Can Your Body get Fuel from Ketones AND Glucose?

(Davy) #1

Can you body feed on say 50% ketones and 50% glucose?
Or say 60% and 40%
Or is it an all or nothing thing? for when the body goes out of ketosis

(Michael - When reality fails to meet expectations, the problem is not reality.) #2

Theoretically, no. A certain level of glucose and insulin shuts down ketosis. Really? After my Lumen arrives I will advise. :smirk:

(KCKO, KCFO) #3
#4

This is useful to me where he says he can “rig it” (in reference to eating a california roll) because I hypothesized this in reference to me eating carbs after a long day backpacking. Peter says he can eat 120 gm of carbohydrate following a bike ride and stay in ketosis. I figured that I can eat 100g carbs at the end of a 12 hr 20 mile hike and be in ketosis in the morning for the next day’s hike . . .

(Bacon is a many-splendoured thing) #5

The body prioritises glycolysis over fatty-acid metabolism, primarily because hyperglycaemia is a metabolic danger that must be dealt with fairly quickly. Ketogenesis and gluconeogenesis are regulated by the ratio of insulin to glucagon (both are produced by the islets of Langerhans in the pancreas, the former by the β cells, the latter by the α cells).

When we eat a diet rich in carbohydrate, serum glucose rises to a level that needs to be dealt with, so insulin secretion increases, shutting off ketogenesis and gluconeogenesis until they are needed again, and forcing glucose into muscle to be metabolised and into adipose tissue to be stored as fatty acids. When we eat a diet low in carbohydrate, ketogenesis and gluconeogenesis are stimulated by a low insulin/glucagon ratio, and fatty acids are free to leave the adipose tissue to be metabolised.

This makes sense, because glucose in the diet (i.e., carbohydrate) obviates the need for glucose to be made by the liver, and we don’t want ketones and fatty acids competing for metabolic pathways that will clear the excess glucose from the bloodstream. A lack of glucose/carbohydrate in the diet reduces the insulin/glucagon ratio, thus stimulating gluconeogenesis (to provide for those cells that cannot metabolise either fatty acids or ketone bodies) and ketogenesis (to provide for those cells that can use them). The muscles, of course, prefer to metabolise complete fatty acids over ketone bodies (which are partially metabolised fatty acids), but the principle is the same.

(Bunny) #6

Can Your Body get Fuel from Ketones AND Glucose?

The down side about it is the more you restrict the carbohydrates and eat high volumes of protein and fat your degree of successfully oxidizing carbohydrates goes down so it’s like a highly delicate balancing act[1].

Eating too much fat can be the same as eating too much sugar they can both be obesogenic and go directly to your adipose tissue, eat too much sugar and your mitochondria become so over-whelmed that it quits oxidizing it and starts storing it, same thing goes for dietary fat. Eat too much fructose and it goes to directly to the liver and is turned directly into visceral fat.

The more healthy muscle volume to adipose volume, the more likely you will oxidize carbohydrates and the more carbohydrates you can eat.

The problem with high fat diets for long extended periods of time is you run the risk of storing high amounts of the undesired fats like the dreaded omega 6 PUFA’s inside your adipose tissues?

Mitochondria can oxidize both dietary sugar and fats respectively.

All of it is mathematical and based on arithmetic not mere assumptions or theories.

Footnotes:

[1] Your mitochondria are what you eat: a high‐fat or a high‐sucrose diet eliminates metabolic flexibility in isolated mitochondria from rat skeletal muscle: “…Thus, it appears that obesogenic diets as those applied here have major influence on key metabolic performance of skeletal muscle mitochondria. …”

[2] “…Within each cell a group of specialized mitochondria can be found attached to fat droplets. Rather than burn fat to create energy, these specialized mitochondria are responsible for…” …More

[3] “…In order for fatty acids to get from the blood into the muscle they must cross two barriers. The first is the cell lining that…” …More

[4] “…Fat gets directly metabolized by the mitochondria. There are not multiple steps taking place for breaking fatty acids down before shuttled into the mitochondria. This means it’s a very efficient way of energy conversion and a lot less oxidation and free radicals being released by this burning process. …” …More

[5] “…In the study, the team found that animals without sarcolipin had fewer mitochondria and had trouble burning fat, accumulating more in their muscle (called lipotoxicity), which is a common…” …More

[6] “…Fatty acids provide highly efficient energy storage, delivering more energy per gram than carbohydrates like glucose. In tissues with high energy requirement, such as heart, up to 50–70% of energy, in the form of ATP production, comes from fatty acid (FA) beta-oxidation. …” …More

[7] Exercise improves fat metabolism in muscle but does not increase 24-h fat oxidation

[8] Twenty-Four Hour Total and Dietary Fat Oxidation in Lean, Obese and Reduced-Obese Adults with and without a Bout of Exercise

#7

Yes, but depends on your metabolism. If you’re working out, lifting weights or are very athletic you can pull it off. Just because you eat carbs and start burning glucose doesn’t make all the ketones disappear, they’re still in your bloodstream and you’ll still burn them. Your body will stop producing them for a while but many can pull it off and burn off the carbs while still measuring ketones the whole time. When I first started playing with that while I was very far adapted I hadn’t pulled off metabolic flexibility yet seemed more like an off switch for ketosis. Felt like crap, had a ketone reading of 0, didn’t feel right for a day or two. Now when I eat a “normal” meal I keep on going, burn off the carbs and back to ketones I go. In most cases I’ll burn through the glucose and flip back to ketones before I can even notice it on a ketone reading. Also, feel fine the whole time now. No payback feeling hungover or brain fog and tiredness.

#8

This fits with Dr. Ted Naiman’s approach. He targets his carbohydrate eating at the last meal of the day, after eating the protein and fat containing foods. He will eat up to 100g of carbohydrates from wholefood sources (e.g. tubers and vegetables) and be in ketosis the next morning.

He uses time restricted eating. Interestingly that targeted carb feeding occurs only once in the day and on the last meal, because if he eats carbs in the morning, he sometimes feels that he is chasing carbs for the rest of the day. So satiety and controlling glycemic excursions and insulin response come into play.

(KCKO, KCFO) #9

I personally don’t do much carb loading, I have rarely consumed more than 75 grams of carbs in the last three years. I can easily do 50 grams and stay in ketosis and I find I don’t like how I start to feel with anything over that.