T Nation

Which Yam is the Scam?


#1

Yams, sweet potatoes? I can't distinguish the two. Yams have come highly reccomended as a good carb source but how exactly can u distinguish them from their high glycemic twins the sweet potatoe?

Anyone know which is the red/ maroon coloured variety?


#2

A yam and sweet potato are the same as far as I know, only the word yams is sometimes used to mean a sweet dish sometimes covered with marshmellows. Or maybe my family is the only one who used to do that for Christmas dinner??

Anyway, as long as you don't buy the canned kind in syrup, you're fine. Just get them in the veggie area of the grocery store. I love these things because you don't have to put anything on them and they taste great.


#3

davo2,

"A yam and sweet potato are the same as far as I know, only the word yams is sometimes used to mean a sweet dish sometimes covered with marshmellows."

Yams and sweet potatoes are WAY different GI-wise. Yams are quite low while sweet potatoes are very high. That dish is called candied yams in my neck of the woods :slight_smile:

But as to the difference, I've never looked for myself, but I've been told yams are a dark orange (well, I know this from eating them) and that sweet potatoes are lighter in color...almost yellowish on the inside. I wonder if a sweet potatoes looks just like a white potato on the outside, because yams are longer and thinner than normal potatoes.

Also, don't they label them when you buy them? :wink:


#4

I just found this

http://www.brightharvest.com/index_files/page0005.htm

and this

http://www.layams.com/


#5

http://www.wholehealthmd.com/refshelf/foods_view/0,1523,40,00.html

"There are two basic types of sweet potato: Moist (orange-fleshed) and dry (yellow-fleshed). The sweeter orange-fleshed sweet potato varieties dominate the U.S. market, but some people prefer the starchier yellow-fleshed types. The moist-fleshed potatoes are often called "yams," but this is a misnomer: The true yam (botanical family Dioscoreaceae) is a large (up to 100 pounds) root vegetable grown in Africa and Asia and rarely seen in the western world. However, common usage has made the term "yams" acceptable when referring to sweet potatoes."


#6

Here's a site with a picture of each.

http://www.foodsubs.com/Sweetpotatoes.html


#7

Hahaha, all that makes things more confusing if you ask me.

Ok, if you look at a GI chart and it lists "yams", which one are they talking about? Are they talking about the moist-fleshed orange sweet potato (what Americans call yams, supposedly) or what the rest of the world calls yams (the tubers or whatever they called them)?


#8

Morg wrote:
Yams and sweet potatoes are WAY different GI-wise. Yams are quite low while sweet potatoes are very high. That dish is called candied yams in my neck of the woods :slight_smile:


Uh no. Yams and sweet potatos are actually very simlar GIs. They are both in the moderate range (approx. 50). This is one GI reference that shows the similarities: http://www.sportfit.com/tips/nutrition/glycemic_index.html. I personally eat both. Obviously you add ingredients to either a yam or a sweet potato it will change the GI.


#9

randman,

Well, I'm looking at a different chart and it says differently. Also, where you get them from matters a lot.

For example, Australian sweet potatoes had a GI of 44, which is fairly low, but New Zealand sweet potatoes had a GI of about 78, which is quite high. The average given for all the sweet potatoes is 66, which falls under the "moderate" category, but I consider that to be fiarly high.

However, "yams" from New Zealand ranged from 25-35, which is pretty darn low.

BUT, the thing I'm now confused about is what they are calling a yam. Is a "yam" a dark orange moist sweet potato?


#10

I got this from http://members.lycos.co.uk/ramendosa/gilists.htm
Numbers are: GI, serving size (g), GL

Sweet potato, mean of five studies 61+/-7 150 17
Yam, mean of three studies 37+/-8 150 13


#11

tme nailed it on the head. Although it's not technically a yam, in the US the dark orange fleshy version is called a "yam". I do admit I've seen GIs differ from different sources regarding the same food. Typically I get the US "yam" anyway becuase that is usually the only thing available in the supermarket. Sometimes they have the lighter color version "sweet potato". To be honest with you I consider the variation of 20 - 30 GI minutia between the two since I am typically eating my yam or sweet potato with a protein and a little bit of fat which will lower the GI of the meal overall anyway. So yes, the Yam probably is a little lower in general but if you throw in some sweet potatos into your diet you won't blow up like a blowfish.