Questions about weight loss/gain and fat cells

Bump off my ever growing belly.

I've heard you don't gain or lose new fat cells, your current ones just get bigger or smaller. The same thing is true of muscle cells.

I don't really know but I thought I'd bump your thread for you... wikipedia probably knows the answer.

But I don't really understand what happens with liposuction. I think they actually remove the fat cells, and they grow back afterwards, but I'm not sure how it's regulated in your body.

People are born with a finite number of fat cells. Some have more/less than others. It is one of the factors that account for the differences in people's weight and size. Fat cells shrink and/or increase in size depending on diet and exercise etc...

What that one said.

Also, that 'cottage cheese' look is simply overstuffed fat cells pushing against the skin.

In muscle hypertrophy you are increasing the # of contractile proteins in the cell.

Muscle Hyperplasia, the increase in # of actual muscle cells, can happen artificially through the use of IGF...Insulin-like Growth Factor.

Does Muscle Hyperplasia occur naturally? Animal studies have shown that it does. Human studies are scarce but at least one study has shown it to occur in some individuals.

So what does this mean? Common sense would dictate that those who naturally have a large muscular appearance and who become elite strength athletes or bodybuilders likely are born with slightly more skeletal muscle cells, more specifically the muscle fiber type more responsive to growth and strength output....the type IIb fibers. Interestingly bodybuilders have much more type IIa fibers due to the exaustive nature of their training. On the flipside, endurance athletes at the top are likely born with slightly fewer skeletal muscle cells specifically fewer Type IIb fibers. Endurance athlete still experience muscle hypertrophy but typically in the Type I fibers, which don't have near the growth response as Type II fibers. The very obese are likely born with a slightly higher number of fat cells to begin with thus increasing their chances of becoming obese.

Just some thoughts to chew on...

Alan

So what happens when you get liposuction? The fat cells are removed, right? Do they grow back?

You can manipulate fat cells through diet. not all fat is the same. The idea that the number of fat cells per se is always the same is not true. google "set point theory"... you might understand why people always tend to look the same before and after weight loss/weight gain

You can shrink the fat cells but you can never lose them which makes it easier to gain the fat back.

You grow more fat cells during 4 points in your life. After you are fully grown, you cannot grow new fat cells. This would lead me to believe that the fat cells lost in liposuction would not grow back, but I have no experience with the matter to back that up. These cells can, however, increase or decrease in size. The set point theory basically says that when a person loses or gains weight, their body will often fight to resist the change, by slowing the metabolism and in other ways. The person must maintain the new weight from 1.5-3 years for the body to reset. New studies show that certain genes determine how resistant a person's body is to weight change. A person with "Thrifty" genes will have a harder time losing weight.

Thanks. This is what I wasnting to read about, set point theory and fat cell theory. Even though much is debated about these, either way it really shows that lifestyle changes for extended periods of time are crucial for permanent weight loss.

Fat Boy in Denial wrote:

You can shrink the fat cells but you can never lose them

With lipo, you can.

For what it's worth, this (see below) was in my newsletter from Jason Karp this morning. I know, I know, he gets a bad rap. But, it still adds to this discussion.

Fat Burning Zone

People often assume that low-intensity exercise is best for burning fat. During exercise at a very low intensity (e.g., walking), fat does account for most of the energy expenditure, while at a moderate intensity (e.g., 80% maximum heart rate or about 70-75% VO2max), fat accounts for only about half of the energy used. While you use both fat and carbohydrates for energy during exercise, these two fuels provide that energy on a sliding scale-as you increase your intensity up to your lactate threshold, the contribution from fat decreases while the contribution from carbohydrates increases. When you exercise at an intensity above your lactate threshold, you use only carbohydrates. While there is only a minimal amount of fat used when exercising just below your lactate threshold, the number of calories used per minute and the total number of calories expended are much greater than when exercising at a lower intensity, so the amount of fat used is also greater. What matters is the rate of energy expenditure, rather than simply the percentage of energy expenditure derived from fat. Since you use only carbohydrates when exercising at a high intensity, does that mean that if you run fast or take a high-intensity Spinning class, you won't get rid of that flabby belly? Of course not.

Despite what most people think, you don't have to use fat during exercise to lose fat from your waistline. After all, have you ever seen a fat sprinter? Sprinters primarily train anaerobically, never using fat during their workouts. Carbohydrates are actually the muscles' preferred fuel during exercise. The little amount of fat that is used in combination with carbohydrates during exercise below the lactate threshold is in the form of intramuscular triglycerides-tiny droplets of fat within your muscles. Your adipose fat (the fat on your waistline and thighs) is burned during the hours before and after your workout. Since fat is oxidized inside your muscles' mitochondria, it is more efficient to use fat during exercise that is physically closer to the mitochondria, when you need to regenerate ATP quickly for muscle contraction. To use adipose fat, it has to be transported to the mitochondria where it can be oxidized.

To become a better fat burning machine, you must enhance the metabolic profile of the muscles. Endurance training enhances fat oxidation by increasing skeletal muscle mitochondrial content and cellular respiratory capacity, allowing for a greater use of fat and the sparing of muscle glycogen. This steering in fuel use to a greater reliance on fat at the same exercise intensity is one of the hallmark adaptations to endurance training. Since a metabolic priority of recovering muscle is to replenish glycogen stores, the way to not gain excess fat is to constantly use your glycogen stores during exercise so that the carbohydrates you ingest will be used to replenish the glycogen stores rather than be stored as fat. If your glycogen stores are already full, as they are in most of the population that doesn't exercise, any extra calories you consume are stored as fat. So when people say that sugar makes you fat, that's only true if that sugar is not used to replace your muscle glycogen stores.