I learned a scary thing about fat cells in Animal Nutrition class
I wasn't going to post this because it's fairly depressing, but I'm really curious to see if anyone has heard about this before.
We were talking about puppy food formulations in Animal Nutrition class last week, and my professor started discussing the issue of young animals who become overweight. He said (and I'd heard this before) that animals/humans who are overweight/obese when they're young never get rid of their fat cells. Once you've got 'em, you've got 'em. Like I said, I knew that. But then he said that even if the animal/human loses weight as an adult, those fat cells continue to "request" fat to fill them up. Apparently, they don't like being empty and/or filled with water. And this, he said, often contributes to the difficulties of maintaining a weight loss -- our fat cells actually send messages to our brain asking for...well...FAT, I guess.
Have you heard this? It's not that I doubt the man -- in my opinion he's an absolute genius considering all the stuff he knows about everything animal-related. It's more that I'm...ah...terrified that he's right!
I always heard that you still have the same physical number of fat cells, but they SHRINK in size...so how could they NOT be full? That is where I am confused, since they are smaller they wouldnt *want* as much fat to keep themselves "full"???
I always heard that you still have the same physical number of fat cells, but they SHRINK in size...so how could they NOT be full? That is where I am confused, since they are smaller they wouldnt *want* as much fat to keep themselves "full"???
Yeah, good point. But maybe they don't LIKE to be shrunken? I dunno. Evil little dudes though, huh? The idea that my own fat cells may be actively seeking to get big again is somewhat frightening.
Kate -- I think he's talking about the metabolic and hormonal signals that our bodies send out after weight loss. My understanding that the main culprit is leptin ... and yep, it slows our metabolisms down in an attempt to have us regain the fat. I went to a lecture a year ago and wrote about it here: Some Answers About Genes, Environment, Obesity, and Maintenance and I'm guessing this is the same sort of stuff that your prof is talking about.
But the effect is not permanent. It seems the body can reset its metabolic thermostat upward, to put on weight, but never downward, Rosenbaum said. This explains why 85 percent of people who lose weight eventually put it back on.
"People who sustain weight loss for extended periods of time are extremely metabolically efficient," Rosenbaum said. For years after a diet their bodies struggles to hang on to fat, expending less energy than before.
I've been living this lifestyle for 4 1/2 years now (3 1/2 at goal) and have absolutely no doubt that my body would love to get fat again and that in many ways it's working against my goal of maintaining a normal weight. I believe that my body gives off biochemical signals for me to eat more - which is why I'm hungry so often yet have to continue to restrict calories - and I know my metabolism is slower than that of never obese women my age and size (my body attempting to hoard fat). If I have a setpoint, it's still around 250 pounds.
Sure it's depressing but so what? I simply eat with my head, not my stomach. I recognize that my body sends me faulty cues to eat and fails to send me signals that I'm full. I'm the complete opposite of an intuitive eater: I weigh and measure, journal, plan, and eat by the clock. My appetite is defective -- and I deal with it. Obesity is a condition that I manage and I have no expectations of ever being cured.
Sure, it sucks but we're intelligent enough to outwit nature!
I always heard that you still have the same physical number of fat cells, but they SHRINK in size...so how could they NOT be full? That is where I am confused, since they are smaller they wouldnt *want* as much fat to keep themselves "full"???
The cells are empty of their fat stores (fat is actually stored in liquid form and looks like Crisco oil) but the cellular structure (walls etc) remains behind and never disappears. I imagine that it's nature's system of dealing with feast and famine - a readily available storage system for excess calories.
Sigh. I'm afraid this is all so true. I fought and fought to get the weight off, and put it back on sooo easily - didn't even that much more. For a time my little fat cells must have been sitting around high-fiving one another. They've been worried lately though, the supply line is drying up.
Meg - insightful comment as usual! I also thought about if the guy would mean the hormones that slosh around inside our brains.
Because IMO women are dealing with hormonal stuff ALL the time. Like Meg says, if you have identified the issue, at least you can deal with it.
Kate, if you think about it in that way, why be depressed about it ???
In my personal experience hormonal signals go haywire and can go haywire all the time in lots of people, including me. And this is not a stationary condition.
To my understanding the medics have observed that the brain-body connection works both ways. Not only do they see a change in the body after a change in hormones and brain functioning, but they have also observed that body excercises, like meditation, causes changes in the way that the brain functions. On a less esoteric level, the amount of insuline thatyou have is also not steady, but dependant on the kind of food you ate. So with all these hormones changing levels all the time, why would this leptin be steady and ever-unchanging ?
IMO there is more doctors do NOT know then know about weight and weightloss and mind-body issues in general, and you have a chance that what the professor is telling is a small part of a long and compicated story.
Bottomline- don't let this stuff get you down. Maybe your fatcells in your case are an exception and will stop asking for fat after 5 years. Who knows?
I did hear something about the NUMBER of fat cells being set by a certain age. And since fat cells produce leptin (am I right here Meg?) then I suppose we're going to have increased leptin levels and therefore increased appetite, but we got obese by ignoring our leptin/insulin/appetite regulaing hormones so we can stay thin by ignoring them too!
My first impression of this topic was "Hey, that's not fair!" But, as has been said here any number of times, that's the hand I've been dealt. My healthy weight battle is my own, unique.
I have a genetic build that I have to work around. I have body image issues that I have to work around. I work shift. I have economic issues. Some people can lose on 1800 cals, I can't .... None of this might be fair, but it is my lot.
Having said all that .... I think that information is an extremely valuable tool. Being armed with every bit of knowledge about exercise, food, nutrition, our own bodies, physiology .... better prepares us for our own distinct fitness journey.
If you don't feed your fat cells they can't grow back to their former glory. Are fat cells "immortal" or do they eventually die and get replaced?
Anyway, even if you do get rid of them, your body will replace them if you over eat again.
Robert, it is my understanding that if you get rid of your fat cells..i.e. liposuction, you would grow more, your body wont "replace them" what happens is that the leftover ones you have would just GROW in size!...that is my understanding at least...someone else have ideas on this?
Anyway, even if you do get rid of them, your body will replace them if you over eat again.
Nope...
Quote:
Originally Posted by GonnaLooseitagain
Robert, it is my understanding that if you get rid of your fat cells..i.e. liposuction, you wouldn't grow more, your body wont "replace them" what happens is that the leftover ones you have would just GROW in size!...that is my understanding at least...someone else have ideas on this?
That's been my understanding as well...check out this link (you might want to scroll down to "Fat Location & Distribution".
Quote:
Fat percentage and placement depends upon hormones such as insulin, testosterone and estrogen. The one thing about fat is that once puberty is over - what fat you have is what fat you get forever. Your fat cells only multiply if you reach 200% of your body weight. Which is a rare occurrence indeed and only seen in severe obesity cases. However, fat cells can expand enormously.
In a nutshell, if you have fat cells removed via liposuction, and don't change your eating/exercise habits, your body will squirrel those excess calories away in the fat cells that you still have (often with less-than-pleasing results).
Think of fat cells like balloons, and the fat stored within like the helium or air in the balloons. By losing weight, it's just like letting the air out of some of those balloons, so they become flat - but they can be blown up again...
Yes, it looks like there is very little turnover in adipocytes. They can,however, be induced to die.
I did a search on apoptosis (programmed cell death) and adipocytes and found an interesting review article:
Quote:
Targeted apoptosis of adipocytes
De novo differentiation of adipocytes from precursor cells is virtually irreversible. One of the reasons for the slow or non-existing turnover is the adipocyte's remarkable resistance to apoptosis [21]. The underlying mechanisms for the hardiness of this cell type are not clear, but can be explained in part by the very high Akt/protein kinase B levels in mature adipocytes. Furthermore, the levels of the anti-apoptotic factors Bcl-2 and neuronal apoptosis-inhibitory protein increase during adipogenesis, imparting resistance to cell death [22 and 23]. Caloric restriction leads to reduction of fat mass, but it does not necessarily involve a reduction of the number of fat cells. However, conditions of pathological fat wasting can involve loss of adipocytes through apoptotic mechanisms. For example, apoptotic events were observed in fat tissue of patients with tumor cachexia. Apoptosis was also implicated in the fat remodeling processes associated with highly active antiretroviral therapy in HIV infected patients with lipodystrophy [24, 25, 26 and 27]. Targeted and moderate induction of apoptosis in adipocytes could be an attractive approach to reduce the number of fat cells, particularly when coupled with a reduction of caloric intake to avoid spill over of lipids into other tissues. However, at this time little is known about the apoptotic machinery in adipocytes and thus therapeutic modalities relying on a selective induction of apoptosis within this cell type remain a distant prospect.
That would be pretty neat. Liposuction in a pill.
Taken from:
Quote:
1: Drug Discov Today. 2005 Sep 15;10(18):1219-30.
*
Keynote review: the adipocyte as a drug discovery target.
Nawrocki AR, Scherer PE.
Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA.
The adipocyte has pleiotropic functions beyond the storage of energy in times of nutrient abundance. Considerable efforts in adipocyte biology within the past ten years have emphasized the important role of adipose tissue in processes as diverse as energy metabolism, inflammation and cancer. Adipocytes are able to communicate with the brain and peripheral tissues implementing metabolic signals such as satiety, food intake and energy expenditure. Despite its huge pharmacological potential, only a small number of clinical applications interfere directly with adipocyte physiology. Here, we want to highlight various areas of adipocyte physiology that have not yet been explored pharmacologically and emphasize some of the limitations associated with these pharmacotherapies.
I think anyone who has maintained a large weight loss for six months or more will have discovered that those fat cells want to be fed and plumped up to previous levels.
I learned a scary thing about fat cells in Animal Nutrition class
They've been worried lately though, the supply line is drying up.
