My question is once this procedure has been completed and say the person really got into some heavy cardio and thus were burning a lot of fat would the body be able to burn the fat that was moved to the buttocks or does it not have the associated blood vessels to enable this?
I’m not even sure if that’s how lipids are metabolised, but I assume it’s through the blood.
Hi. I’m not a doctor, but I can opine as a biologist.
The transplanted cells have blood vessels, because all cells need a supply of oxygen to avoid expiring. If they didn’t have a supply of blood, they’d quickly turn necrotic.
When you deplete your short term energy stores, the body converts fat molecules within fat cells into sugar, then shuttles those through the body in the blood stream.
The body doesn’t draw on fat stores within the body in a totally even way, so I don’t know how quickly it would draw from the transplanted cells, but it works presumably still burn fat from these cells when needed.
And the reverse is true as well: when excess sugar is available, the body would generate new fat molecules to fill those cells, and if necessary make new fat cells as well.
Thanks.
I feel a little stupid now, as it’s obvious that it would die if it didn’t have a blood supply.
So when they’re transplanted they’re going to connect some blood vessels. I am not understanding how the cells are still able to know when to turn fat into glucose, but again I’ll assume it’s done through the blood with an enzyme or something.
I think you’ve answered the main question though showing it can use those stores. Much appreciated.
Fat is usually stored in the body in the form of triglycerids. When fat is used, it’s usually not turned into glucose, but rather into fatty acids, that are then released in the blood and reach the cells that need extra energy, where they are used by the mitochondria to power said cells. The signaling that triggers this is in fact done by a bunch of hormones that do indeed circulate in the blood to reach the cells specialized in storing fat, called adipocytes.
Depending of what triggers the transformation of fat into fatty acids( a process called lipolysis), those hormones could be insulin, epinephrin, growth hormone, etc.
What about ketosis? Are ketones a legit way to remove fat?
Yes, ketone bodies are the result of the beta-oxydation of the fatty acids in triglycerides. It’s the way the body breaks down fat into molecules that it can either burn or tranform into other molecules like sugars.
The Atkins and ketogenic diets are legit, but they can be risky and you can harm your body (like your kidneys) without professional guidance. And you can also bounce back to your original weight afterwards, which is something I find fascinating.
I wonder if the bounce back is the body trying to find homeostasis… of sorts. I’ve gone hiking for a week and come back having lost 10 lbs. A month later I’ve gained it back. I know it’s your diet, but gaining it that fast can’t be normal.
Probably at least half of it is water weight, so it might be pretty close to the recommended pound per week
You know, I’ve wondered that myself! It’s mind-blowing to me when people say they’re back at where they started. So I suspect it has to be at the genetic level to keep you at a certain weight. Here’s a talk by Dr. Giles Yeo (neuroendocrinologist) making the case for it. (Main point starts at 5 min mark)
There are some working theories (with some amount, but not enough yet of good science) this has to do with your gut microbiome. Since these bacteria are a critical (and still largely unknown) link in not only our digestion, hormone response, nutrient absorption, and immune/inflammatory response.
In essence, a particular set of gut bacteria are good at breaking down certain types of food in certain quantities, and they’ll tell your body to keep giving that type food and quantity. So unless that’s changed with longer term dietary changes, you’ll return to your previous state because thats what your gut is telling you to eat keeping your original cycle.
Oh wow, interesting, and seems reasonable.
Any links to even mediocre science on this? Or anythung suggestive?
I wouldn’t call it mediocre science, just the area of research needs more attention before its cemented as a complete theory with actionable paths.
Here’s a primer one some of the foundational ideas from the American Society for Microbiology.
Thanks!
Yea, poor choice of words…I was in a rush, haha.
I very much appreciate you were doing an ELI5 answer for this, so forgive my if I’m dissecting this too closely.
Your body uses up all sugar in the blood (glucose), then exhausts short term energy stores including Glycogen in your muscles and liver next. At that point (given enough time and no re-introduction of glucose from eating), doesn’t your body go into Ketosis? So your liver would be taking fat from your body and converting it to Ketones to power your brain and body. I didn’t think Ketones were a sugar.
Alternatively, if you don’t burn through all your body’s glucose, your body can use some glucose and some fat to produce energy when operating with enough oxygen (aerobic).
Do I have that right?
Yes, ketosis happens within a few days of limiting sugar intake.
You’re right, they’re very different molecules. Ketone bodies can be converted into sugars by the enzymes in the liver if your body needs them, but they’re not sugars themselves.
Honestly, I don’t recall the details. What I shared was my best recollection. I think what you said sounds reasonable, but I can’t reliably say.