I really love your videos. They appeal to the nerd in me. 5 years ago, in the medical laboratory where I worked, it was time for me to complete a new reference range study for A1c. I set out using blood specimens from hundreds of “healthy” individuals… blood donors. My hope was that I’d have enough data points to establish reference ranges for male and female patients to replace the single range we were currently using. As the specimens came pouring in, I used criteria given me by our pathologist to weed out prospective samples from people who were not healthy and therefore unsuitable for participation in our study. The limiting criteria were the following: normal BMI, normal fasting blood glucose, normal cholesterol and triglycerides. From hundreds of samples, using those parameters, I ended up not even having enough specimens for a single unisex reference range study. So, it naturally makes me wonder how GI participants were deemed healthy. The scourge of insulin resistance has gained a stubborn foothold everywhere in the last 50 years and gets worse every year.
Interesting story. For the calculation of the glycemic index of different foods, it's actually not that important whether or not only heathy people are studied, because in the calculation of GI, each person is their own control (i.e. the area-under-the-glucose curve for 50g of pure glucose is set to 100 for each individual participant, and all other foods are related to that person. For that reason, glycemic indices of foods don't differ that much between healthy and pre-diabetic or even diabetic populations. For studies in which they select only healthy people, there are a few key criteria based mostly on normal fasting glucose and fasting HbA1c. Cheers Mario
I downloaded the GI/GL chart and was astonished to see that the glycemic index of beer is 104 -- higher than glucose! Turns out that beer contains a lot of maltose, and maltose spikes blood sugar even more than glucose does.
I appreciate your videos SO very much! I am well-versed in statistics and science; however, it is so refreshing to hear these concepts explained clearly - accompanied by simple, hand drawn charts. I will be sharing your videos with my 76 year old mother, and I'm quite confident she will be able to follow along with no issues. In addition, I plan to share your channel with my primary care physician. I think his diabetes patients could benefit from your easy to understand videos. Thanks again!! 🙂
Excellent explanation about foods not rating as good or bad. My decision on what food to chose is by asking myself, “if I don’t eat this, what will I eat instead?” So one choice may not be bad but instead I chose a better alternative. Knowing the GI/GL of foods give me better choices. Thanks ! ❤ Sheri J.
I really love this channel. Precise information and limited to what is known (not claims extrapolated far from what is evident). Thank you for the content. Personally I'm not aware of problems with my blood sugar and no-one in my family has problems with it anymore. So I have no personal interest in watching this. I eat according to Harvard's Healthy Eating Plate and Pyramid and I eat vegan for ethical reasons (with a few additional things that do not break the overall pattern described by Harvard Health). Since I started doing that I have no health issues related to food. But I listened to this and the glucose monitor video just for the scientific education. A few questions came to mind. I ask them in a separate comment.
These questions came to mind: 1. From a statistical perspective: Why is an average used? If there is variability, then median would be a much more robust measure to get a "typical" value. It's a common thing to use the average where the median would be the better option. So it could be just one of these cases where something was chosen but not the best option. Or is there some scientific reason for using the average instead of the median? 2. GI and GL are defined using an area (L1 norm). It would therefore give a very high short spike the same numerical value as a longer flat elevated blood sugar. Is that a non-issue in real world data? If not, why weren't measures of "spikyness" used (for example mean/sd) instead? Perhaps I don't precisely understand what property we want to quantify with this. But these are the questions that came up to me. 3. Interesting to me was that whole grain bread/pasta and white bread/pasta are so similar. Personally I have very different reactions to those anecdotally. Satiation is a big difference (which is not addressed by GI/GL) but also after eating most refined carbs things (not an issue for me with white rice and it was only an issue on the previous diet) I felt weak after a while (with a sensation of tingling). We called this (not supported by data) having low blood sugar. And eating carbs helped (refined carbs faster than others). Is this sensation based on blood sugar? But it's not reflected by GI/GL. Are there other measures that reflect this? 4. As you already alluded to in the previous video a lot of things influence these. Food eaten in a meal interacts with each other and blood sugar response of a meal is not just the sum of blood sugar responses of a the parts. I wonder if resistent starch (cooked and cooled pasta/potato/rice for example in a cold pasta/potato/rice salad/dish would have significantly different GI/GL) increase would change something. Or are they approximately the same? If they are different, what are the values in the poster refering to? I suspect they are approximately the same because fiber has essentially no effects on it either. So why would resistant starch.
Great questions. I will address #3 and #4 in videos in the very near future, so I hope you understand if I don't respond to these here (would be a long response ...). Question #1 is a good one. For the GI, the data are mostly approximately normally distributed, so the mean and the median are pretty close to one another anyways. I guess there is also the thinking that if there is some skewness in the data, with a few people having massively larger glucose AUCs after a specific food, one would want to have that reflected in the GI value (which wouldn't be the case if the median was used). To me, this does make sense. Question #2 relates to another limitation of the glycemic index that I thought was too technical to discuss in the video. You are totally correct that a food that spikes glucose very quickly could have a similar GI as a food with a slow and steady rise and fall. The specific pattern is not at all reflected in the GI values, and I think this could be one way to improve upon the GI in the future. Thanks again!
"Every whole food ... has some benefits and some potential downsides. So, what I'm hoping is that we all start to move away fromt this idea that we should look for food t5hat is perfect in all regards." Agreed. But rather than moving away from finding "perfect" food, we should move towards finding food that is best suited for each individual. Yes, every food has benefits and downsides, but the downsides are not the same for every individual.
Hi Sir, this is the first time I came across your video. The way you explained and break down things it makes so easy to understand. Thank you very much!
Thank you! That was very informative and much clearer than when I read about it the other day. The poster does not say how big a serving size is. Tbh, I would find it much more helpful to have glycemic load for 100g servings - then I could just calculate for the serving size I'm going for!
That's a good suggestion. I struggled with this as well, but decided to stick with this definition of the glycemic load because that's how it's usually defined in scientific studies and on most websites. I am considering publishing a revised version of the paper that includes the portion sizes for each food on the back though. Cheers Mario
That is excellently explained, very useful information! Now I see that I can eat a lot more items than I actually thought, and some others I can actually enjoy in moderation.
Thank you again for this life changing information on Giycemic index and how it affect health outcome. I appreciate how your explanations are clare backed up with science. I will use this information to choose my foods wisely so I can benefit from the health benefits.
It all depends so much on what food you eat with the higher glycemic ones And the order in which you eat them! Let's go back to the basic way we used to eat before the avalanche of highly processed foods. Start with a salad or vegetables, vinegar also helps! Then eat the protein and what is considered fat and finish with the carb ones, like rice, pasta, bread and desert! Greek yogourt is also very good to avoid peaks we might have with fruits! Move a bit after eating... And avoid to start the day with sugar loaded food, they will leave you craving for sweet until you go to bed! And... sugar is sugar! But eat your chocoate cake at the end, never on an empty stomach! 😁 Thanks for this video!
I love your direct and serious approach to topics. Nevertheless, I would invite you to explain what the GI curves really tell: do I produce more/less sugar, do I have to burn his sugar more/less intensively, what does our body expects us to feed it with? Please move forward to the next more practical step. Tks!
In short, whenever we eat something with carbohydrates, the food poses a challenge to our bodies. That is because our bodies try hard to keep blood glucose levels within a pretty narrow range of about 70-140 mg/dL all of the time, because blood sugar levels that are too low or too high pose health risks. If you eat something with a high glycemic index (GI), that means that your body needs to work extra hard to maintain blood sugar within the normal range because the food raises blood sugar more than a low-GI food, even if you eat the exact same amount of carbs from both. So, in a way, by eating low-GI foods, you help your body keep your blood sugar levels in the normal range. If you haven't seen it yet, I also recommend you watch my video on the regulation of blood sugar: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Yg9AS2sfY9Y.htmlsi=dkPRhymHLkcbEfkY Best, Mario
Do you have info concerning the GI / GL of raw potatoes? I’ve eaten them this way as a snack, with a sprinkling of salt, ever since I was a kid. As an adult, I still eat them, as well as raw purple sweet potatoes. I typically add them to salads. Thanks for the content.
Hello, not a hater here, I like your videos, always cool to spread good knowledge like this, but I have to inform you I think there is a tiny mystake in your poster picture : the low fat milk should have higher GI than full fat milk. Anyways it is not a big deal. Keep doing this good work. To be honest for now I didn’t find any thing I didn’t know about glycemia in your videos, but making tests on myself I saw and noticed in real life everything you are explaining, so good job! 👍🏻
Hey Ninja, according to the updated tables of glycemic index I used (glucose as reference food), the GI data for low-fat and full-fat milk shown on the poster are correct. If you'd like to check, you can find the reference on the blog post associated with this video. Thanks for your feedback though. Cheers Mario
@@nourishedbyscience Thanks for your fast reply, for sure I I will take a look to it. I find it odd though… More fat into It should lower the GI… What do you think about it? Maybe you have an explanation for it that I ignore…?
I just came across your videos in search of understanding what caused my triglycerides (363) to shoot up, HDL (54) on a high carb low fat (vegan) way of eating. A1c 6.0 which I’m trying to lower. I’m desperately trying to find balance so I lowered carbs avoiding white rice and potatoes, I do have a slice of sourdough now and then with humus, tomato and greens. Recently videos saying to eat protein to bring down triglycerides but I’m afraid it’ll increase my cholesterol. I really want to find balance in my lipid panel..
Foods alone aren't the cause of elevated cholesterol. Elevated cholesterol is a response to Inflammation and someimes just genetics. Lots of lies have been sold to us on cholestrol. You don't absorb cholesterol from food. You need protein and healthy fats, vitamins and minerals. Focus on anti-inflammatory food combinations and removing environmental toxins, decreasing stress getting good sleep. Too much to say about all this.
Question: if, say, i make a morning smoothie that contains 3 ingredients, a banana with a GL of 7, blueberries at 8, and greek yogurt at 3, will those combined ingredients make my smoothie a GL totaling 18, spiking glucose unsatisfactorally?
With all the information on diet it is hard to get a clear picture of Health. I am beginning to think Glycemic index may give the clearest view involving many aspects. You mention and show your chart but didn't show how it can be accessed. If you know of a large list it would be appreciated. Good topic!
Jerry, thank you. I see the glycemic index as one of many factors we may want to consider. It has an important limitation, as I'll share in the next video. And, maybe obviously, healthy eating isn't just about minimizing blood sugar levels, even though that's an important aspect in our current food environment. You can download the poster here (the link was in the description of the video): - LINK TO DOWNLOAD GLYCEMIC INDEX / GLYCEMIC LOAD POSTER - nourishedbyscience.com/the-glycemic-index-and-glycemic-load-of-common-foods/
Thanks for the info, I enjoy learning from your videos. I have reactive hypoglycemia, so your explanations are very interesting for me. What about the insulin index of foods? Is it of any use? Thanks
Thanks. I really enjoyed watching this during my post prandial walk on the treadmill. Does it matter whether high or low GI/GL as long long as you spend it? Also at what level of blood sugar does it become unhealthy?
I guess with 'spending it', you mean exercising after the meal or going on a walk? Always a good idea, I'd say. As to when blood sugar is unhealthy, I sugest you check out this video here, why I discuss this topic in some detail: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Fce5Tyul6ng.html
All I know is both my daughter and I., aged 55 and 75, consider ourselves "allergic" to oatmeal and get the shakes within an hour. Also very hungry again within an hour, yet a friend of mine, (my age) who died 2 years ago loved her steel cut oats daily. I recall watching in wonder as she enjoyed a breakfast that I considered a poison to me! I miss her. 😢
It is quite common for people to experience blood sugar spikes to oatmeal followed by what we call reactive hypoglycemia, i.e., low blood sugar. Low blood sugar is probably why you are experiencing the negaive symptoms. These could include shaking as you say, but also a faster heartbeat, sweating or cold shivers, anxiety etc. This here is an interview with an MD who experienced the very same thing for years before figuring out what these symptoms were caused by: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kxUP0zzBECA.html If you think this could be the same for you and your daughter, then it will be essential to avoid the initial blood sugar spike. Here are some ideas on how to do that (other than not eating oatmeal): ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-yg0Y3eNSANg.html Best wishes, Mario P.S.: Very sorry for your loss.
Hi Mario, the Statin debate is raging and my GP has been trying to get me to take them for years. I have tried a few times but have had side effects. Could you please address this issue in one of your videos showing how food can help us not to need statins?
I may make a separate video about the insulinemia index at some point. It's related to the glycemic index, with some exceptions. Dairy foods, for example, tend to have a low glycemic index but a high insulinemic index. The insulinemia index is less well established, and it's less clear how to interpret it, but it may still make for an interesting video. Cheers Mario
Why eat veg only also spike ? Today I steam and ate bitter melon, eggplant, shiitake mushrooms, cut raw capsicum, cut raw red onions, half fresh lemon juice and fish paste (no flour, no preservatives, only filtered water tenggiri fish tofu fish and himalaya salt) garnish 2walnut, 2pecan, 1 Brazil nut. May I know why ? Before food 4.6 after food after 2 hours 6.3
It's certainly more challenging for a vegan to always include a sizeable portion of protein in each meal, but it can be done even on a vegan diet. If you are ethically (or otherwise) OK with including some dairy, eggs, or fish in your diet though, that would certainly give you some additional options. Cheers Mario
In general, the scientific data suggests that its best to minimize foods with a glycemic index > 60, and also those with a glycemic index < 60 that are fructose-rich sweeteners (high-fructose corn syrup, agave syrup, maple syrup, honey, table sugar etc.). For more detail, check out my separate video about the glycemic index and health outcomes. Cheers Mario
"By convention this is divided by 100 to make numbers smaller" - no, you are converting the GI from a percentage to a fraction between 0 and 1 when you divide by 100.
Sorry, I think the line you mention is related to GL, not GI, right? To calculate the GL, you multiply the GI by the g of carbs in a food/serving or food, and then divide by 100. That way, a GL of 50 should be interpreted as the same glycemic load as 50 g of pure glucose (in that food, or a serving of that food, dependng on what amount of carbs you use to calculate the GL). Cheers Mario
I ate a pretzel today, and my blood glucose went to almost 350 and then dropped to 53! So, I had to have protien and a protien bar to get it ba k up above 70. No more for me. Lol, I guess I will stick to being a carnivore. I was a ketovore.
If you watch any of my more recent videos, particularly those where I talk about the second meal effect and the first-phase insulin response, you will notice that being on a very low-carb diet tends to impair glucose tolerance and particularly the first-phase insulin response (I'll leave a few links below). That may well be temporary, but if you suddenly eat a lot of carbs while otherwise following a low-carb diet, being ketovore likely contributed in a major way to the massive blood glucose spike. That said, please be careful because such a substantial spike probably still means that you have diabetes. And while being on a very low-carb diet such as carnivore can keep your blood glucose levels largely in check, the changes in your body that cause the diabetes (such as deposition of fat in and around inner organs, or low-grade inflammation) may still persist. And while diabetes increases the risk of other diseases such as cardiovascular disease partly through elevated glucose and insulin levels, the increase in intra-abdominal fat and inflammation biomarkers may also contribute. If the ketovore diet helps you lose weight, then those other factors would also be gradually improved, but I would still be sure to discuss this with a healthcare professional. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-LVw60RIhbzg.html ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kxUP0zzBECA.html Best wishes, Mario
So volunteers actually ate over a kilogram of yogurt in one sitting for these experiments? Even if that did happen the time it took to finish it must have had an effect on the results
Yes, they must have to get to 50g of carbs. And I agree, this is partly why yogurt has a lower glycemic index: you just cannot eat the carbs quickly enough. And I think this should go into the calculation of the glycemic index. Partly, it's a problem of high-glycemic index foods (white bread, cornflakes, potatoes, fries, soda) that they can be eaten so quickly; it's a huge challenge for the body to keep glucose in the normal range when glucose molecules from dense starchy foods enter the gastro-intestinal tract all at the same time. Cheers Mario
Scientifically, Glycemic Index is a very poor predictor of health. The same person can eat the same food at 3 different times of the day and get completely different results. Now add the complexity of meals eorh different kinds of foods …
Or ... the differences in the glycemic response to the same meal at different times of day can be explained by .... the different time of day ...;-) Glucose tolerance is known to be highly variable, based on a number of factors. For example, glucose tolerance is lower in the evening than in the morning. Glucose tolerance can also be reduced if the previous meal was low in carbs, fiber, or protein. There are a lot of determinants of the glycemic response to any given meal, and that's where the value of scientific experimentation lies: the glycemic indicees of different foods were assessed in experiments in large number of people while standardizing known determinants of glucose tolerance. So while I agree that the glycemic index has some limitations, those that you point out are, IMO, not among them. Hope this makes sense!? Best, Mario
@@nourishedbyscience Thank you for the detailed explanation. My reasoning is that for most people eating The Standard American Diet , being focused in the Glycemic Index is kind of useless. Chronic obesity and the related health issues are due to eating highly processed foods combined with a sedentary lifestyle. Fitness buffs and skilled athletes, yes, the Glycemic Index is useful. For normal people, getting them to eat Whole Foods and getting moderate exercise is much more important.
Can full fat aged cheese raise blood sugar levels and therefore HbA1c? How if it has zero carbohydrates and body is not able to fabricate sugar from fat and protein?
@@nourishedbyscience That's really strange because in the past I was not taking anything of cheese and my HbA1c was 4.8. I added aged cheese to my diet, just cheese and not accompanied by any other thing except olive oil and now my HbA1c is 5. Not so sure that aged cheese is not raising blood level sugars at least in my case.
The biggest lie about the glycemic index and load that people are told is that an index of 55 or a load of 10 is already low. People are told to eat oat meal and bananas as low glycemic foods to lower their blood sugar and people believe that's already the best they can do. The second biggest lie is that foods of near zero glycemic index and load are rarely mentioned so people don't recognize they are being fooled. If someone is really interested in a low glycemic diet, they would/should eat food with a glycemic load of 0 to 3. Not more.
I do think many people in the low-carb community go a little bit overboard in their enthusiasm for their diet, and forget that healthy people with reasonably good glucose tolerance can eat higher GL foods quite safely while keeping their blood sugar levels within the normal range (i.e., below 140 mg/dL) at all times. Personally, I find the assertion that foods containing any carbs are 'unhealthy' is not supported by the cumulative scientific evidence, and is potentially quite harmful and at the very least confusing. The literature is full of examples of entire populations or countries eating high-carb diets quite successfully, with very low rates of obesity and type 2 diabetes and a much longer lifespan than the US. Look at Italy and Japan, as two examples. The same cannot be said about high-fat diets: those few populations that have traditionally consumed low-carb high-fat diets, such as the Inuit or the Maasai, had very low life expectancies, and the Inuit at least evidence of pretty substantial degrees of atherosclerosis. It therefore isn't clear to me at all that healthy people with normal glucose tolerance benefit from cutting carbs and eating more fat, as you suggest. At the very least, the scientific evidence supporting long-term health benefits of such a shift is quite thin. Best, Mario
There are certainly individual foods that raise blood sugar more for some than for others, but it's also a good idea to test a food several times if you think it has an overly large effect on your blood sugar levels, because any one test can be false high (or low) for a variety of reasons. Best, Mario
