South Beach Diet - Glycemic Index & Glycemic Load

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06-07-2009, 12:59 PM

I came across this link while perusing the Glycemic Index of different foods.

I am not promoting this specific diet, by any means, but I am trying to stay low on the GI while on P2 of South Beach.

Thought others might find it helpful, because it's very user friendly.

06-07-2009, 01:28 PM
Thanks for sharing the link Debbie. More recent stuff I've been reading indicates that glycemic load is more reliable than glycemic index. Check out
Nutrition Data is another great website to look up all the info about just about any food (I've stumped it a couple of times).

I love looking through the lists because sometimes I find foods I hadn't thought of ;)

06-07-2009, 03:11 PM

Thanks, Cyndi. I find the first link useful, because I can all the listed items of each catagory at once, ie:cereals, but then I can go further and look at the GL.

Do you know, off hand, if there is a a rule of thumb for low, med and high GL?

06-07-2009, 03:22 PM
Cyndi, I think the Glycemic Load is much more accurate than the GI. Do you know why Dr. A doesn't approve of corn? It seems to be low on both. I really think it is a very healthy food. With all the new data on resistant starch in corn, potatoes and bananas, it makes me want to rethink eating these foods I had been avoiding. Also, what is the range for Glycemic Load? It doesn't say high or low, just the number.

06-07-2009, 06:21 PM
Glycemic load below 10 is low, 11-20 is medium, and over 20 is high.

I don't know the answer about corn. I do know that my diabetic partner reacts more to corn and white potatoes than some other foods, but not bananas :shrug:

I think part of the problem with corn is that it is in everything, usually in a highly processed form. I wonder how much Dr. A researched the difference between corn on the cob and corn as filler. I do eat corn on the cob when it's local, but don't eat any corn derivatives. For me white potatoes were part of the problem so I need to stay away from them. Never have trouble with bananas though

Two more sites, 1 with info and 1 with a long list:

06-24-2009, 12:35 PM
With the talk about this going on in the Watermelon thread (, I thought I'd post some info I found about Glycemic Load (GL) to help de-mystify it a bit for all of us.

This is from Diabetes Self-Management (

One other “downside” of the GI [Glycemic Index] is that fact that the ranking system doesn’t take into account the amount of food one eats. Here’s an example. People are often surprised to see that carrots, much like watermelon, have a high GI. The inclination is to stop eating carrots. But think back to your nutrition class in school—carrots are good for you! Besides being low in calories, high in fiber, and rich in beta-carotene, a half-cup of carrots has just 8 grams of carbohydrate. So why does it have a high GI?

The GI was originally developed by researchers for research purposes, and it was calculated from servings of food that contained 50 grams of carbohydrate. [bolding mine] In the case of carrots, you’d have to eat about 1 1/2 pounds to get that much carbohydrate! Would you eat that many carrots at one time? Probably not. The GI doesn’t take into account realistic serving sizes. However, the glycemic load does.

Glycemic load (GL) is the amount of carbohydrate in a food multiplied by that food’s GI. The GL is also a ranking of how foods affect blood glucose levels, but unlike GI, the GL takes serving size into account. Like GI, the lower the GL, the lower the spike in blood glucose levels. Low-GL foods have a value of 10 or less; moderate-GL foods have a value of 11-19; and high-GL foods have a value of 20 or more.

Back to the carrots, then. Carrots have a GI of 71. If we multiply the 8 grams of carb in a half cup by .71, we get a GL value of roughly 6. Therefore, carrots are a low-GL food. This means that, unless you truly are going to eat a pound and a half at a time, carrots don’t have a big impact on blood glucose levels.

I believe Dr. A does take Glycemic Load (GL) into account--that's why we're allowed to have medium-sized bananas, but not large ones. In fact, it's why he changed the list to allow for bananas in the first place. Their GI is high, but the GL of a medium one is okay. However, I'm not sure what the thought is about corn. I agree with Cyndi, that it might be because corn is in so many things. We are allowed air-popped popcorn in P2, though, so he obviously thought about it at some point. Is anyone on a site where they can submit a question to Dr. A about it?

Although GL is highly recommended as a way to manage blood sugar for diabetics, there are some concerns about whether using low GL foods can help with weight loss:

Das et al. conducted a study ( 36 healthy, overweight adults, using a randomised test to measure the efficacy of two diets, one with a high glycemic load and one with a low GL. The study concluded that there is no statistically significant difference between the outcome of the two diets. However, this might simply be due to the small sample size (n=36). In the study, the low GL diet did provide the most weight loss on average, but not enough to clear the bar of "statistical significance". See Das et al. (2007). "Long-term effects of 2 energy-restricted diets differing in glycemic load on dietary adherence, body composition, and metabolism in CALERIE: a 1-y randomized controlled trial" American Journal of Clinical Nutrition (, Vol. 85, No. 4, 1023-1030

This chart ( you some really good information in comparing GI and GL. The first number in the parentheses is the GL and the second is the GI. The article that accompanies the chart can be found here (

There's a lot to think about with all this...I think sticking to the SBD guidelines, overall, is the best way to start. Then, if you want to try other things to see how your body reacts, using the GL lists can really help you pick ones that are less likely to affect you.

The one thing to remember is that, unlike the GI, the GL is based on portion/serving size. So if you eat more than the serving size, you can assume that the GL of what you've eaten will be different. Therefore, when trying these things, you need to stick to serving size.

06-24-2009, 07:33 PM
Is anyone on a site where they can submit a question to Dr. A about it? (corn)

I went through the "Ask Dr. A" and "Ask the Nutritionist" boards over on the official SBD site. Nothing from Dr. A but found this on the Nutritionist boards:

SBD Corn Questions

Q: Why canít I eat corn on the cob?

A: It is understandable your confusion about why corn is not listed as a phase 2 food to enjoy. Not all vegetables are digested and affect blood sugar the same. Some that contain more starch and are digested more readily. As a result they cause a more rapid rise in blood glucose levels. Corn has a Glycemic Index and a Glycemic Load that would put it into early phase 3. The average GI is 54 (using glucose as a reference).
However, you can enjoy some regular corn occasionally as a starch once per week during phase 2 if you wish.
I hope this information helps.
Best Wishes,
Ellen, South Beach Diet Nutritionist

Q: In phase 2 you cannot have corn but yet you can have popcorn? This makes no sense to me!

A: Popcorn is allowed in limited amounts in Phase 2. It is a special corn that results in a lower GI. It is a lower moisture containing corn that inhibits starch gelatinization. Also, you're really only eating a small amount of corn when you have a regular serving of popcorn.
Rachel--SBD Nutritionist

I'm still confused! :dizzy: If someone could come up with a good question about corn I would be happy to post it to Dr. A. :)

06-24-2009, 08:24 PM
I think that most good commerical diets have to oversimplify to reach the most people. It's why I don't think "tweaking" is such a horrible thing, if you're really being honest with yourself about the results of your experiments. But can you imagine how complicated any plan would be, that tried to list and quantify all the foods that some people may have more of a problems with than others, or a food (like corn/popcorn) or white potatoes that may be fine in some forms or presentations, but not in others, or in some quantities/amounts/frequencies, especially in a plan that is saying you don't have to worry about such things.

How can any plan be written to be equally applicable to a person with 200 lbs to lose as the person who has 7? I think it's fairly safe to say that beets, carrots, fresh sweetcorn and watermelon are far less of a problem for me now, than they might be when I have only 15 lbs left to lose. That gets lost in any book trying to speak equally to me and the person with only a few pounds to lose.

I think people often get hung up on details, because there's a cultural expectation that any diet must be followed to minute detail or "poof" it won't work, breaking the magic spell of the diet. "If I eat a banana that's closer to large than medium, I might as well be eating brownies."

It's a slippery slope if you allow it to be (and it's easy to allow it to be). For many it's easier to follow "rules" than "guidelines." Other people find strict rules too constraining and frustrating, so most diet plans to be commercially successful have to be offer a little of both. Guidelines that can be interpreted as strict rules, for those who need them.

How far can you deviate and still be following the plan closely enough to call yourself a follower of the plan? Why does that seem to be a more important concern than whether what you are doing is working for you?

To avoid confusion, most people just keep quiet about their tweaking or face sometimes harsh criticism. People who are losing great and eating x if they admit to it are told "you're not following South Beach if you're eating x (watermelon/sweet corn/ a large banana), so don't say that you are." I kind of doubt that Dr. Agatson would take that position, and on the other hand, I do understand not wanting to confuse new followers to SB who say "I thought we couldn't have x (watermelon/sweet corn/ a large banana)?

It can be a polarizing subject and I don't think it has to be, unfortunately though that's human nature. If you're making a small exception to the plan, and succeeding, it can be easier to keep your mouth shut, than discuss it. Not better, but definitely easier.

I don't think that's what Dr. A had in mind at all. I've read several of the South Beach books, and none were written in "follow these lists or die," mode. Even in the earliest stage, foods are listed with wording to the effect "avoid or eat infrequently," not "never eat this, for if you do you are banished for eternity from the magical land of South Beach."

06-24-2009, 08:44 PM
I think this thread is really, really valuable because if one DOESN'T question "the rules" and just blindly follows, are they not placing the responsibility for their choices in the hands of others???
I was on a Very Low Calorie doctor-supervised diet, and when I started to question WHY I was getting only 425 calories a day despite the advertised 900 calories a day, and WHY I could eat some foods and not others, the "experts" had no answers.
One HAS to take responsibility, and the question about corn IS valid.

As for popcorn, even though it is a different variety of corn, it still has sugar. Perhaps it has to do with the amount you get in a cup of popped corn vs the amount you get in a cup of corn taken off the cob.

In any event, keep on asking the questions. You may be surprised at what you discover, about the question itself and about how you react to the answers you get and thus learn about yourself!


06-26-2009, 12:57 PM
Cyndi - thanks for reminding me about Nutrition Data, I love that site but my bookmark got wiped out when computer crashed and I forgot about it.

06-29-2009, 01:39 PM
It's a slippery slope if you allow it to be (and it's easy to allow it to be). For many it's easier to follow "rules" than "guidelines." Other people find strict rules too constraining and frustrating, so most diet plans to be commercially successful have to be offer a little of both. Guidelines that can be interpreted as strict rules, for those who need them.

Kaplods, I think that's the key. SBD is more of a guidelines diet (which is why I think it's so successful as a way of eating for life, rather than a "diet"), and that means you need to be informed, read the book, and be up-to-date on new things we learn about eating.d

Mizski, thanks for checking on the site! Hopefully someone here can explain the corn issue in a good question that you can post. What things still confuse you after reading those answers? That might help in forming a question...

06-29-2009, 09:00 PM
I couldn't have said it better