (10 answers total)

Is the NI provided the same? If so, I think they are just being redundant. FitDay seems to have combined several databases of nutritional information, so I think there is some repetition in there.
posted by tastybrains at 12:16 PM on December 18, 2006

I'm not entirely sure, but this is how I have understood it. I think it has something to do with the fact that when you cook stuff, some things cook down. So 1 oz of onion, when cooked, may yield a different amount. Since you don't usually measure your food after you have cooked it, "1oz raw, yields" represents the amount of cooked onion that came from your original 1 oz.
posted by arcticwoman at 12:16 PM on December 18, 2006

Yes. I read "yields" as a verb meaning "produces" or "results in"
posted by winston at 12:30 PM on December 18, 2006

Ihave a cook book that, most unhelpfully, will call for things like 10 ounces of cheese (283g) grated to yeild 12 fl oz (355ml) but forget to mention which kind of oz it's referring to at the time.
posted by mce at 12:53 PM on December 18, 2006

Response by poster: Interesting: I took tastybrain's suggestion and tried "10 oz" and "10 oz, raw, yields" for raw onion. The former produced 108 calories and the latter 99 calories. Not much difference.

So far as cooking down, both measurements are of raw onions, I had assumed. But maybe the oz, raw, yields assumes that I am measuring after cooking? But then why would that give me fewer calories? Weird.
posted by LeisureGuy at 1:03 PM on December 18, 2006

It's likely the weight after cooking. For example, 1 ounce of frozen broccoli yields less once you cook it and drain the water off.

Also, keep in mind many of the nutrition values on FitDay were taken from users, at least in the beginning. That's why you find several listings of the same item, just worded differently. Errors are possible. I always supplement my FitDay totals with my own nutritional figures based on package listings, calorie-count.com, and other places.
posted by smashingstars at 1:09 PM on December 18, 2006

Best answer: I would say it was the weight of actual edible food. For example, you don't eat the skin or maybe outer layer of the onion. So an onion that weighs an ounce yields slightly less onion that you'd actually eat, once it was peeled and chopped and had the weird green bit in the middle taken out. (That's why both measurements would be 'raw')
posted by slightlybewildered at 1:16 PM on December 18, 2006

Fitday (and many other online calorie databases) uses the USDA's National Nutrient Database for Standard Reference and the derivative Food and Nutrient Database for Dietary Studies for many of their calorie/nutrient values. You can find documentation for both of these, with more info about the food descriptions, which are pulled directly from the USDA database, here and here. I would recommend e-mailing the USDA though, as that documentation doesn't really go into a lot of detail of what they mean when they say "yields", etc.
posted by longdaysjourney at 3:08 PM on December 18, 2006

Response by poster: Slightlybewildered answer makes a lot of sense: if you just weigh an onion at 10 oz and then trim it, you're going to get less onion than if you trim it before weighing. So the "oz" would be the weight of actual edible onion and the "oz, raw, yields" would be the weight before trimming---so that the calories for this measurement is less.
posted by LeisureGuy at 4:01 PM on December 18, 2006

Response by poster: But maybe it is the yield after cooking. Look here.
posted by LeisureGuy at 4:04 PM on December 18, 2006