Active Low-Carber Forums - View Single Post - LC Raises Blood Sugar Over Time?

Quote:

Originally Posted by coachjeff

2 hours after the lunch of 8 ounce chix-breast with salsa, green beans with Parmesan, small apple, and ounce of peanuts I tested my BG twice about 60 seconds apart. First reading was 193, and second reading was 187. So about 190 basically. I'm guessing that is NOT a good number at all to have a full two hours after a fairly moderate carb lunch (37 grams net-carbs, after having had ZERO carbs for breakfast).

Especially considering that I lifted weights right before lunch.

The weights thing could go either way, though. When I first started measuring blood glucose, I tested a lot during workouts, etc. I wasn't pushing ketosis like I am now. Fasting blood glucose was generally in the mid-80's to low 90's. Most days, my highest blood glucose level wasn't after a meal--it was during a workout. After a set of deadlifts, it wasn't unusual for my blood glucose to be somewhere in the 120's. Now that I'm eating more ketogenically, it's rare for a set of deadlifts to put my blood sugar past the 90's, and a reading in the 80's isn't uncommon. I figure lower liver glycogen levels are probably behind this--adrenaline/cortisol inducing mobilization of fuel during heavy exertion, and when liver glycogen is relatively high, blood glucose goes up. Exerted muscle will upregulate glucose uptake, but in the short term, the liver can outstrip the muscle's ability to clear glucose, as long as glycogen stores are sufficient.

http://eatingacademy.com/nutrition/...-ketosis-part-i

Peter Attia's blood glucose here went from 77 to 132 doing high-intensity training.

Quote:

Prior to the workout I consumed nothing other than my usual 40 mL of MCT oil and during the workout I consumed about 4 gm of branched chain amino acids (BCAA) and 10 gm of super starch mixed in my water bottle – so essentially just water.

Immediately prior to the workout, at 6:43 am, my glucose was 77 mg/dL, B-OHB was 3.5 mM*, and lactate was 1.6 mM.

At 7:52 am glucose was 132 mg/dL, B-OHB was 2.2 mM, and lactate was 5.4 mM.

It's a little muddied, because he did take in some very slow carbs and BCAA's. Over the course of the day, I do think using up muscle glycogen will create a sink--competition for glucose storage in muscles vs. liver, and lower liver glycogen probably equals more ketosis, less glucose dumped into the system when stress hormones are elevated, etc.

Also, on a ketogenic diet, carbohydrate metabolism needs to be very efficient. In the extreme of total starvation, it gets to the point where total oxidation of glucose is nearly exclusive to the brain. When glucose is used by other organs/cells/tissues, it's basically fermented to pyruvic or lactic acid, but then makes its way back to the liver or kidney to be made back into glucose. The anaerobic portion of exercise can at least theoretically be satisfied without much loss of carbon from the glucose cycle. If a person on a high carb diet lifts weights, muscle glycogen is broken down and used in both aerobic and anaerobic metabolism, in a well-adapted ketogenic dieter it should be spared for primarily anaerobic metabolism--this efficiency might lose us much of the glucose "sink" that glycolytic exercise would provide to somebody on a moderate or higher-carb diet.