Glucose sparing?

(Bacon is better) #41

If you only know your blood sugar was low because of a continuous glucose monitor, then you are fine. If you were wakened by symptoms of hypoglycaemia, then you have a problem.

The serum glucose is dropping most likely because your body is feeding on ketones, so you don’t need much glucose. There is some debate about whether the brain actually needs any glucose at all, but there are two types of cell that absolutely require glucose, because they lack mitochondria: red blood corpuscles and sperm cells. There may be a couple of other types that require glucose, as well. In any case, unless the skeletal muscles need to work explosively (which is not the case when you are asleep), then they are fine without glucose, preferring fatty acids instead.

Under normal ketogenic conditions, the liver is making what little glucose we need from our small stock of amino acids. Are you sure you’re eating enough protein?

(Tony H) #42

Im not in ketosis. Neither time in the past week where I had low blood sugar upon waking was I wakened by the low blood sugar itself and I didnt feel too bad upon waking but in the past month or so I have woken up once or twice feeling like I was having a hypo but blood sugar levels on those times was always fine so symptoms didnt match up with my actual reading. Blood sugar seems to stay stable when I cut out carbs, when I eat simple carbs I wake up with low blood sugar. Im still trying to determine if the same happens with complex but maybe not, today I had chickpeas with my lunch and 300g potato with my dinner which was now 3 hours ago and my BG is 5.8. As for protein I have been eating 100g-120g a day but no matter how much I eat atm I still feel hungry.


Completely normal, when you go super low carb, then eat carbs your body over reacts, which just happens to mimic diabetes, but it’s not. That’s your glucose sparing. It’s fine, you’re not, or becoming diabetic. What’s happening (is) normal. It’s just not what you’re used to.

(Tony H) #44

Yeh when I spoke to my GP she was honest enough to tell me she doesnt really know much about keto. I have read a lot about glucose sparing and was kinda hoping it would smooth out and settle down, I probably haven’t helped by jumping around with my diet in response but ive not been super low carb now for a good month so hopefully it settles soon. In order for it to stop would I need to reduce my fat intake? Obv im thinking that if it is causing temp insulin resistance and im still eating high fat whilst adding carbs it will presumably keep using fat rather than accepting glucose?

(Bacon is better) #45

That sounds as though you are still insulin-resistant, and the resulting large insulin response is driving down the blood sugar excessively low. The best cure is to stay off carbohydrate for a while, until you become insulin sensitive. Then you won’t experience such wild swings of blood sugar and blood insulin.

(Tony H) #46

Yeh I really cant make sense of it atm and my doctor is no help. I checked my sugar when I woke up during night (5.1) and again upon rising this morning (5.4) at which point I was likely around 12+ hours fasted so no problems there but Ive woken up with one of the worst headaches ive ever had again. From what Ive read on glucose sparing it should return to normal when you resume eating carbs so im none the wiser whats going on.

(Tony H) #47

Just got off the phone to my GP. Have been referred to endocrinologist but he said in 36 years of practising he’s never seen reactive hypoglycemia in a non-diabetic. Still clinging onto the hope that like you say my body is just overreacting following the diet change and it will balance out but for now I have gone very low carb which likely wont help it to balance?. It obv stops my spikes and therefore the crashes but Im obv still very concerned.I was tested for diabetes and got 5.2 so that looks unlikely at this stage. As expected the doc advised against going keto telling me my body needs carbs to function optimally.

(Bacon is better) #48

You might want to remind your doctor that there is no known carbohydrate deficiency disease, and that the body only needs a very small amount of glucose circulating in the blood, which it is perfectly capable of manufacturing, if needed.


That’s all it is man, it’s EXTREMELY common, just not in your doc’s world. In the keto world, it’s a well known thing.

May be the queue for a new doc, because that’s factually wrong. There’s not a human alive that (needs) carbs. I say that as somebody that does CKD/TKD and eats more carbs than more here, but that’s for performance in the gym and for muscle gain, still don’t (need) them though.

(Tony H) #50

Fingers crossed. I’d still like to lose 50 lbs so at this stage to undo all the years of abuse I have put my body through I think I should stay on keto for a while and do a reset and then maybe down the line look to start very slowly introducing some healthier carbs and hopefully I have a better reaction. Atm my energy levels are so low I’ve stopped exercising and Id like to get back into weight training a few times a week and really push for a healthier life. Ive always been somene who enjoys exercise but my sugar addiction has always kept me on the wrong side of fit and healthy, at 34 Im plenty young enough to take control of it. Thanks for your input people, appreciated.

(Bacon is better) #51

You may even find that, once keto-adapted, you won’t miss the carbs, and won’t need to add any back in. It happens.

(Allie) #52

Energy levels will be low while your body is adapting to the different fuel source. You have to be patient while it gets used to the new way you’re asking it to operate.

Your doctor sounds like he is only going to add to your worries by feeding you bad info.

I’ve been playing around with adding carbs again for gym / muscle gains reasons but have now gone back to just proteins and fats as my body actually functions so much better without carbs now.

(Tony H) #53

Yeh Im only 2 days in and energy wise I dont feel great. My baseline fasting BG levels upon rising when eating carbs was usually between 5.3/5.7. Last 2 days Ive had 4.4 and 4.3 so automatically much lower on keto, yesterday had about 20g net carbs, first day little bit more. Is this normal this quick?

(Bacon is better) #54

Yes, it’s normal. There are two processes: getting into ketosis, and fat- (or keto-) adaptation. The former happens very quickly, the latter takes weeks.

All it takes to get into ketosis is a low enough insulin level, and that is achieved by dropping the carb intake. How low carb intake has to go for someone depends on how insulin-resistant that person is, since the greater the insulin-resistance, the greater the insulin response will be to a given stimulus. (It is possible to regain insulin-sensitivity over time, but it won’t happen overnight, which is why we caution people not to be too eager to increase their carb intake too soon in the process.) But once insulin drops below a certain threshold, the liver begins manufacturing ketone bodies and what little glucose the body actually needs.

Fat-adaptation takes longer, generally six to eight weeks in most cases. During this period, athletes will notice a drop in performance. The reason is that skeletal muscles are being deprived of their accustomed fuel, glucose, and haven’t yet re-adapted to metabolising fatty acids, so in the meantime, they are limping along on ketones. The reason fat-adaptation takes time is two-fold: first, the mitochondria in the muscle cells have been damaged from years of metabolising glucose. They need time to heal and make healthy baby mitochondria. Second, there are other cellular pathways involved in metabolising fats, which have been deactivated from lack of use, and they need to be reactivated. Once the muscles have readapted to metabolising fatty acids, they will actually pass up glucose and ketones in favour of fatty acids, a state called variously “physiological insulin-resistance” or “adaptative glucose-sparing.”

All this takes a certain amount of time. You will notice your energy level rising again over the next few weeks, but in the meantime, go easy on the exercise. By the time you are fully fat-adapted, your endurance will be back at, or possibly better than, its pre-keto levels. Explosive power will take somewhat longer to return, but it, too, will eventually be as good as ever.

(Tony H) #55

Thanks Paul, very informative. I was watching how my blood levels responded to my food yesterday. Previously Id eat an apple and some peanut butter and my BG would go from 5.8-7.1 within 15 mins. Yesterday I ate a chicken salad with avocado and my bloods went from 5.3-6 but it was much slower, took several hours to reach that high and then obv come back down to low 4s during the night.

(Bacon is better) #56

Of the three macronutrients, carbohydrate has the greatest effect on insulin. The reason is that carbohydrates (except for sugars, which are a bit different, chemically) are all glucose molecules linked in various ways. And glucose in quantity in the bloodstream is an emergency: if not dealt with, hyperglycaemia can cause damage, even death. So the insulin response is intended to drive excess glucose from the blood and into muscle (where it can be metabolised) and fat tissue (where it can be stored as fatty acids). As you can guess, too much carbohydrate over too long a period causes problems for the body, as muscle cells and fat cells get stuffed and start to resist listening to the insulin.

Fat, on the other hand, has a minimal effect on insulin, just enough to allow the body to make use of the fat. In the proper quantity, insulin is essential to life, because it helps every cell in the body use or store energy; it’s just that, like too much glucose, too much insulin also has a bad effect on the body over time. But this is why we suggest eating more fat to compensate for the lack of dietary carbohydrate: it won’t raise your insulin level enough to notice, and it is a much denser source of calories, so it takes less fat to get the same amount of energy.

The insulin response to protein depends on the context. Protein is not normally used to provide energy to the body, but is needed for various structural purposes. In a low-carb diet, the insulin response to protein is compensated for by another hormone that keeps the effect of insulin low (insulin and glucagon are both secreted by the pancreas, and they are the primary regulators of ketosis and other aspects of the metabolism). Because the liver will make glucose out of amino acids (which is what all proteins are made of), it used to be believed that excess protein intake would elevate blood sugar too high; nowadays we realise that the picture is much more nuanced than that, and the focus has now shifted from fearing to eat too much protein, to fear of not eating enough. Myself, I suspect the truth lies somewhere in between.

(Omar) #57

I thought the only reason my BG reading is between 80 and 95 is the protein (when 0 carb)

When reducing the protein/fat ratio, my BG can go down to 75 or lower.

With 150 grams of yogurt, my BG get up to 110 units

So in my case the protein does shift my BG from 70-80 range to 80-95 range.

I think if I eat more protein, I would expect my BG to exceed the 100 units.

I don’t have a keton meter. I am not sure if I get into ketosis with the description above. I usually do not think about that, I focus on energy level. I feel I get more energetic when my fat/protein ratio is high which is not always an option the way I am living.