Intermittent fasting - can I be more liberal with carbs at dinner if I'm on 16-8?

(Mike W.) #21

Robert, why do I feel like you and I are the only ones who get this? You can’t eat high fat AND have high insulin from carbs without storing it as fat.

#22

Hey @MiKetoAF - you bring up an interesting point. I believe insulin causes fat storage by triggering the cells to convert blood glucose to stored fat. I don’t think it causes lipids in the blood to be shunted to and stored in the cells.

If this is true, then if I eat high fat and no carbs and have low blood sugar, but spike my insulin with artificial sweeteners, then I don’t think I store fat as a result. On the other hand, I can see how it would tend to increase my insulin resistance over time such that I would have higher overall insulin levels and store/retain more fat over time.

Not being argumentative – I don’t know and am curious how this works.

(Robert C) #23

I think that is false (not trying to be argumentative :grinning: ) - insulin spikes will cause you to store dietary fat regardless of cause (I think).
If artificial sweeteners cause your insulin to go up - I think you will store fat just as if the insulin spike was due to carbs or stress (stress raises cortisol which gets the body to produce glucose which raises insulin).

Pretty much high insulin = fat storage (or at least no stored fat burning in a calorie deficit situation).
Not a doctor - just based on what I’ve read so far.

#24

Thanks @RobC - I generally agree that increased insulin leads to increased fat storage. I’ve altered my lifestyle to keep my insulin levels low for that reason.

My question is a bit academic - will elevated insulin cause blood lipids to be shunted to fat storage in the cells? I’m just trying to better wrap my head around how the whole mechanism works.

(Robert C) #25

Can’t help you there - I’m not that academic. Every time I go down rabbit holes I find more rabbit holes and more exceptions.

I’ve just read everywhere that if insulin is high and there are excess dietary calories - fat storage will likely happen and if there is a deficit of dietary calories - body fat is pretty much locked up and cannot be used (i.e. instead of feeling energetic with keto you go lethargic and feel bad).

(Bacon is a many-splendoured thing) #26

I believe this is so, because if I understand correctly, the glucose in food not needed by muscles or by organs that can’t metabolize fat/ketones gets converted in the liver to fatty acids, transported to the fat cells, and then stored as triglycerides. If I’ve got it right, and this is how glucose get stored as fat, then excess dietary fat that doesn’t get metabolized anywhere could be stored in the fat cells.

#27

Thanks @PaulL - let me recap what you said to make sure I have it right – glucose gets converted to fatty acids in the liver prior to being transported by the blood to the fat cells where it is stored as triglycerides. Excess dietary fat is already in that form in the blood and gets stored by the same mechanism?

Am I correct to assume that the fat cells are only able to convert and store the fatty acids in the presence of elevated insulin?

By the way, you could totally make up an explanation and I’d buy it if it sounded “truthy”!

(Running from stupidity) #28

Never listen to Joel Kahn, then…

(Bacon is a many-splendoured thing) #29

Not precisely; however, I believe your statement would be accurate if you were to strike the word “elevated.”

My logic runs as follows: First, we know that in the total absence of insulin—such as the situation of Type I diabetics—people cannot maintain weight and will actually starve to death. So obviously, the body needs some insulin.

Second, when insulin fluctuates between what used to be considered normal levels—such as when we eat a low-carb, high-fat diet, for example—the adipose tissue is constantly storing and releasing fatty acids. The idea is that the fat cells store energy as we consume it, so as to be able to release it when there is no energy being consumed (for example, during the nightly fast, or when we fast for some other reason).

Third, elevated insulin prevents the release of the fatty acids when energy intake drops (which is part of the reason that fat people tend to feel hungry all the time). Fat cells need insulin to be below a certain level in order to let the fatty acids back out into the bloodstream.

So I would say that the fat cells need a certain minimum level of insulin in order to perform their normal function, but that insulin above a certain maximum (from a high-carb diet, for example) bollixes the system up.

As for “truthiness”: in the words of Ronald Reagan, “Trust, but verify.”

(Running from stupidity) #30

Aye. My thinking as well, primitive as it is.

#31

@PaulL and @juice – this discussion helped me recall the following article, which I think really explains why elevated insulin really drives obesity

(Eric - The patient needs to be patient!) #32

Yup sounds like me without the initial control, if you get my meaning. ::wink::wink:

(Running from stupidity) #33

Here’s a link to the full article - sci-hub.se/10.1001/jamainternmed.2018.2933

(Bacon is a many-splendoured thing) #34

I’m sorry, translation please? :grinning:

(Running from stupidity) #35

Terror more than control :slight_smile:

#36

Full disclosure, I have just started keto (while doing 16:8 IF) and I do tend to be “more liberal” at dinner. Does that mean I ain’t on keto anymore. I had my urine tested for ketone bodies (which indicates ketosis; I am a chemist) and found that I am already on ketosis. Has my being liberal with carbs reversed the benefits of ketosis?

I’m sorry Bansaw if I’m not much help.