Hacking Fasting Post-WLS

(Meeping up the Science!) #1

I’ve been having many conversations with @Daisy about fasting post-WLS, it’s clear that it is more difficult to fast, even fully fat adapted, than many would imagine. After receiving an unsatisfactory response from other sources, I set myself to research.

Currently, my theory is that we are oversecreting ghrelin post-operatively compared to our normal state, and that our systems are now hypersensitive to it. Ghrelin normally inhibits nausea and encourages gastric motility after food is in the stomach. When you fast, ghrelin levels typically skyrocket. I suspect something is involved in the ghrelin expression of the neurons in the raphe nuclei or the arcuate nucleus. Nausea is also neurological as well as appetite, and my theory is that in the medulla oblongata is where things might go awry fasting. Maybe? Any observations would be spiffy. :wink:

If anyone has any observations that might be useful.

#2

WE need to do some n=1s don’t we? As many as poss.

(Bacon for the Win) #3

I am 12 years post-op, and I can tell my responses are wacked. My hunger is different, really can’t explain, and there really is no satiety. Usually by the time I feel full I’ve eaten more than I should. Full is more of a physical ache than a signal that I’ve had enough. That’s why it’s important to me to log my food. Other wise I have no brakes. When I eat a lot of fat in one sitting (such as the whole avocado yesterday) it tends to make me nauseous.

(Meeping up the Science!) #4

Which surgery did you have? Did you have the avocado and other food, or just an avocado? I think we still need moderate to high protein post-op for a few reasons. I have some theories, but I haven’t had time to research.

I also don’t have any fullness, actually, so I also measure everything, however I have a sleeve. Now I can eyeball well, usually. I don’t have fat issues, but I can no longer eat chicken breasts at all. Thankfully that I will take. It’s actually easier by a significant degree for me to eat fattier foods than dry/low fat ones.

For sleeve gastrectomy patients, I am 99% sure it’s an abundance of ghrelin that is secreted post-fasting which is causing the symptoms. I still need to do more research. I’m also trying to persuade someone to do a serum ghrelin test on me after 18 fasting hours.

#5

Donna, are you saying that the surgery “broke” the “link” between insulin and ghrelin function?

When I snack during the day, I notice I induce hunger. For example, if I go to Costco and try some of their freebie snacks, I get hungry. When I return home, I want to eat. If I refuse the snacks, I’m not hungry until night time. I believe this is because I keep insulin depressed, which then helps to depress activity of other hormones, like ghrelin. I dunno. It’s a guess.

Are you saying that the surgery does not allow you to manipulate insulin levels, and therefore less control with other related hormones? Or something else going on?

(Meeping up the Science!) #6

So with the sleeve, we see a significant reduction in serum ghrelin that is permanent. What I think happens is that fasting triggers the “backup” ghrelin cells (the pancreas and intestines also can create it) to spike the levels. We are sensitive to the lower level post-op because our levels are so low, and the huge amount of ghrelin causes nausea. While I don’t think or know if there ghrelin resistance, there is leptin resistance. So, there may also be ghrelin tolerance/hypersensitivity. Whenever someone fasts ghrelin is high. Typically in the obese, ghrelin levels are lower.

I suspect the nausea is neurological - ghrelin and leptin have many brain receptors. Much nausea actually is neurological rather than gastrointestinal. If it’s neurological it’s 99% likely to be the ghrelin or hunger hormones balance. After I eliminate ghrelin as a possibility I will go down the list.

I don’t know that it has anything to do with insulin at all. I think that people unfamiliar with ghrelin are mistaking it for hypoglycemia. I’d be more inclined towards that if it was the bypass. Sleevers typically are not hypoglycemic, whereas they more often get it. And it’s sleevers having the fasting issues.

It’s easy enough to test as causing the stomach to expand enough so food starts entering the pylorus will cause ghrelin production to cease. The trick is keeping the injested stuff it high volume, low energy, so basically nothing that disrupts autophagy. Possibly bullion broth with a shot of fat? I think 1/2 an avocado would also do it.

It may also be vagal tone, as the vagus is affected by surgery in partially unknown ways despite being left intact.

This is all highly speculative, of course. I’m still researching, but can’t really do more until my exam is done in two weeks.

(Bacon for the Win) #7

I had Roux n Y. That was pretty much the standard in 2005. Just an aside, I now work at the hospital where my surgeon did his residency. The avocado was wrapped in bacon with an egg in the middle. A friend pt it on my FB wall and I decided to make it. It was not pretty but I was out of time to make something else, so I ate it. Usually I eat half an avocado with no problem. I know I need to watch my protein intake. The DEXA done a year ago shows less LBM than a few years ago.

I am sort of the same way, but I wonder if it’s just a mental thing. If I eat the snacks there I want more to eat, period. If I don’t eat them then I’m fine. Mental or a true physical responce I have no idea.

#8

No. For me it’s not a mental thing. I get glucose fluctuations. Which tells me insulin has been changing levels. Since there is discussion in literature that insulin influences the dynamics of ghrelin and leptin, it causes me to wonder how avoidance of snacking helps maintain the hunger pangs depressed. For me, eating keto removes need for snacking, as I’m not hungry. But, if I eat a snack, because I was offered food, it starts trouble for me. So, I have to decline snacks.