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Diabetes Diet

The Glycemic Index Still Matters for Diabetes

The glycemic index is about foods that are high in carbohydrates, and the easiest way to manage our diabetes is a very low-carb diet. But low-carbing is basically taking the glycemic index one step further.

A low-carb diet isn’t a no-carb diet. In fact, the glycemic index is as important for those of us who eat 50 or fewer grams of carbohydrates a day as for people who use insulin or pills.


At the end of 2007 I switched from relying on pills and the glycemic index when I decided that a very low-carb diet was safer than using medicine, which always has side effects. Before then, my first book was about the glycemic index. I co-authored What Makes My Blood Glucose Go Up…and Down? together with the world’s top glycemic index scientist, Professor Jennie Brand Miller of Australia’s University of Sydney, and her associate Kaye Foster Powell.

Starting in 1996 I had worked with Dr. Brand Miller, when I wrote the first article in the North American lay press about the glycemic index. My article in the August 1996 issue of Diabetes Interview magazine reviewed her first book, The GI Factor, which she had published in Australia and New Zealand. Later, I introduced her to the publisher of Avalon Publishing Group, which brought out a best-selling series of her books about the glycemic index in North America, including the one that I co-authored with her.

In my 20-year journey with diabetes I tested many diets, including one that was very high carb, The McDougall Plan. While I decisively turned my back on that one, I know that the glycemic index makes scientific sense. I keep it in mind when I choose which carbohydrates to eat.

For example, one of the reasons why I eat blueberries instead of bananas is that blueberries are lower glycemic. You can find an extensive list of those foods that scientists have tested on my website at “Revised International Table of Glycemic Index (GI) and Glycemic Load (GL) Values — 2008.”

But now my concern is that the initial enthusiasm for the glycemic index has waned. Ten or 15 years ago it was the hottest topic on my website, mendosa.com. Now, I rarely get any questions about it.

Part of the problem may be confusion as to whether to pay attention to the glycemic index or the glycemic load of foods.

The glycemic index is a numerical system of measuring how much of a rise in circulating blood sugar a carbohydrate triggers — the higher the number the greater the blood sugar response. So a low GI food will cause a small rise, while a high GI food will trigger a dramatic spike. Pure glucose, the sugar that causes the greatest spike in our blood, is set at 100 and is the basic of the index. We consider a GI of 70 or more to be high, a GI of 56 to 69 to be medium, and a GI of 55 or less to be low.

The glycemic load is a newer way to assess the impact of carbohydrate consumption. It takes the glycemic index into account, but gives a fuller picture than does glycemic index alone. A GI value tells you only how rapidly a particular carbohydrate turns into sugar. It doesn’t tell you how much of that carbohydrate is in a serving of a particular food. You need to know both things to understand a food’s effect on blood sugar.

The carbohydrate in watermelon, for example, has a high GI. But there isn’t a lot of it, so watermelon’s glycemic load is relatively low.

A GL of 20 or more is high, a GL of 11 to 19 inclusive is medium, and a GL of 10 or less is low. Still, foods that have a low GL almost always have a low GI. Foods with an intermediate or high GL range from very low to very high GI.

The major problem with the GL is that it’s based on a serving size, and a serving size is arbitrary. That’s a big reason why, like most people, I pay attention to the GI much more than I do to the GL.

Perhaps the biggest problem for most people with both the GI and GL is that it seems complicated. In large part that’s because it has to include so many foods that people around the world eat.

For simplicity I put together a much shorter webpage about “The Glycemic Values of Common American Foods.” I’m hoping that many more people who have diabetes can use this table to help manage their blood sugar whether or not they follow a very low-carb diet.

This article is based on an earlier version of my article published by HealthCentral.

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  • vepa A Murari at

    Dear David,
    I have noted your ability to make do with no medication, and you are limiting carbs to 50.
    I am copying a mail I sent a Scientist friend in this blog, based on his comment on my 6 months expt. I came to know him three months after I had started the diet from your site. He has written a book Diet and Lifestyle in the 21st Century to educate people the GI and GL concepts, and several other medical facts many people know little about. And how people can make concentrated extracts at home for many common health problems.

    He suggested I calculate the GL /GI of some of the recent meals where Cals and Carbs are in the extremes. If that explains why the Diab medication worked as well as it did.
    The last few days my diet has been all over on carbs, as in the msg below, but the sugar control is still very good. (with the 2 tabs/day).
    I have referred to a calculation sheet he sent me on the issue of 14gms Carbohydrates (not 2.5 gms I mentioned wrongly earlier) creating Chorestorol and Triglycerides.. Which can upset the Lipid Profile. Possibly the reason, when on very low carbs, such reactions do not happen., and Hb1Ac stays good.. Because the first priority of Carbs is to provide energy to the body, and these reactions take place when Carbs are in excess after that.

    However, I see it is going to be difficult for an Indian vegetarian , to go down to your levels of carbs . And if that is also the reason you can manage Diabetes without medicines. I am now very comfortable on Diab control, with such a wide variation of Cals or carbs – Feel Normal, except with medication.

    If the best I can manage on Carbs is 34% on 1400 Cals, when home cooked items are included, it means 116 Carbs. To stick to a strict 60 Carbs, I may have to manage with Biscuit meals. Or stay away from many home cooked items, which upsets my wife. I am trying to make a weekly plan, so that she does not get too much done I cannot take to stay within limits.
    I am wondering, whether I will be able to eliminate medication, with either of the two methods. Or a very strict carbs control is required. Or just remain satisfied that sugars are under control. And wait patiently.
    But I added the message below, because I thought the Chemical Reaction part may interest others, and seems to theoretically justify the faith to remain LC, and the fallacy of blaming Eggs, instead of discouraging high Carb consumption.

    Dear Dr Kane,
    I plan to include this as my comment in this blog. Thank you for clarifying this morning telecom that I should calculate the GI andGL load of the large varying diets of last few days, to understand if it explains the absolutely anxiety free sugar control I am experiencing with the new DPP-4 mechanism Janumet. With a wide variation of diet Carbs:
    Cals 1000 to 1900. Carb% 25-65, single meal 10 to 60g carb ,or total daily 60 to 190g carbs.
    In A way I have accidentally stumbled on this study attempting LC HF diet, during the last few unsettled days with home cooked items added, when so much carbs variation has occurred.

    You also made the comment, that in India even holding 40:30:30 will be difficult and carbs %are more, qty people eat more than what I have recorded, GI not controlled. Hence Diab not easily controlled. Fortunately I have achieved control over a wide range.

    Your calculations which shows 14 gms of Carbohydrate INTAKE excess can produce (if in excess. of energy needs), Cholestorol equivalent to 3 eggs, and 3.5 gms Triglycerides, was to point out the fallacy of blaming eggs consumption. And the Indian problem in Diab, different from the West.viz high tryglycerides. Indians being heavy Carbs consumers.
    Well I may have been out of this archetype last 10 years, and certainly last 6 months.

    Your calculations perhaps maybe the reason low. Carbs diet, by very reason of adoption, leads to Lipid Profile improvement , as claimed by advocates of LCHF Diets. As the extra energy comes from Fat and Protein. Hence less Triglicterides and LDLC gets produced. Why I want to persist with LCHF

    In the last 6 months experimentation with LCHF, 4 months continuing old style of 10 years 2/3 Tab combination, next 1 month Vobose, and after that Janumet.
    The last provides very comfortable sugar control and digestion. Possibly a tendency for sore throat, as side effect, nothing serious.

    If Iwant to stick to strict 60 gms carbs, I can live off Cream Cracker biscuits, 5g and 30 cals per biscuit, for 3 meals, and Solid snack the rest with fats and proteins in my pocket. And fruitsraw vegetables. No cooking involved. Coconut oil with Coffee Tea, or Protein supplement drink taken 3 times a day, or Butter, Ghee with Biscuits,

    But including what my wife prepares out of love and affection, has to be chosen with extreme care not to give offence, because they throw all carbs and cals target out of the window. I now plan on the Smartphone, and tell her how much I can accommodate next day. Tried first time last night for today, it has resulted as follows
    1357 cals, 70, 15, 15 % F,C, P respy, with Carbs at 50 g. Finally 1434cals, 60:24:15 with Carbs 90 g.
    I may have to reduce something which will not upset her. As. I am targetting 1200 cals. Impossible today.
    Have 3 or 4 alternative meal plans I want to paste on Kitchen door from the Intake Analysis on the phone. The better combinations. Ready reference
    well in advance. Impossibly small qty cooking.
    Your advice, if I have reached BMI = 20 stop wt loss., You feel no need to increase Cals, if I otherwise feel active, can walk a few kms without fatigue etc.

    I am making an arrangement I can stand and work on Computer while watching TV. Because I do spend a lot of time on Computers, smartphones etc. That is also exercise. Apart from walking. A little difficult for a Diabetic Neuropathy person.
    Vepa A Murari
    PS For information of other readers, Dr Kane is Doctorate from MIT, US,A. a retd Senior Research Scientist in the Chemical Industry with a MNC, who made his hobby of studying Ayurveda, and Health of Humans and Veterinary, and Agriculture, Into practical, developments. His books are available for both US and Indian readers on Amazon. He lives in Pune.

  • vepa A Murari at

    Dear David,
    I have a query to make about the
    ”A low-carb diet isn’t a no-carb diet. In fact, the glycemic index is as important for those of us who eat 50 or fewer grams of carbohydrates a day as for people who use insulin or pills”
    ”At the end of 2007 I switched from relying on pills and the glycemic index when I decided that a very low-carb diet was safer than using medicine, which always has side effects”

    By low carb to how much? And what makes up the balance? And how many cals.? And has it made it possible to eliminate pills.? And what is meant by “‘not relying on pills” ? And what level of sugar Control? And age of person?
    I am 79 yo. While taking in hand a thorough re-look at my Diabetic Control after 33 years as to why I got into serious Diabetic Neuropathy problem, in spite of being assured the 1 Ac was a comfortable 6.5 for almost 10 years, I learnt a lot many new things of what I can and cannot do on Diab control and the AHA Treatment Protocol (TP), which makes sense. Covering the need of different age groups.
    (First of all let us understand 6.5 means the sugar control has been right 50% of the time and bad 50% of the time. Not much comfort)

    For people over age 75 and life expectancy less than 10 years, the opinion is a strict 1Ac control may be risky (because of going into Hypo), and that any benefit by so late an attempt to improve matters IS INVERSELY PROPORTIONAL TO LENGTH OF TIME PERSON HAD DIABETES. In my case that is 10/33. But no reason to stop attempting better control. Better late than never. If I live 20 years more, benefit 20/33. Means un-assisted living may be longer.
    However the TP suggests think of what type of control – one time morning Fasting PG, or more frequent viz before sleeping and morning, or between also. The last may be for those on fast and slow insulin. For the others on Oral Tablets, the choice is based on age. More frequent for younger people. That is when GI becomes very important.

    Not aware of the above, I did attempt strict control, improving from 6.8 to 6.1. On by not exceeding 60 gms Carbs on a 900 to 1000 cals intake over 4 months and continuing, 4 to 6 times a day checking with strips. Adjusting in a 3 Tab combination – very fast acting Repaniglide,, Medium acting Sulphaneuryl Dianorm 80, Metformin 850. 3 times a day.

    I have plotted graphs for 10 different combinations of cals and tablets, the food being living on biscuits Mcvities Digestive, for accurate measurability of Cals. Also Cracker Biscuits. The former is 40 cals and latter 30 cals/ biscuit.
    The wrapper will indicate Carb, fat, protein content. They are both appx 5 gms carbs per biscuit.Since I opted for HF diet, The other food items are again Cheese cubes of known composition, or Teaspoonfuls of Peanut Butter, Oils, Coconut oil, Ghee, Butter ,some fruits etc. And minimum cooked foods prepared in the house – because they are difficult to judge.

    I can send these graphs to you separately. My queriesat the beginning of my blog was after I started initially with GL/GI, there was variability checking between meals. Then the expt with Biscuits showed the carbs and med requirement. Which I compared later with using prepared carb items – simple oat flakes ALL Meals, and then different combinations. Most difficult.

    After studying Medical Studies on internet,(there was a website with 115 studies to read one after another) during the dose modifications, on effects ofSUGAR control, the questions at beginning raised by me, LED ME TO ACCEPT
    one MORNING Test, and the either the Acrabose /Vobose or the DPP-4 mechanism, Janumet, Twice a day dose Oral Medication route as the simplest AND WHAT I FOUND LITTLE RISK OF HYPO FOR MYSELF to administer. on daily basis.

    I prefer Janumet, as causing less digestive distress. These medications work by diverting part of the Carbs to the Intestines, for digestion at a later time in the digestive cycle. My recordings indicate the sugar level between meals remains a reasonably constant, depending on carbs input. It has not caused hypo be it a 10 gms carb meal nor the limits accepted for Diabetics even 90gm carb meals, AND Total daily strict 60 gms carb meals or 190gms carb, all 1000 cals, or 190gms carb, 2000 cals meal. Morning FPG can vary from 90 to 155, based on such variations.. Provided there is no snacking after 11.00 pm and morning test at 6 to 7 AM.
    Testing 4 and 6 times a day is expensive on strip cost.

    The advanantage of Janumet 50/1000 is the high (max dose 2 /day not to exceed 100 mg Sitapgliptin) Metformin 2000mg per day is safe.. And beneficial when on low carb diet, especially for those with Heart problems, and generally requiring LDL C control (to have larger particle size) PLEASE NOTE I AM NOT A DOCTOR – BUT AN ELECTRICAL ENGINEER TALKING FROM EXPERIENCE AND UNDERSTANDING CHEMISTRY OF THE BIOLOGICAL PROCESS. PLEASE TALK TO YOUR DOCTORS.
    My impression of having tried last 6 months the various Diabetic medications Doctor suggest appears “”All roads lead to Rome”‘. Unless some one is having special other problems. I have never understood the doctor’s rationale changing from one to another.

    The Point to take home I feel is
    1. If the oral medication is eliminated by merely going low carb, then it cannot be very serious diab.
    2. If diab medication is required, even after low carb,depending on how much needed earlier and frequency, the Carb diverting mechanism, definitely reduces medication frequency, tablet count, cost.
    3. My query will still be if 60 gms carbs arrived at by GL/GI is still 60 or less, when checked on a Diet diary Program. My experience is a days intake can be a list of 20 items over 3 meals and snacks. And when varying day to day, GL/GI normally covers main items. I have seen a 60 gms daily plan suddenly becoming 190 gms even in 1000 cals..
    4. Please check with your Doctor, if the carbs diverting medication can work for you – and try one of the two methods – I recommend Janumet for its Metformin. Which comes in 50/500 dose also. If Diab problem low, one 50/500 may work, or 50/1000. Otherwise 2 per day either, depending on severity.
    5. With strict Carb control, one 50/1000 may have sufficed for me or 2 50/500. But I prefer 2 per day 50/1000 for its better night and day constancy. Remember 1 day tablets covers 2 meals and snack, and assuming 2 nd dose is taken with dinner, it covers only one meal (In India our dinners are at 8.00 to 9.00 pm, later than US practice. ). What I am implying is the two doses do not share an equal food load, Inevitable. The night does has a longer time to act. IF MY NIGHT INTAKE IS LOWER THAN 10 GL I avoid night dose to avoid Hypo risk. Better to risk 225 in the morning.
    6. Generally Night hypo viz reaching 60, with proper night intake on the lower side, can happen at 3.00 am. I have noticed, unless a foolish risk taken previous night of very small intake, this Carb diverting medication seems to self correct the Hypo. PLEASE REMEMBER PROTEIN ALSO CAUSES SUGAR RELEASE WHEN BODY SENSES CARB STARVATION.
    7. I am not a Doctor. But I have read about some people being more Hypo trending than others, I know a lady who frequently goes into hypo by going for a walk. Which means the extra 70 cals effort causes sugar level drop. The sulphaneuryl was reduced. in the normal 2 tab medication.
    8. The dips in 2 tab combination can be low, if not adjusted properly. The Carb diversion medication, apart from simplification, cost reduction, I feel has a better feedback mechanism to control hypo. IN LOW CARB DIETS, and if GL/GI is taken too far, with or without medication. If Protein is kept reasonably high the risk is less. As Vegetarian in India, I find on days I run of Protein supplements like Amway Nutrilite, Proteins in a 1000 cal diet is very difficult to maintain more than 30 gms. (Incidentally the 30gms Soya Protein supplement/ day I take is an AHA recommended step for LDLC improvement). But I have not experienced a Hypo, because a vegetarian has to make up only with carbs, for a 1000 cals meal. and does not have choices of meats to add fat only or protein only.
    9. Therefore I am interested in the target levels and sugar control attempted in a low GI food selection – with or without oral medication. Pls check with a Doctor. But I would recommend from reasons explained above, if it is with medication, the feed back mechanism in the Crb diversion medicines, does a good job of in between control, equal to or better than fiddling with 2 and 3 tab combinations, very often attempted.
    10. My wife and I ARE travelling FREQUENTLY, not always at HOME. I cannot always control what food I can get for a few days. But medication is constant and morning FPG always safe. To start the next day with confidence that sugars will NOT add up over a week. As can be expected with non-diversion medications. With a limited ability to correct, Nor keep measuring sugar, when Hypo is to be avoided. Not adding weight I can control.
    11. I have graphs to explain this. Will be happy to explain.

    • David Mendosa at

      Dear Vepa,

      I have detailed my diet elsewhere in my articles, but perhaps not here. I do consume 50 grams of total carbohydrates per day or less. That means almost all of my energy comes from fat, which after reading the 2007 book by Gary Taubes I no longer fear. I don’t use ANY drugs or supplements to manage my diabetes and I manage it well: my A1C level is typically around 5.1. I am 78 years old.



  • David Mendosa at

    Dear Vepa,

    Thank you for all this useful detail. My main response to you is simply to remind you that your doctors work for you. You pay them, don’t you? The implication of this is that you don’t have to do everything that they say. This is all the more true when you know things that they don’t know.

    So I would like you to read one of my posts about cholesterol and one book that I write about in the post:




  • Vepa A Murari at

    Dear David,

    The Doctor (not my Normal Cardiologist)told me when I consulted him about risk of continung with a High Fat diet, a month ago,with my Diab and CVD history, but recent Test Reports, said this is AHA recommendation for 30% reduction of CVD MI risk. A high Safety improvement for anyone with both Diab and CVD risk like me. With 15% risk.My usual Cardiologist has avoided it for 20 years. I thought I will try for a month before I meet hi. July 9th.

    It was also in a magazines I was carrying with me Cover pages issue was all about on new FDA Controversial approvals on Statins to discuss with Doctor. Doubling sales of statins. It had discussed on several pages, the different views of well known Doctors and Hospitals of India – for and against. Many favoured it for some of the unexpected benefits – a word paleonthopic. —–I think effects like this.

    ATP3 of AHA this doctor said look up. Recommended I think when CVD risk more than 10%. I have not downloaded ATP3. Have downloaded Reactions USA. Normal dose is 80mg when given for LDLC Reduction and 10 mg for avoiding clots. I have been prescribed generic version of Lipitor. This TP is followed in this Hospital with Japanese Collaboration

    Lipitor is safe from all accounts that my Neuropathy is not affected. Using last 20 days see no bad effects. But there is anther Statin proved as no effect on Diabetic Neuropathy. On LONGTERM STUDY. Complete info on Statins. I have downloaded it on my laptop. Have to locate it. Ithink I pasted in a 27 page Doc of what all a LC HF Dieter with CVD Risk. has to observe from begining and body marker precautions going forward and other issues to guide a few relatives who have asked about LCHF died.

    I can forward the entire RAW doc unedited, but understandeable. Lots of info you already know though, including your blogs also.

    WILL BE CONSULTING MY Normal Cardiologist and NEURO IN FEW DAYS on return to my city PUNE.About this issue. Effect on Neuropathy.

    Please Note my Logic 2 sheets – Score Card and Pririty of Action sheet – for LDLC reduction now, 25gms /day of Soya Protein, (possibly ATP3 and downloaded st. )

    A senior Endoctronologist at the same hospital, with my Lipid/ Lipoprotein tests and Thyroid tests, who I consulted casually on HF, changed medication to this Janumet 2 tabs /day, when I said I was on LCHF diet. I was surprised, but very convenient medicine. In accordance with LCHF and Metformin sites. In spite of T3 Lower by 2 points, he explained that because Tsh has not increased it was safe to continue my HF Diet. I thought he might say I was undernourished. I haven been eating about 300 cal less than BMR reat of appx 1300 cal last 5 months.

    Therefore in the final analysis,above 75yo, AHA now does NOT expect 80 mg Statin to be prescribed. Only 10 mg preventive dose.

    Doctors are not supposed to discuss/recommend LDLC figures but look at hsCRP AND ADVISE Statins. 80 mg. at other ages Agitating Doctors in US how to break years of the 70 LDLC figure advice they have been instrucred earlier for years. to tell patients. An embarrassment. Have this downloaded. in 27 page Doc Word. Easy to send across.

    Now there is a debate going on in UK and US to make10mg available OTC without prescription.

    Long reply but full picture.

    Just finished morning coffee with 14 gms Coconutoil, towards my 60gms Fat intake for the day My smartphone Diet will analyse as per AHA and will tell me end of day You have taken 25 mg Sat Fat(all varieties put together) which is more than 7% permitted. THIS Irritates me.

    I have changed food details of Coconut Oil in the program, shifting Coil Sat Fat 92% to Mono, to avoid seeing a high figure every day.Anyway it is now considered much better than Olive Oil and popular with PAaleo Crowd. And general Population.

    Have to send you my interesting experiences to your.blog. about establishing limits my body can withstand diff type fats in a day. Tallies with an Internet Article url I will send to blog. Actually two- will reduce length of blog.


  • David Mendosa at

    Dear Vepa,

    I hadn’t heard that statins might prevent clots. Where did you see that?



  • Vepa A Murari at

    1AC dropped from 6.8 to 6.1in 4 months, and BMI IS 20, WELL WITHIN AHA standards on the Risk Card..

    LDLC high (137**) but compensated by APOAI=166 (Low CVD risk), APoB= 101 (LOW CVD risk and more powerful independent predictor of CVD than LDLC and of MI occurrence.) and hsCRP=1.0, Hyperlipedemias can be ignored – when ApoB is safe.

    BUT AHA STILL SAYS advise Statins low dosage 10mg to prevent clots, NOT for lowering LDLC as is expected prescribing 80mg. HF is not going to complicate. And can be continued.

  • Vepa A Murari at

    Dear David,
    This is wrt GI Index Still matters. I am now in the 6 th month of LCHF dieting.I started with you GL tables to limit items to GL 40 to 60 / day viz portions to choose. Why I have said in this forum earlier with excellent results.
    About 4 months later I began to view ac LCHFstarted using Cal Counting Software.
    Meal plan comes almost same either. This Software was to be able to discuss with myCardiologists unhappy with exceeding Sat Fat recommendation of AHA. The mimicronutrients break up is very handy for discussion. (There is today an ATP3 of ,AHA which will accommodate the diff with LCHF advocators- next post).
    A feed ago Ichanged to MyNetDiary software(only $3 one time) on smartphone if Desktop usage is skipped. Awesome REPORTS AND info on missing nutrients.
    With more quantitarive data I have to postqueries on experience mimicking some 3

    sites about care WHICH MAY be required when going LC. Ihave also moved to less than hmm 60 gms Carbs/ day. Last two months, I have expanded list of fat items, for a Indian Vegetarian,available in India. to provide 55%. The digestive or other problem of each as well explained in these sites,will have to have to be borne in
    .mind Especially Advanced Diabetics.

    • David Mendosa at

      Dear Vepa,

      Thank you for your report. But what about the numbers? The key ones are A1C and BMI. How are they doing?