Hi PaleoPhil,
yes, I used a blood glucose meter. The effect is reliable, that means I can repeat it again and again. As long as my fat intake is high, fruit causes blood sugar spikes. When I follow a low fat diet, no spikes after fruit.
Fascinating. Thanks.
The question is: Are blood sugar spikes (in between 'normal' range) something to worry about? Or are they just somthing completely normal?
Dr. William Davis apparently thinks that any spikes over 120 or so mg/dl should be avoided, but I'm not convinced of that. I think the longer term measure of A1C is probably much more important and most of the other experts I follow seem to hold that view. I'm more concerned about the unpleasant symptoms I get when I eat more carbs than I can handle well.
Like just about everything I have an open mind on the subject, though. Too often people join a certain camp, like ZIOH/ZC or 80-10-10 and then tend to adopt absolutistic and dualistic views like "carbs are poison" or "meat is poison" or "fat must be kept at or below 10% of calories" and assume that these views apply to everyone.
Zero Carbers like Lex Rooker report high fasting BG levels. This sounds not healthy, IMO. I mean, Zero Carbers always talk about diabolical carbs. And then they have constantly (!) much higher sugar levels in their BLOOD! This is a big contradiction, isn't it?
It's a complex topic. My understanding from KGH and Loren Cordain is that the high FBG that occurs from VLC in an otherwise healthy person is a natural, benign form of insulin resistance called "peripheral insulin resistance." The fact that Lex hasn't developed symptoms of diabetes or pathological insulin resistance seems to support this.
On the other hand, Paul Jaminet and Matt Stone seem to think that there could be long term negative consequences from chronic peripheral IR. Plus Paul Jaminet, Peter of Hyperlipid and KGH seem to think that chronically staying in ketosis could possibly stress the body. This appears to be a very hypothetical area since there hasn't been much research or lengthy experience with lots of people on VLC diets, so your guess is as good as mine. I'm not currently hugely concerned about it because I don't have other serious related symptoms that I'm aware of and I do currently eat significant carbs from fruits, honey, roots and occasional tubers. Interestingly, I've had some high FBG readings despite eating carbs, so either I'm still LC enough to have peripheral IR or I may want to get my A1C checked at some point.
These topics of peripheral IR and ketosis and long-term VLC seem to be generally rather complex and controversial. I have a hard time processing all of it. So if you get any insights, please let us know.