Some assumptions are so obvious no one bothers to state them, or even remember them.<p>Assumption: Medical professionals are trained to use Evidence Based Medicine (EBM).<p>One might assume that EBM means something specific, and I'm sure it does, but that specific thing is different for different people.<p>One thing that EBM sometimes means is: common sense is no substitute for evidence. There are uncountable times that common sense has been wrong in the medical context.<p>So, you have a lot of people commenting here that this is obvious common sense, but many medical professionals will pull out a reference chart of caloric content and glycemic index and say "look at the evidence".<p>So, it is very useful to do studies that bring evidence to common sense.<p>---<p>My other pet peeve with EBM is that it does a poor job of understanding that different interventions work for different people - it is time consuming and expensive to do that kind of investigation, thus some/many medical professionals do not understand or believe it.<p>This comment is intended as a critique, not a dismissal.
Blood glucose is dependent on more variables than just what you eat.<p>Decreased sleep slow-wave activity (not just sleep time, but the actual restorative function of sleep) significantly decreases next day insulin response [1].<p>This is my area (I work in neurotech/sleeptech), but other things that come to mind are changes in changes in gut biome, which can be altered by previous meals, and I assume is always in flux (not my area of expertise), hormonal changes, I'm sure there are others.<p>However, the conclusion that it undermines the CGM measurements. In fact, I think this makes CGMs more valuable, not less. For those without diabetes, I always thought you'd use the CGM for a few weeks, figure out what your body responds to, and then sort out your diet.<p>This shows that it isn't that simple, and that we likely need to be monitoring more regularly. If my breakfast spiked my glucose unexpectedly, that may be a signal that I should change my lunch in order to reduce the likelihood of another spike. It becomes about constant management, rather than a 1 time look under the hood.<p><a href="https://doi.org/10.1016/j.sleep.2022.03.005" rel="nofollow">https://doi.org/10.1016/j.sleep.2022.03.005</a>
I've been diagnosed with Type 2 diabetes and wear a CGM. I find that my blood glucose spikes much later than what is suggested. For example, I might eat a meal and my blood glucose doesn't spike until after 2 hours. When it spikes, I see the body react with insulin and it drives my blood sugar levels down, so I'm not sure if I actually do have T2D or if this is just how my body works.<p>Another thing I've noticed is that if I eat a very rice-heavy meal, my blood sugar levels may rise throughout the night. I don't think this is insulin-resistance but rather my body digesting the rice. You can't expect the body to digest all the rice in 2 hours, can you, there certainly must be parts that are protected from the stomach acid until much later in the digestion process. So that feeds into the high blood sugar levels overnight in my opinion.<p>I think if anything, CGMs have opened up the idea of what diabetes really is and how different bodies handle blood sugar. I think I'm borderline T2D, not full-on T2D despite what my doctor says, and I've started wondering if my blood sugar has always been high, but normal for me. On average it's about 120 mg/dL, but I do see my body react properly to new sources of blood sugar and drive it back to "normal" levels, so the idea that I have insulin resistance doesn't make sense to me.
I've been working in this space for seven years, this isn't new. There have been big studies from the UK in 2020 [1] and Israel in 2015 [2] about this.<p>Some of my learnings:<p>- Don't start your day with a large amount carbs. Have some insulin in your blood before eating that big bowl of oatmeal. Or just go for some yougurt with nuts and seeds.<p>- The classical order of a three course meal (salad first, then main dish, then dessert) is pretty good in terms of preventing glucose spikes.<p>- Going for a walk after a meal is great for bringing glucose levels down.<p>- Eat at least 2h before going to sleep. Having high glucose levels disrupts sleep.<p>- Alcohol lowers the glucose response of a meal, but is still bad unfortunately.<p>- Diet Coke works. No spike vs loads of sugar with a real coke.<p>- Stress can spike glucose like crazy, e.g. being in an interview or during takeoff.<p>- If you really want to know how you react to some food, keep the circumstances (time of day, sleep, physical activity, stress) similar. There's too much influence beyond just the meal.<p>I bet that everyone who is wearing a premium smartwatch or an Oura ring now will be using a CGM now and then in the next years.<p>[1]: <a href="https://pubmed.ncbi.nlm.nih.gov/32528151/" rel="nofollow">https://pubmed.ncbi.nlm.nih.gov/32528151/</a>
[2]: <a href="https://pubmed.ncbi.nlm.nih.gov/26590418/" rel="nofollow">https://pubmed.ncbi.nlm.nih.gov/26590418/</a>
Odd, I would have expected this to be somewhat the case? Specifically, I would expect your activity leading into the meals, along with your expectations of what you will be doing after, would have some impact? Probably more impact from how hungry you were going into a meal. If you were already sated, for example, I'd expect your body to largely try and push the meal through as fast as it can.<p>Neat to see what other people's priors are, on this.
Shouldn't come as a surprise - there are so many factors involved in glucose response to food that it's almost impossible to replicate a glucose response even with a controlled intake. Sleep, activity levels (before, after, during, even days before, etc), stress, hormones, all of these are major factors involved in how glucose is metabolized.
Jessie Inchauspe [1] created a business (she's the "glucose goddess") and wrote books around the different blood sugar responses she and others have to meals, exercise, etc... I don't recall all the ideas, but here are the two I remember: Exercise before and/or after eating smooths out the blood sugar response to food. When eating a meal, it's better to eat high-fiber stuff first, then complex carbs, then protein, then fats, and eat simple carbs last (Or something like that order).<p>[1] <a href="https://en.wikipedia.org/wiki/Jessie_Inchauspé" rel="nofollow">https://en.wikipedia.org/wiki/Jessie_Inchauspé</a>
It would be unfortunate if this article were to discourage folks from trying CGMs out. I am not diabetic but have found a lot of value in using a Stelo CGM sensor. At minimum, it gives me awareness of my current state. I routinely check it before considering desserts for example. Also, I was shocked at the spikes I would get from some food. Maybe an "obvious in retrospect" feedback was drinking a bottle of (non-diet) Coke. It consistently gave me 50 unit spikes (mg/dL). Nothing came close to it, including large meals or meals + desserts. On the other hand, drinking diet coke had absolutely no impact, which was contrary to what I've read before (the body is confused and produces insulin). Another surprising observation is the effect of consuming Feta (a particular kind of Greek cheese) : no matter what else I may have eaten, a piece of feta always leads to a reduction of 10 to 20 points for at least half an hour after consuming it(!) I doubt this is generally true, which speaks to each body reacting differently.
What about the famous breakfast? One prevalent theory among nutritionists is that the breakfast has huge influence on the insulin responses during the day: a low carb/no sugar, high protein and fat breakfast will not spike your blood glucose level and therefore will lead to a more moderate response to meal intake during the day as opposite to a high carb breakfast. I think the study should control this variable as well.
Yep.<p>My wife is T1D and this is infuriating for her.<p>She’ll think that she’s cracked it, and then the next day, with the same meal at the same time, her sugar levels go high.<p>Her words: there is nothing else where you have studied for over 30 years and STILL feel like you know nothing.<p>It is incredibly demoralising for her sometimes - especially when she’s suffering also from a high/low sugar level. I have the upmost respect for anyone having to do the amount of work, to get to zero (sometimes).
As a long time diabetic (t1d) with direct relatives also afflicted with this horrible disease, it’s frustrating that we often miss the key factors in insulin resistance and fail to see how they fit in.<p>The level of serotonin and its interplay with our current level of immune response/inflammation in our body is the single best predictor of insulin resistance. That’s simply because every good thing you can do to lower resistance increases serotonin. Serotonin then decreases inflammation. When you exercise for a long period of time you are not only increasing your immediate availability of serotonin, you are also increasing your daily availability for serotonin.<p>Obviously it’s a little more complicated but from a big picture standpoint, either something is increasing inflammation in you today and increasing your insulin resistance or (hopefully) the opposite is happening and serotonin is moving your insulin through your blood stream like a mag lev train.<p>On a side note, I do love cgms.
> if an individual eats the same meal on two occasions but starts with the vegetables on one occasion but not the other, this may lead to different glucose responses to the same meal within the same individual.<p>> Other behavioral and individual factors are known to influence CGM responses.[22][6] Postmeal physical activity — even as minor as leg fidgeting[23] and walking for a few minutes every hour — reduces postmeal glucose responses.[24] Sleep quality has also been associated with changes in postmeal CGM glucose responses.[25] Emerging studies are also uncovering the relationship between an individual’s gut microbiome and their postmeal glycemic responses.[26][27][28]<p>So basically it's the impact of the parasympathetic/sympathetic nervous system and the order of food ingestion that could induce different glucose response.<p>It's interesting because I assumed that beside the nervous system, whatever order we eat our food, it all mixes in the stomach and then start to process. Negating the importance of order but studies implies it does.
I like the idea that the proliferation of LLMs become frameworks for understanding that can help advance a field or help curious thinkers come up with novel hypotheses. If the body is something like a trained model, it’s not crazy to think that it will respond to something like fake sugar (eg aspartame) with biological processes that would only be expected for real sugar.
Sounds expected? If you are glycogen depleted, it will cause less of an insulin spike. This sounds like if you fill up the same type of car with 5 gallons of gas. Sometimes it reports full, and sometimes it doesn't. That sounds odd, until you accept that you are never fully sure the gas level you started at.
Is this already pretty expected? We already knew that glucose response was highly dependent on time of day, pre or post meal movement, and whether the meal is moderated by other components like fats that can slow down the immediate impact.
"Additionally, the summarized study did not record the timing of snack and water consumption. This is relevant because the sequence and timing of subsequent meals (or snacks), as well as the food processing and variability, can influence postmeal glucose responses." - probably a factor, hydration status is huge. This result is kind of like 'duh' though.<p><a href="https://pubmed.ncbi.nlm.nih.gov/28739050/" rel="nofollow">https://pubmed.ncbi.nlm.nih.gov/28739050/</a>
i'm a type one diabetic. this is uh, not news to me. i can eat the same thing every single day at the same time and see different numbers after every meal. stress, hydration, heat/cold, fatigue, if the wind is blowing, so many other things affect blood sugar.
My mother and I recently did an oral glucose tolerance test while wearing CGMs and discovered that in us, the CGM measurements (Dexcom G7) and the reference instrument measurements (whatever Quest Diagnostics uses) virtually _never_ lined up, even when including the G7's advertised error margins. The blood glucometer readings in me didn't line up either. Admittedly this was on the first day using the G7, when it's apparently less accurate, but due to this I've been doubtful of CGM readings in me/her. I'm sure CGMs work on a population level, but for us, on that day? Nope.<p>My graph: <a href="https://i.imgur.com/FzPdH1g.png" rel="nofollow">https://i.imgur.com/FzPdH1g.png</a><p>Mom's graph: <a href="https://i.imgur.com/5DR1G30.png" rel="nofollow">https://i.imgur.com/5DR1G30.png</a><p>Discussion: <a href="https://reddit.com/r/PeterAttia/comments/1k301o4/my_ogtt_experience_or_how_i_learned_that/" rel="nofollow">https://reddit.com/r/PeterAttia/comments/1k301o4/my_ogtt_exp...</a>
Leaving aside the science, this paper draws the wrong conclusion. Just because many factors influence BG response does not mean CGMs are somehow invalid as a tool for personalized nutrition. Quite the opposite. A good nutritionist does not work in a vacuum. They know the holistic nature of BG and will tailor their recommendations to the patient based on lifestyle. (I worked on a holistic diabetes management platform)
As the parent of a type 1 diabetic...all I can say is "duh, no shit." Activity levels, emotional state, how much time between eating & bedtime, agem among other things affect glucose response.
One factor that scientific food experiments don't seem to include is <i>gluttony</i>. Presumably because it is subjective (though nonetheless real for that). Yet if people are motivated by the amount of comfort and/or pleasure they obtain from eating their favourite foods this may have an effect on their physiological response.
Here's a (Gemini) AI summary that seems to be capturing the main point that the article wants to convey.<p>```
This page summarizes a study about continuous glucose monitors (CGMs) and how individuals can have highly variable glucose responses even when eating the same meals. The study, which involved 30 participants without diabetes, found a weak-to-moderate correlation between glucose responses to identical meals, with about 80% of the variation attributed to within-participant differences or measurement error.<p>The article notes that high glucose variability is linked to increased risk of death, greater hunger, and poorer mental health and sleep. While CGMs are beneficial for people with diabetes to prevent hypoglycemic episodes, this study suggests that developing personalized nutrition recommendations for glycemic control may be more complex than previously thought due to inconsistent individual responses. The authors emphasize the need for more reliable dietary assessment and a deeper understanding of the behavioral, dietary, and individual factors that influence glucose responses.
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