10 Things to know about Fat

[cmcole]

http://www.fashionmagazine.com/Verve/ShowArticle.aspx?id=338&Parentid=239

http://www.fashionmagazine.com/Images/Head/338_June2005_Header_10ThingsAboutFat.jpg


The real reason your doctor cares about your weight: It’s not only the extra load you carry, but also the extra miles of blood vessels in a big body. According to one source, every pound of fat contains a mile (1.6 kilometres) of blood vessels.

You could have collagen injected to smooth your wrinkles or have your own fat, harvested from, say, your thighs, used for the purpose. Some things to consider: Fat injection is a permanent procedure, while synthetics such as collagen are repeat procedures. The incidence of allergic reactions with fat is virtually nil, but it’s a more serious operation, because the harvesting must be performed under general anaesthetic.
Canadian per capita consumption of oil and fat went up more than 40 per cent from 1992 (48.7 pounds) to 2003 (69 pounds). Sadly, there’s no reason to believe that’s an increase in good fats.
The butter connection, part 1: Human fat is butter yellow and has the solid yet squishy consistency of butter that’s been left out for a couple of hours.
You’ve probably been told that you can change the size of your fat cells but not lose them. This, sadly, is true. Current theories suggest that the body creates new fat cells once the older ones have reached their capacity —thus our unlimited ability to gain weight. However, when you lose weight, the fat cells shrink but don’t disappear.
The most fat you’d want to remove during liposuction is five litres—imagine a large pop bottle’s worth from each thigh, and then some. Extracting more increases the risk of uneven skin texture, falling blood pressure and blood clots.
The butter connection, part 2: You could, technically, really melt pounds away. Like butter, human fat would melt if heated. Of course, there’s no way to use this to your advantage. Sitting in a sauna just won’t cut it.
Obese women are at a greater risk for breast and reproductive cancers, but at a lower risk for osteoporosis. The culprit is excess estrogen, which is produced by fat cells.
Fat is the only cell mass soft enough to come out with suction. This is why liposuction works without sucking out muscles and blood vessels.
The most popular area for liposuction is the thigh, inner and outer. The most common age: in your 30s.By Kat Tancock and Terese Saplys. Special thanks to: Dr. Heidi Engelhardt, assistant professor of zoology, Brandon University (#1); Dr. Wayne Carman, Cosmetic Surgery Institute, Toronto (#2, 3, 6, 9, 10); Dr. Elizabeth Johnston, director and professor, School of Nutrition and Dietetics, Acadia University (#5, 7, 8); and Statistics Canada (#4).

[Niobe]

I've always wondered about that "fat cells are forever" thing ... to me it doesn't make sense. Why would your body maintain those structures instead of breaking them down and re-using the materials? Can anyone with more scientific knowledge say if that's an accurate claim?

[cmcole]

I wondered that same thing, as well. Is it perhaps that, for some reason, the "walls" of fat cells are more resistant (hence, their ability to expand) to breakdown?

I, too, would like scientific explanations.

[psivamp]

I have heard that when a fat cell is called upon by the body to release it's contents that the cell wall ruptures to release it's triglycerides into circulation (kind of gross) i don't if this is total fact or not. One thing i do know is that large consumption of fat is leading to less fat on my body. weight 186 #'s mid march to 167 in mid may

[Gabriel Guzman]

I've always wondered about that "fat cells are forever" thing ... to me it doesn't make sense. Why would your body maintain those structures instead of breaking them down and re-using the materials? Can anyone with more scientific knowledge say if that's an accurate claim?

While the lifespan of fat cells is not infinite, they do seem to live quite a long time. The best estimates obtained from human data indicate that the triglyceride and cell turnover is indeed slow. The half-life of triglycerides and cells is of about 6-9 months. This is 'half-life', which means the time required for 'half' of whatever you're measuring to disapear, so that gives you an idea of how long do fat cells actually live.

I does make sense for the body to hang on to its fat cells as they're the only fat deposits available to store energy when needed. The problem is to 'overstock' and then not use the surplus energy in store.

Despite the long lifespan of fat cells, that doesn't mean they're there forever. There is, in fact, cell death (also known as 'apoptosis', although I'm more comfortable with apoptosis meaning 'programmed' cell death). Apoptosis is an important mechanism to keep tissue homeostasis by replacing old or damaged cells with new ones. In the case of fat cells, the issue is still debated but there is evidence of this important mechanism to keep fat cell turnover. To see the importance of apopotosis, think of some kind of tumor cells in which their apoptotic program is altered which in turn prevents cells from diying when they should. Some people think that inducing apopotosis in fat cells provides a way to fight obesity by making fat cells disapear. Some studies suggest that compounds like conjugated linoleic acid induce apoptosis in fat cells (at least in mice), but it didn't come without the price of becoming insulin resistant in the process.

I wondered that same thing, as well. Is it perhaps that, for some reason, the "walls" of fat cells are more resistant (hence, their ability to expand) to breakdown?

I, too, would like scientific explanations.

The general composition of the cell membrane (or plasma membrane) of fat cells is similar to other cells. The differences are in lipid composition, proteins that populate the membrane (which contribute to the specialization of particular cell types). For example, fat cells and red blod cells both have a plasma membrane made of lipid fashioned as a lipid double-layer. Both types of cells contain proteins in their membrane, some of them are the same, some other are specific for fat cells or red blood cells but the general structural arrangement is similar and both very 'flexible'. The main difference between the cells is that fat cells have the capcity (and machinery) to make triglycerides inside and store them. If a red blood cells was given a nucleous with all the genes of a fat cell (mature red blood cells don't have a nucleus), it would probably end up storing fat as well. The precursors of fat cells, called fibroblasts, differentiate into fat cells upon stimulation with the right stimuli (insulin and other growth factors), and then they start 'behaving' as fat cells, expressing specific fat cell genes but the 'backbone' structure of the membrane is that of a fibroblast. In fact, if the right stimuli are provided, fibroblast can become other types of cells as well.

I have heard that when a fat cell is called upon by the body to release it's contents...


That is roughly true. Stimuli such as fasting (which causes an elevation of glucagon, among other hormones), triggers mechanisms in the fat cells designed to release triglycerides that can be used for fuel by other tissues, such as muscles and the brain, for example. However, fat cells don't release 'their contents', only triglycerides. As perfectly pluripotential cells, they have nucleus and other organelles that remain inside the cell.


...that the cell wall ruptures to release it's triglycerides into circulation (kind of gross) i don't if this is total fact or not.

That, I'm afraid, is a misconception. There is no membrane rupture, particularly in the case of triglycerides, which are 'fat soluble' and have the potential to just diffuse through the cell membrane (also made of quite a bit of lipid) on their own, unaided. However, triglyceride release as well as triglyceride internalization are both controlled mechanisms and cells are equiped with specific proteins in their membranes called transporters that get that job done. Cells have a wide array of transporters in their cells that are called upon depending on the stimulus. For example, when glucose needs to enter the cells (fat cells included), glucose transporters are called upon to 'translocate' into the membrane so they can perform their 'glucose uptake' job. Fatty acids is actually what is transported out of the fat cell into the circulation and then taken up by other tissues (a triglyceride molecule is in fact three fatty acids linked together by a molecule of glycerol). Since fatty acids can't travel on their own through the bloodstream (which is basically water-based and fat doesn't mix with water), they're bound to albumin, which carries them and deliver them where they're needed. There is nothing gross about it, really... just an amazing mechanism that Nature has came up to transport something that doesn't mix with water through a water-based medium, the blood, to nurture other tissues that need energy.

One thing i do know is that large consumption of fat is leading to less fat on my body. weight 186 #'s mid march to 167 in mid may.

And this is the 'fat of the matter'. For that fat to enter your fat cells to increase their size and your waist line, the proper stimulus must be there... insulin, and enough of it to keep fat internalization always on.

[Niobe]

Gabriel, thanks so much for such an informational response. :)

[Gabriel Guzman]

You're very welcome!

[cmcole]

You are an incredible wealth of knowledge, or at least know where to dig it up without too much time elapsing.