understanding spikes

Going back to the original discussion (ie understanding spikes) I sometimes wonder if the advice to check at 1 or 2 hours is missing the postprandial peaks in some people with higher fat diets??
Many of us are aware of the 'pizza' effect whereby the fat content delays any spike but evidence about it tends to be anecdotal. Personally I know that the mismatch of insulin/carbs and fat can result in a hypo at 2 hours. This won't be a problem for people not on insulin but nevertheless it is possible that they may have undetected peaks.

I found a report of a very small study done with young type 1s and 'fast food' ( probably not the best type of food to eat but the proportions of protein/fat/carb could also occur in other meals, even with reduced overall lower quantities)
During the test meals the mealtime insulin was not given (but basal was continued) so the results show the effect of the meals on people with only background insulin. The rises were not surprisingly very high for all meals

The test meals were:
Typical sandwich meal (low GI, low fat): a ham, cheese and tomato sandwich on white bread and 295 g of Granny Smith apple slices (GI average 45; fat 34% of total energy intake of 2316 kJ).
Pasta meal (low GI, high fat): spaghetti carbonara (GI 38; fat 51% of total energy intake of 3131 kJ).
Hamburger meal (moderate GI, high fat): a Quarter Pounder with cheese and medium fries (GI average 68; fat 49% of total energy intake of 3354 kJ).The amount of fries was reduced by 40% from the standard serve to meet the 60 g carbohydrate limit.
Thai meal (high GI, low fat): chicken and cashew nuts with jasmine rice (GI 109; fat 25% of total energy intake of 2095 kJ).



They compared the change in glucose values at 2 h with those at 3 h; after the low-fat high-GI Thai meal they remained stable, after the low-fat low-GI sandwich meal they decreased and after the lower GI but high-fat pasta and hamburger meals the BGL continued to rise up to 3 h and possibly longer. The graphs show that at 195 mins the levels still seem to be on an upward trend

The research also showed that in this small group, a single CHO portion (15 g) increased BGLs by 1–2 mmol/l, depending on the GI of the food. The carbohydrate content (60g) was the same for all meals but the post prandial spike was much lower with the in the low gi/ high fat pasta meal ( with far lower overall glucose exposure).
http://www3.interscience.wiley.com/cgi-bin/fulltext/121639460/HTMLSTART

phoenix said:

Going back to the original discussion (ie understanding spikes) I sometimes wonder if the advice to check at 1 or 2 hours is missing the postprandial peaks in some people with higher fat diets??

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Possibly. But my own experience, added to many reports from others I have met over the years, is that the pizza effect occurs when high fats are combined with high carbs. For this context "high-carb" is 45gm+. I noticed that the study you mentioned used 60gm.

I realise that there are many who would not consider that to be high-carb, but I am specifically referring to the Pizza Effect. Below that level I have rarely heard of it occurring. In my own case I rarely reach that and my peak is consistently at one hour whether I am eating bacon, cheese or lashings of butter with my moderate carb meal.

However, for those who regularly eat meals that are high in both carbs and oils it can be a real phenomenon and it is certainly wise to find when your peak is after that sort of meal.

I have found that the other extreme is much more common. Very, very few people outside forums like this test at one hour after meals, or, better, test to find when their personal peak is after meals. If they test post-prandially at all it is usually at two hours. As only a minority peak at that time that is usually also a waste of a strip.

Hi Spiral.

First of all, I don't see what business it is of the Pharmacist to tackle you about the number of strips you have or what use you put them to ?

Secondly, she is probably a T! so her Bg levels are slightly different when it comes to guideline figures.
Basically waking(fasting is the same as aT2...between 4 - 7 mmol/l.
2 hrs after meals...different to a T2...........no more than 9 mmol.l.
Maybe she just thinks that 1 above isn't so bad, however I dread to think what her numbers are the rest of the time with that attitude.

Ken.

Spiral said:

I have been doing it all wrong

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From the rest of your post I'm hoping that was irony...

Spiral said:

The pharmacist told me when I dropped off my prescription earlier today. She commented that it was a lot of strips (2 tubs) and I said I got thru a lot more than that because I was managing diabetes by diet and testing to find out what made me spike. She said that I shouldn't be testing more than about once a week as I wasn't on medication.
<snip>
Her advice was not to test until 4 hours after food :?
<snip>
She assured me that I wouldn't get a spike if I did as she suggested :shock:

She went on to tell me that she goes up over 10 after meals and that this is perfectly normal. I said that I didn't think so. I'm quite worried about the health of my pharmacist if she has such high bg :?

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You're right to be concerned about her, but I'd probably be more concerned about any of her customers who believe her.

An interesting, very old piece of research (1920s), into glucose spikes long before cgms
I nothing else shows the variability of spike s between individuals. Healthy male students were given a glucose drink and then subjected to 15-22 blood tests over the following 3 hours.
Mostly (though see chart 13 which seems to take 1hr 40) the highest spikes occurred within the first 40 minutes but most had a second or even third peak , in more than half the cases the fasting level was not returned to at 2.5 hours.
http://www.jbc.org/cgi/reprint/67/3/629.pdf

Hi whatashock - You seem to be doing just fine! Stick with it!

You tell him wally. Sweet.

D.