Just when you thought all you needed to worry about were carbs and proteins when figuring your insulin doses, the Joslin does a study looking at fat. Granted the study is very small only involving 7 people. But it does point to something we all experience. Those highs after a big steak meal or pizza.
http://www.diabetescare.net/flash_article.asp?id=446877&utm_source=DC.net+-+Providers+Newsletter&utm_campaign=df4c120f75-DC_net_Provider_Newsletter_April_8_2013&utm_medium=email#.UWMZfuz_tOs.email
Doesn't seem to say anything most of us didn't already know: Meals like pizza cause spikes much later on and usually aren't worth the trouble. They didn't even mentioned doing combo boluses which is how most of us who do eat pizza manage our BG. They just refer to the "next experiment" using "increasingly high levels of insulin until they reach the optimum dose".
My CDE at the Joslin clinic sent me the link and I mentioned to her that the vast majority of T1 D's with whom I chat on the DOC cannot handle pizza regardless of the type of wave or combo boluses they use. I posted the link here because not every one is as well informed as you are Zoe and there may still be a few PWD out there who don't realize the KFC they had at lunch could cause a late spike.
I like studies like these. They do take the obvious that we all experience, then offer insight into why it is the obvious exists in the first place. It's the difference between knowing that the sun is going to rise everyday, and understanding why the sun rises everyday.
Yeah, it's a small study but if it can be demonstrated that fat intake affects insulin sensitivity, that's a fundementally different result than thinking that dietary fat is simply affecting glucose absorbtion. In other words, even if I can deal with a high fat meal by using a dual wave or extended bolus on my pump instead of multiple injections over an extended period of time, it shows that I will actually have to alter the size of the bolus, not just the timing of release.
I know that's always been a problem with high fat meals for me. Even accounting for all the carbs, gluconeogenesis from protein, and the minimal amount of glucose from fat, It seems I'll always still spike sometime later unless I just bolus with more insulin. So, according to this study, that's a consequence of a less effective meal bolus, not a miscounting of carbs, etc.
I guess the older I get, the less I truly care why something is the way it is..lol. I actually always up the bolus from the amount based on my I:C and then combo bolus that increased amount. Frankly, it is still hit and miss. Maybe if I played with all the variables (total amount bolused, percent up front and percent extended, how long extended and of course serving size) I'd come up with something that worked. But frankly it's just too much trouble and it's not something I eat very often. It's a vicious cycle because the less often I eat it the less likely I am to have enough data to find what works. So easier to have it rarely and correct for the nearly inevitable highs.
I do think some people have an easier time doing things like this, but then some people have an easier time of managing their D in general. Or maybe they just bolus amounts of insulin that would terrify the rest of us.
I like refresher courses...
It seems like the article is supporting the idea of giving things up, "if you have fat, you have hyperglycemia" vs. "here's how to cover fat" which I would think would also be possible. It's probably a marketing challenge, given the general aversion to fat in marketing and popular culture (except maybe "Diners, Drive-Ins and Dives"...) but I eat pizza, steak, big hunks of fish, etc. and do ok but I don't bother calculating the fat "boost" precisely, as I'd read somewhere that one would count 10% of the fat as converting to carbs. For me, that just falls into the catch-all carb counting, 5-10 extra G of carb/ meal that I usually toss onto the carbs to cover the protein and fat components.
I find it sort of disappointing that the article seems to tout what I've had rattling around in my head for a few years (10% of fat converts to carbs...) as a "discovery" since if had trickled down to me, I would expect what I've presumed to be a large organization (Joslin) to be ahead of me at taking it to the next level. We need solutions, not more old facts!
Ah, that makes sense, Clare. And, for better or worse, some people do like to hear things coming from "authorities".
Still, I think Acidrock put it very well when he said you would expect an organization like Joslin to be a few steps ahead not behind all of us!
I wonder why the study designers didn't test a low carb high fat option? In fact they didn't explicitly state the actual carb content of the meal, except to say that they held the dietary protein and fat portions identical in both the low and high-fat meals.
The low carb dietitian reviewed this story last week:
http://www.lowcarbdietitian.com/1/post/2013/03/new-evidence-on-diet...
She calculated that the carb content of the study's meals was 90 grams. I could never achieve anything near normal postprandial BGs by eating 90 grams of carbs in any meal. Some can; many can't. The medical and nutritional establishment seems to want to hang on to the "fat is bad and carbs are good," failing philosophy, even for people with diabetes that struggle with post meal hyperglycemia.
I eat many meals with 50 grams of fat or more (I limit carbs.) and consistently enjoy great post meal BGs. Fat is not the problem. The high fat and high carb combination is a BG disaster for most PWD and is probably at the source of the T2 diabetes epidemic.I have a bias because I'm italian, but with the right wave or combo bolus you CAN control a pizza. It's a "long run" of many hours, but you can ;-)
The above should read that the study designers compared a low fat and high fat meal while holding the protein and carb portions identical.
I read the news releases as well as the actual study and basically said to myself "Duh," followed by "watch out for the spin." We have known that fat affects digestion and blood sugars for quite a while. Even Joslin (where Wolpert is located) talks about the TAG method counting 15% of fats as carbs (we also have a group here at tuD on TAG). Fat has a number of impacts on the absorption of carbs, both the rate, variability and the amount. This result could have been predicted with great certainty without doing this study, but it doesn't mean that fat itself affects insulin needs, it suggests that blood sugar control in high carb, high fat meals is harder and doesn't work as well ("Duh"). For another perspective on the matter, our fellow member LowCarbDietician discusses this study on her blog.
And I suspect that this study was designed to support the spin that fat is bad for diabetics. Wolpert is a well known clinician and researcher, but I don't always agree with his views. For a perspective on where Wolpert comes from, watch this video from dlife from 2006. The study itself implicates fat itself as the cause of higher post prandial blood sugars a conclusion that cannot be drawn from the study. And as we can see from the press releases, this has been translated to a call to do studies of how fat reduction can improve blood sugar control. Nobody has enough of a clue to actually run a study comparing a low carb high fat meal to a low carb low fat meal and see what happens. I'm just waiting for this study to be called out as a reason to not eat fat.
I'm a little wary of this mini study. The results could be used to bolster the outdated dietary recommendations that the high carb, low fat diet is the one diabetics should follow. If they had people eating pizza for this study, I'm not surprised that the high carbs together with high fat would be harder to control than the high carbs/ low fat combo. By giving each group the same amount of protein and carbs but varying the amount of fat does not show that high fat is the culprit in causing a delayed spike in blood sugar, but in all likelihood it's high fat in combination with high carbs that causes problems.
Oops, I juast read Brian's comments after I replied, much more in depth than mine.
Never imagined I would say this, but I haven't been here in a while. I had three vitrectomies this past year so computing has been a challenge. The good thing is that my vision and P/N are MUCH improved and I am approaching normal daily function. Not that I have ever been all that normal.
I was disappointed when I read about this study. I learned this very early on here at Tud. I eat about 100 carbs per day and use fat as a tool to control my BG as well. Shortly after starting insulin I realized that using the least amount of insulin possible would give me the best results and make my life much easier (not to mention safer). So when I saw that they gave the low fat group 9 units and the other group 11 I was shocked. Maybe I'm unusual, I don't know. On average I take 1 or 2 units if any at all. The most I have ever taken at once is 5 units. I don't think I've ever done 9 units in an entire day.
It just seemed to me that they were forcing the results and not being complete in their take on them. I was hoping for some good insight to pass along to a family member stuck on the low fat high carb myth who was just DX T2. I expected better from Joslin.
In another study participants ate three versions of a meal: Standard (58G carbs), std + fat added and std + protein added. Insulin needs in the following 5 hours were monitored.
The fat-added meal did not require extra insulin even though it had 150% of the calories of the std meal, but the need shifted a little bit toward the second half of the 5 hours.
Compared to the standard meal, only the protein-added meal required significantly more insulin. The extra need for insulin was only in the second half.
Like I said, I don't see the problem with having a formal study provide quantitative evidence for phenomena that we already "know" from anecdote. For evey anecdote we know to be true where a formal study has demonstrated "duh", there are any number of studies where research has found, "wait a minute", instead. If we didn't decide to formally study things we "know" to be true, we'd still be pretty darn sure that eclipses happened because dragons eat the sun.
As far as the results and conclusions go, a lot of people have a horse in this race, including the researcher who designed the experiment, apparently. If it's foremost on the researcher's mind, it's not in the results, analysis, or conclusions which is what the study will stand or fall on. I agree that there simply is not enough resolving power in this study for conclusions such as "fat isn't good for you", but I don't see mention of any such claims in the study.
As we all have said, pizza is notorious for producing late spikes. From my own anectdotal evidence based on a sample size of 1 with 0 degrees or freedom, TAG calculations are insufficient to account for the late spikes. That leaves an effect of something indepndent of carb and protein sources of fat. If fat affects insulin snsitivity as well as absorption, that's not an indictment of fat as "bad". It's another variable to take into account if you are going to be so inclined to eat pizza. I don't see a problem with the experimental design for teasing out an effect of fats independent of the amount of carbs and protein glucose sources and absorption rate.
To me, that says, hey, if you're going to eat pizza (which typically has high carb contents, easily matching or exceeding 90g), then take a look at this when you TAG. Alternatively, you can just opt not to eat pizza, keep your carb content low which this paper certianly is not arguing against as the source of, along with protein, your insulin requirement in the first place.
It's a tiny study with a lot of limitations, many of which have been addressed here and in the paper itself. Personally, I want to see more, honest, legitimate research into these areas.
Certainly, policy is made based on research but as long as everybody has an idea of the horses in the race, including their own, the reseach can still be scientifically legitimate and sound.
Personally, if politics motivate research, so be it. Peer review can at least keep it honest. I have issues when politics stifle research.