The no "BS" FAT LOSS thread!!!

Pam3

thanks great information:flowerforyou:

glassgallm

bump

LesleeAH

bump. Great info, looking forward to more!

ninerbuff

By Dan Gwartney, M.D.



The Science on Fat Loss: Lipolysis and Fat Burning



It is peak time for making New Year’s resolutions. As it has been every year, losing weight sits on or near the top of the list for the majority of people. Given the economic conditions, it may have taken a back seat to financial goals (save more, pay off debt, eat at home, etc.)— but it remains a perennial favorite.

Of course, health clubs and weight loss centers depend upon this annual parade of lemming-like couch potatoes, with the month of January accounting for nearly 50 percent of new membership enrollments in established clubs.1 Invariably, the advice of eat fewer calories, perform cardiovascular exercise to burn fat, and lift weights to build muscle (and bone if you are a woman) is given in an office furnished with a Steelcase® desk, flat screen monitor, and those blue fabric chairs.

The charming early-20s trainer, upbeat music, as well as the digital flashiness and iPod® compatibility of the machines are designed to motivate and inspire members to meet their goals. Unfortunately, fat loss does not occur because one wishes it will. Fat loss is the result of a series of chemical reactions.



Fat Storage

Before talking about fat loss, it may help to understand fat storage. Ask most people where fat is stored and they will grab the skin around the navel as though there is a Tupperware® container of Crisco® belted around the belly. In part, this is true at the cellular level. Body fat is thought of by many as being unsightly lumps and bumps; in the U.S., this often lowers one’s social standing. To the body, fat is wealth, as it represents energy reserves that will allow a person to withstand days to months of famine; it also allows for long periods of low-to-moderate activity between meals. To the mitochondria (the power factories of living tissue), stored fat is like cash in the bank.

Unlike wealth, the display of a fortune in body fat is neither envied nor advantageous as is the opulence of financial wealth. Let’s face reality; people turn green with envy when they see a multi-millionaire being chauffeured in a Maybach 62 S. Conversely, very few in the U.S. demonstrated the same response when they see the body of a person with a 10-year savings account of adipose (fat). A million calories of stored fat is not as wonderful as a million dollars.

Of course, millionaires don’t carry their cash on them in bundles of $10 bills. Ironically, one gram of fat has nine calories and a million calories of fat would weigh 244 pounds. A million dollars in $10 bills (as close as one can get to a $9 bill) would weigh a little more than 220; coincidentally, a $10 bill also weighs a gram.

Despite the abhorrence most have towards morbid obesity, and the epidemic of increased deaths and disease that accompany this degree of fat accumulation, the human body is still designed to absorb and store as many calories as possible. This seems inappropriate in today’s society here in the U.S., but traveling to many parts of the world will confirm that starvation and famine remain common. Even in the venerable U.S., food rationing and soup kitchens were a national way of life 60-80 years ago. Global genetic adaptation (evolution) to discourage rather than promote the storage of fat is unlikely to occur for many, many generations, if ever.

Body fat is primarily stored in specialized cells called white adipose tissue (WAT).2 Folklore suggested that people are born with a set number of fat cells and individuals are stuck with those cells for life; the same was also said of brain cells. Medical science has proven this is not true. Fat cells arise from a self-replenishing pool of precursor stem cells— the same precursor cells that can also turn into skeletal muscle.3 Contrary to another folktale, even though muscle and fat arise from the same pre-cursor, muscle does not and cannot turn into fat when a person stops exercising. Instead, muscle atrophies (shrinks or wastes away) if a person stops training and fat stores increase due to the decrease in physical activity, often in the setting of overeating.

Calories are consumed in the diet. The focus used to be on dietary fat as being the source of body fat. It made sense to the general public and marketing agencies across the nation; if fat is being stored, then it must come from fat that is being consumed. Then the Atkins Diet diverted blame onto carbohydrates and their wicked habit of raising insulin, which in turn promoted fat storage. Now, the public is back to not knowing what to think.

Breaking it Down

Fat is a generic term— it can be a relative comparison; refer to either tri-acyl-glycerides or specific fatty acids; or if spelled P-H-A-T describe a particularly attractive woman. For the purposes of this article, the term fat refers to tri-acyl-glycerides (TAG), a chemical class of molecules defined as three fatty acids bonded to a common glycerol atom. To make it an easy visual, hold your hand out and extend only three fingers (pointer, middle, and ring fingers). The hand is glycerol and each finger represents a fatty acid. There are many different fatty acids in the diet and in stored fat. Many are familiar with the terms saturated and unsaturated fat (fatty acids). Omega-3 fatty acids are a subset of unsaturated fatty acids, as is oleic acid— a monounsaturated fat rich in olive oil. The differentiation between saturated and unsaturated is not important for the purposes of this discussion.

When dietary fat is consumed in a meal, it is commonly in the form of a TAG. TAG will form big globules in the watery environment of the stomach and intestines; drop some cooking oil into a bowl of water for a demonstration. To break up these globules, the gallbladder secretes bile acids, which make the TAG form smaller globules so that enzymes can attack. Lipases are enzymes that break down TAG to 2-monoglycerol and fatty acids.4 These digested fragments are taken up or absorbed in the small intestine and re-formed into TAG, packaged with cholesterol in lipoproteins, and transported through lymphatic ducts before entering the bloodstream. Some free fatty acids and TAG directly enter the bloodstream and can be taken up by exercising muscle and other active tissue (e.g., heart) for energy or to be stored in those tissues as an immediate source of long-term energy.5,6

TAG are packaged in the liver for transport to adipocytes (fat cells), where they are again broken down into fatty acids by a fat-cell bound enzyme called lipoprotein lipase (LPL).6 High concentrations of insulin increase the number of LPL in fat cells, increasing fat uptake for storage rather than as energy for muscle, heart, etc.6,7 The fatty acids released by LPL can circulate in the blood or be taken up by the fat cell and converted once again into TAG which is stored in a fat globule in the fat cell. If a person eats a calorie-appropriate diet, the process is well-balanced, providing for immediate and long-term energy needs while avoiding excess body fat accumulation.

That may be everything and more than most wish to know about how fat gets from the lips to the hips. What is the primary concern for most is how to shed the saddlebags.



Losing It

Fat loss occurs when the fat cells are stimulated by certain hormones (growth hormone, glucagon, ACTH, etc).8 A common pathway stimulates the activation of several enzymes, as well as “opening doors” in the fat globule so the enzymes can deconstruct the TAG into glycerol and free fatty acids.

For some time, the scientific model held that a single enzyme was primarily responsible for most of fat breakdown and release. Further, the thought was that the freed fatty acids either fled the bondages of TAG incarceration or were re-incorporated into TAG that was confined behind the prison-like membrane of the intracellular fat globule (possibly charged with additional time for a failed escape attempt).

However— and this will probably only thrill the biology geeks for the most part— a fuller understanding of the processes relating to the release and breakdown of TAG stored in the intracellular fat globule of the adipocyte (fat cell) has recently been gained through ultra-fine research.9 Scientists have determined that stored fat is brought to the surface of the fat globule inside the cell when gateway proteins are phosphorylated (turned on).10 There, a newly-discovered/understood enzyme call desnutrin/ATGL breaks off one of the three glycerol-bonded fatty acids.11

Think back to holding three fingers from your hand to demonstrate what a TAG looks like; desnutrin/ATGL just breaks off the pointer finger. The TAG becomes DAG when it loses one fatty acid. DAG is attacked by a second enzyme called hormone-sensitive lipase (HSL) that only breaks off the ring finger; after that there is another enzyme that takes care of the remaining fat fragment called a MAG— tearing off the “middle finger” fatty acid.9

The three free fatty acids and the glycerol molecule that have been created by breaking apart TAG can either enter the circulating bloodstream or be converted back into fat. Yet, researchers have now found that the free fatty acids can also be used by the fat cell itself for energy. In fact, when lipolysis (fat breakdown) is turned on, the fat cell’s energy factories appear to be pushed into high gear, burning fat for energy at a higher rate.12,13

It was long believed that fat cells were metabolically quiet, but the last decade has shown that they produce hormones that affect the metabolism and appetite, as well as being a place where calorie burning occurs. This agrees with recent observations that it is healthier to have a large number of small fat cells rather than relatively few fat cells that are large.14 After all, it takes more to feed a hundred hungry children (small fat cells) than a couple of sumo-wrestlers (large fat cells).

Not surprisingly, fat cells of obese people absorb fatty acids more readily than lean people and do not burn fatty acids for calories, preferring to store the energy as fat.15 It is beneficial to the body that the fat cells do use up fatty acids as they are being released to some degree as an overload of free fatty acids in the system causes a condition known as insulin resistance, sometimes called pre-diabetes.16,17

There are two relative states that directly affect the fat cell’s willingness to release and break down fat. When the body is fasted (has not eaten for many hours), certain hormones are elevated, promoting a lipolytic (fat breakdown) response to the fat-losing hormones and neurotransmitters, the most important being norepinephrine— an adrenalin-like chemical released from nerve endings.18 When the body is fasted, the concentration of glucocorticoids is elevated, which upregulates (similar to stimulating or promoting) the production of desnutrin/ATGL.19 In the fed state, insulin concentrations are high, which activates the enzyme that turns off the fat-loss signal generated by the adrenaline-like biochemicals and drugs.18 There are a number of other hormones and signaling molecules that affect the fat cell’s preference to store or break down stored fat.



Prostaglandins

One other recent discovery (biology geek time again) that revealed another way fat cells regulate fat storage/breakdown was reported. Prostaglandins are signaling molecules that communicate only with surrounding cells, or sometimes even just the originating cell itself. They are the biochemical equivalent to a whisper, and as all know, the most interesting information is usually told in whispers.

The fat cell has a relatively unique enzyme that generates a prostaglandin called PGE2. In the fat cell, PGE2 slows down fat loss by degrading cAMP, a chemical messenger signal that is produced when fat loss hormones/chemicals attach onto receptors located on the fat cell.12 These fat loss hormones and drugs that circulate through the bloodstream cannot enter or turn on the fat loss mechanisms of the fat cell. That happens when cAMP is generated, carrying the fat loss message to various enzymes and proteins like an office gofer passing out memos. If the gofer is fired (or cAMP degraded), the office (or fat cell) has no direction and just sits there biding its time. If there is a cell-level version of solitaire, this is when the fat cell would be playing. PGE2 degrades cAMP (fires the gofer), slowing down fat loss.12 The enzyme that produces PGE2 (called AdPLA) is turned on by insulin which is highest in the fed state.12

Pretty amazing— the interaction between so many regulating processes. When one considers all the various hormones, drugs, enzymes, etc., involved in fat storage/breakdown, it becomes clear why one drug could never circumvent all the regulatory pathways.

This article presents a lot of science and describes (only superficially) how complex fat storage/breakdown is within fat cells. However, as the Chinese philosopher Sun Tzu wrote, “If you know the enemy and know yourself, you need not fear the result of a hundred battles.” [paraphrased] People know how much they eat, drink, exercise, and sleep; knowing how the body responds, especially a part of the body that many struggle to control, will help win the fat loss battle.



References:

2009 Jan 6. Available at http://archives.chicagotribune.com/2009/jan/06/business/chi-tue-consumerland-0106-jan06, accessed Nov 15, 2009.

2. Voshol PJ, Rensen PC, et al. Effect of plasma triglyceride metabolism on lipid storage in adipose tissue: studies using genetically engineered mouse models. Biochim Biophys Acta, 2009 Jun;1791(6):479-85.

3. Singh R, Artaza JN, et al. Androgens stimulate myogenic differentiation and inhibit adipogenesis in C3H 10T1/2 pluripotent cells through an androgen receptor-mediated pathway. Endocrinology, 2003 Nov;144(11):5081-8.

4. Armand M. Lipases and lipolysis in the human digestive tract: where do we stand? Curr Opin Clin Nutr Metab Care, 2007 Mar;10(2):156-64.

5. Koonen DP, Glatz JF, et al. Long-chain fatty acid uptake and FAT/CD36 translocation in heart and skeletal muscle. Biochim Biophys Acta, 2005 Oct 1;1736(3):163-80.

6. Fielding BA, Frayn KN. Lipoprotein lipase and the disposition of dietary fatty acids. Br J Nutr, 1998 Dec;80(6):495-502.

7. McTernan PG, Harte AL, et al. Insulin and rosiglitazone regulation of lipolysis and lipogenesis in human adipose tissue in vitro. Diabetes, 2002 May;51(5):1493-8.

8. Kastin AJ, Redding TW, et al. Lipid mobilizing hormones of the hypothalamus and pituitary. Pharmacol Biochem Behav, 1975;3(1 Suppl):121-6.

9. Ahmadian M, Duncan RE, et al. The skinny on fat: lipolysis and fatty acid utilization in adipocytes. Trends Endocrinol Metab, 2009 Nov;20(9):424-8.

10. Miyoshi H, Souza SC, et al. Perilipin promotes hormone-sensitive lipase-mediated adipocyte lipolysis via phosphorylation-dependent and -independent mechanisms. J Biol Chem, 2006 Jun 9;281(23):15837-44.

11. Lafontan M, Langin D. Lipolysis and lipid mobilization in human adipose tissue. Prog Lipid Res, 2009 Sep;48(5):275-97.

12. Jaworski K, Ahmadian M, et al. AdPLA ablation increases lipolysis and prevents obesity induced by high-fat feeding or leptin deficiency. Nat Med, 2009 Feb;15(2):159-68.

13. Ahmadian M, Duncan RE, et al. Adipose overexpression of desnutrin promotes fatty acid use and attenuates diet-induced obesity. Diabetes, 2009 Apr;58(4):855-66.

14. Bays HE. "Sick fat," metabolic disease, and atherosclerosis. Am J Med, 2009 Jan;122(1 Suppl):S26-37.

15. Walewski JL, Ge F, et al. Adipocyte Accumulation of Long-Chain Fatty Acids in Obesity is Multifactorial, Resulting from Increased Fatty Acid Uptake and Decreased Activity of Genes Involved in Fat Utilization. Obes Surg, 2009 Oct 29. [Epub ahead of print]

16. Guilherme A, Virbasius JV, et al. Adipocyte dysfunctions linking obesity to insulin resistance and type 2 diabetes. Nat Rev Mol Cell Biol, 2008 May;9(5):367-77.

17. Schenk S, Saberi M, et al. Insulin sensitivity: modulation by nutrients and inflammation. J Clin Invest, 2008 Sep;118(9):2992-3002.

18. Jaworski K, Sarkadi-Nagy E, et al. Regulation of triglyceride metabolism. IV. Hormonal regulation of lipolysis in adipose tissue. Am J Physiol Gastrointest Liver Physiol, 2007 Jul;293(1):G1-4.
19. Villena JA, Roy S, et al. Desnutrin, an adipocyte gene encoding a novel patatin domain-containing protein, is induced by fasting and glucocorticoids: ectopic expression of desnutrin increases triglyceride hydrolysis. J Biol Chem, 2004 Nov 5;279(45



A.C.E. Certified Personal Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 28+ years and have studied kinesiology and nutrition

hope516

bump

lungry1980

Thanks!

Hearts_2015

bump

Pam3

wow!!!thanks for the info

MalDunc2012

bump

allybay

too wordy to read at the moment.. :-)

ninerbuff

How Fat Cells Work

by Craig Freudenrich, Ph.D.

Whether due to concern for related health risks (high blood pressure, heart disease, diabetes, sleep apnea, respiratory problems, etc.), or just for sheer aesthetics, many Americans worry about fat. In fact, at this very moment, thousands of Americans are exercising or dieting to reduce their amount of body fat. But have you ever wondered what fat is? When a person "gets fat" -- gains weight -- what is actually happening inside the person's body? What are "fat cells" and how do they work?

­Fat, or adipose tissue, is found in several places in your body. Generally, fat is found underneath your skin (subcutaneous fat). There's also some on top of each of your kidneys. In addition to fat tissue, some fat is stored in the liver, and an even smaller amount in muscle.

Where fat is concentrated in your body depends upon whet her you are a man or woman:

An adult man tends to carry body fat in his chest, abdomen and buttocks, producing an "apple" shape.
An adult woman tends to carry fat in her breasts, hips, waist and buttocks, creating a "pear" shape.

The difference in fat location comes from the sex hormones estrogen and testosterone. Fat cells are formed in the developing fetus during the third trimester of pregnancy, and later at the onset of puberty, when the sex hormones "kick in." It is during puberty that the differences in fat distribution between men and women begin to take form. One amazing fact is that fat cells generally do not generate after puberty -- as your body stores more fat, the number of fat cells remains the same. Each fat cell simply gets bigger! (There are two exceptions: the body might produce more fat cells if an adult gains a significant amount of weight or has liposuction performed.)

Body Fat Basics

The human body contains two types of fat tissue:

White fat is important in energy metabolism, heat insulation and mechanical cushioning.
Brown fat is found mostly in newborn babies, between the shoulders, and is important for thermogenesis (making heat). Since adult humans have little to no brown fat, we'll concentrate on white fat in this article. See the bottom of this page for more on brown fat.

Fat tissue is made up of fat cells, which are a unique type of cell. You can think of a fat cell as a tiny plastic bag that holds a drop of fat. White fat cells are large cells that have very little cytoplasm, only 15 percent cell volume, a small nucleus and one large fat droplet that makes up 85 percent of cell volume.
How Fat Enters Your Body

When you eat food that contains fat, mostly triglycerides, it goes through your stomach and intestines. In the intestines, the following happens:

Large fat droplets get mixed with bile salts from the gall bladder in a process called emulsification. The mixture breaks up the large droplets into several smaller droplets called micelles, increasing the fat's surface area.
The pancreas secretes enzymes called lipases that attack the surface of each micelle and break the fats down into their parts, glycerol and fatty acids.
These parts get absorbed into the cells lining the intestine.
In the intestinal cell, the parts are reassembled into packages of fat molecules (triglycerides) with a protein coating called chylomicrons. The protein coating makes the fat dissolve more easily in water.
The chylomicrons are released into the lymphatic system -- they do not go directly into the bloodstream because they are too big to pass through the wall of the capillary.
The lymphatic system eventually merges with the veins, at which point the chylomicrons pass into the bloodstream.

You might be wondering why fat molecules get broken down into glycerol and fatty acids if they're just going to be rebuilt. This is because fat molecules are too big to easily cross cell membranes. So when passing from the intestine through the intestinal cells into the lymph, or when crossing any cell barrier, the fats must be broken down. But, when fats are being transported in the lymph or blood, it is better to have a few, large fat molecules than many smaller fatty acids, because the larger fats do not "attract" as many excess water molecules by osmosis as many smaller molecules would.

Fat Storage

In the last section, we learned how fat in the body is broken down and rebuilt into chylomicrons, which enter the bloodstream by way of the lymphatic system.

Chylomicrons do not last long in the bloodstream -- only about eight minutes -- because enzymes called lipoprotein lipases break the fats into fatty acids. Lipoprotein lipases are found in the walls of blood vessels in fat tissue, muscle tissue and heart muscle.
Insulin

When you eat a candy bar or a meal, the presence of glucose, amino acids or fatty acids in the intestine stimulates the pancreas to secrete a hormone called insulin. Insulin acts on many cells in your body, especially those in the liver, muscle and fat tissue. Insulin tells the cells to do the following:

Absorb glucose, fatty acids and amino acids
Stop breaking down glucose, fatty acids and amino acids; glycogen into glucose; fats into fatty acids and glycerol; and proteins into amino acids
Start building glycogen from glucose; fats (triglycerides) from glycerol and fatty acids; and proteins from amino acids

The activity of lipoprotein lipases depends upon the levels of insulin in the body. If insulin is high, then the lipases are highly active; if insulin is low, the lipases are inactive.

The fatty acids are then absorbed from the blood into fat cells, muscle cells and liver cells. In these cells, under stimulation by insulin, fatty acids are made into fat molecules and stored as fat droplets.

It is also possible for fat cells to take up glucose and amino acids, which have been absorbed into the bloodstream after a meal, and convert those into fat molecules. The conversion of carbohydrates or protein into fat is 10 times less efficient than simply storing fat in a fat cell, but the body can do it. If you have 100 extra calories in fat (about 11 grams) floating in your bloodstream, fat cells can store it using only 2.5 calories of energy. On the other hand, if you have 100 extra calories in glucose (about 25 grams) floating in your bloodstream, it takes 23 calories of energy to convert the glucose into fat and then store it. Given a choice, a fat cell will grab the fat and store it rather than the carbohydrates because fat is so much easier to store.

Breaking Down Fat

When you are not eating, your body is not absorbing food. If your body is not absorbing food, there is little insulin in the blood. However, your body is always using energy; and if you're not absorbing food, this energy must come from internal stores of complex carbohydrates, fats and proteins. Under these conditions, various organs in your body secrete hormones:

pancreas - glucagon
pituitary gland - growth hormone
pituitary gland - ACTH (adrenocorticotropic hormone)
adrenal gland - epinephrine (adrenaline)
thyroid gland - thyroid hormone

These hormones act on cells of the liver, muscle and fat tissue, and have the opposite effects of insulin.

When you are not eating, or you are exercising, your body must draw on its internal energy stores. Your body's prime source of energy is glucose. In fact, some cells in your body, such as brain cells, can get energy only from glucose.

The first line of defense in maintaining energy is to break down carbohydrates, or glycogen, into simple glucose molecules -- this process is called glycogenolysis. Next, your body breaks down fats into glycerol and fatty acids in the process of lipolysis. The fatty acids can then be broken down directly to get energy, or can be used to make glucose through a multi-step process called gluconeogenesis. In gluconeogenesis, amino acids can also be used to make glucose.

In the fat cell, other types of lipases work to break down fats into fatty acids and glycerol. These lipases are activated by various hormones, such as glucagon, epinephrine and growth hormone. The resulting glycerol and fatty acids are released into the blood, and travel to the liver through the bloodstream. Once in the liver, the glycerol and fatty acids can be either further broken down or used to make glucose.

Losing Weight and Losing Fat

Your weight is determined by the rate at which you store energy from the food that you eat, and the rate at which you use that energy. Remember that as your body breaks down fat, the number of fat cells remains the same; each fat cell simply gets smaller.

Most experts agree that the way to maintain a healthy weight is:

Eat a balanced diet - appropriate amounts of carbohydrates, fat and protein
Do not eat excessively - for most people, a diet of 1,500 to 2,000 calories a day is sufficient to maintain a healthy weight
Exercise regularly



A.C.E. Certified Personal Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 28+ years and have studied kinesiology and nutrition

meeulk

I need someone to explain the whole "sleep in important" thing to my children.

yes! please! I have a 14 month old that's slept through the night maybe 7 nights his entire life.... *yawn*

hdlb123

I need someone to explain the whole "sleep in important" thing to my children.

Mine too please!

Sarauk2sf

Bump so I can read later

brandiuntz

Great thread! Lots of excellent information.

aquarianpixi

bump to read later

SandyMilton

bumping to get on my list for following

ninerbuff

Learning how fat accumulates and how you can use it will make it easier to understand why exercise makes the difference and that diet alone isn't the best approach.


A.C.E. Certified Personal Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 28+ years and have studied kinesiology and nutrition

blackrock2012

--

ninerbuff

Many people don't know that you can't get rid of fat cells. You can only shrink their size.


A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 28+ years and have studied kinesiology and nutrition