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The Omentum and Abdominal Fat: Health Benefits and Problems

Updated on April 7, 2017
AliciaC profile image

Linda Crampton is a teacher with a first class honors degree in biology. She writes about human biology and the scientific basis of disease.

Having an apple-shaped body is more dangerous than having a pear-shaped one. The omentum contributes to the apple shape.
Having an apple-shaped body is more dangerous than having a pear-shaped one. The omentum contributes to the apple shape. | Source

Subcutaneous and Visceral Fat

The greater omentum is a fatty membrane that covers the small and large intestine. Until recently its only function was thought to be the storage of fat. Now researchers have discovered that it not only has other functions but also has some important health benefits. However, it seems to be a "Jekyll and Hyde" structure. If it contains too much fat it has the potential to cause serious health problems.

There are two types of fat in the abdominal area—subcutaneous and visceral. Subcutaneous fat is located under the skin and above the muscles. It's the soft fat that we can feel when we grab hold of our skin. Visceral fat lies below the muscles in the omentum and around the organs.

Excess visceral fat can have a more serious effect on our health than excess subcutaneous fat. Health experts say that those of us who have an apple-shaped body (one with excess fat in the abdomen) have a higher risk for certain health problems than those of us with a pear-shaped body (one which collects fat in the hips and thighs). An omentum containing a lot of fat contributes to the apple shape.

The stomach, small intestine, and large intestine; the longest part of the large intestine is the colon
The stomach, small intestine, and large intestine; the longest part of the large intestine is the colon | Source

The Peritoneum

The peritoneum and the greater omentum are membranous structures in the abdomen. The peritoneum is a smooth, glistening membrane on top of connective tissue. It lines the abdominal cavity and covers the organs in the abdomen. It's a continuous sheet but is given different names according to its location. The parietal peritoneum lines the inside of the abdomen and the visceral peritoneum covers the organs. The omentum is made of peritoneum.

The greater omentum hangs from the stomach like an apron. The liver has been lifted out of the way in this illustration.
The greater omentum hangs from the stomach like an apron. The liver has been lifted out of the way in this illustration. | Source

The Greater and Lesser Omentum

An omentum is a sheet-like structure made of a double layer of peritoneum. It contains a variable amount of fat. There are actually two omenta—the greater omentum and the lesser omentum.

The greater omentum is attached to the greater curvature of the stomach, which is the outer curve furthest away from the midline of the body. The omentum hangs over the small and large intestine, resembling an apron, and then folds back on itself to attach to the transverse colon. This is a horizontal section of the colon below the stomach. The greater omentum is often referred to as simply "the omentum".

The lesser omentum is much smaller than the greater one. It's attached to the lesser curvature of the stomach, which is the inner curve nearest to the midline of the body, and extends over the first part of the small intestine and the edge of the liver.

Parts of the Stomach

The lesser omentum is attached to the lesser curvature of the stomach while the greater omentum is attached to the greater curvature.
The lesser omentum is attached to the lesser curvature of the stomach while the greater omentum is attached to the greater curvature. | Source

In most illustrations of the abdominal cavity, the omenta and peritoneum are removed in order to show the organs clearly. Some people may be surprised to learn that the membranes exist.

Fat Storage

A healthy omentum is a thin, pale yellow sheet that contains fat and often has a lacy appearance. Fat is an essential substance in our body. It only becomes dangerous when it's present in an excessive amount or in the wrong place.

If the omentum absorbs extra fat it becomes thicker and harder. An enlarged omentum may push the front of the abdomen outwards, producing a beer belly or potbelly.

For a long time it was thought that the omentum wasn't important, except as a minor fat storage depot. Now there is evidence that it does more than just store fat and actually has some important functions.

Dr. Oz Describes and Shows the Omentum

The Immune System

The omentum contains "milky spots", which are collections of macrophages. Macrophages are a type of white blood cell and fight bacteria and viruses. The action of the macrophages in the omentum may help the immune system. This system protects us from disease.

Research suggests that the omentum may also suppress certain aspects of the immune system, at least in mouse cells studied in lab equipment. The discovery may or may not apply to the omentum inside our body. The researchers examined the effect of mouse omentum cells on T cells (or T lymphocytes) from mice. T cells are a very important part of the immune system. They attack and destroy invaders such as bacteria, viruses, and cells from other people.

T cells become activated in order to do their job. The researchers mixed omentum cells with activated T cells in laboratory equipment and found that the T cells died. T cells that hadn't been activated were unaffected by the omentum cells. The omentum cells apparently produced a substance that killed the activated T cells.

If this reaction occurs in humans it could be very significant. It may sound bad that T cells are killed by omentum cells, but in some conditions—such as organ transplants and autoimmune diseases—the immune system needs to be suppressed. An autoimmune disease is one in which a person's immune system attacks their own body. The discovery that the omentum may have the ability to dampen immune system activity could lead to improved methods for treating autoimmune diseases.

A red blood cell (on the left), a platelet, and a T lymphocyte; the omentum may affect the activity of activated T lymphocytes
A red blood cell (on the left), a platelet, and a T lymphocyte; the omentum may affect the activity of activated T lymphocytes | Source

Stem Cells

More and more researchers are finding evidence that the omentum functions in tissue repair and regeneration. In fact, some believe that this is the omentum's primary job. Surgeons sometimes attach bits of omentum to damaged tissues in the body. They know from experience that this process stimulates tissue repair, but how it does this is uncertain.

The omentum may stimulate tissue regeneration because it contains mesenchymal stem cells, or MSCs. Stem cells are very important because they are capable of forming other cell types. This isn't true for the other cells in our body. In lab flasks, MSCs from the omentum have produced bone cells and cells that resemble lung cells.

Finding good sources of stem cells is important because they have the ability to repair damage. Human embryos are a good source of the cells, but the use of embryos is controversial. Obtaining the stem cells kills the embryos. Obtaining stem cells from adults (harmlessly) avoids this problem.

The Benefits of Losing Visceral Fat

Visceral fat is stored around our organs and in our omentum. Although all excess fat can be dangerous, visceral fat may be especially so.

Dangers of Excess Visceral Fat

While the omentum seems to have some impressive and helpful functions, there's no doubt that excess visceral fat in the omentum is dangerous. The fat cells are metabolically active and release a variety of chemicals. Some serve as messengers in the body and others trigger harmful inflammation. Fatty acids are also released from omental fat. These reach the hepatic portal vein, which transports them to the liver.

An excessive amount of visceral fat increases the risk of cardiovascular disease, hypertension (high blood pressure), high fasting blood sugar, insulin resistance, and type 2 diabetes. It also raises the blood level of LDL cholesterol (the bad cholesterol) and increases the risk of certain types of cancer. In addition, it seems to increase the chance of developing non-alcoholic liver disease.

Men generally have a larger tendency to develop visceral fat in the abdomen than women. After menopause a woman's tendency to store visceral fat increases, however. The tendency is also influenced by genetic factors.

Fat in the diet should be a healthy type, such as the omega-3 fat in wild salmon.
Fat in the diet should be a healthy type, such as the omega-3 fat in wild salmon. | Source

Detecting the Presence of Hidden Fat

If we don't have a beer belly, how do we know that we have too much visceral fat? Health professionals say that our waist size is an indication that we're likely to have excess visceral fat and may be a more accurate indicator of potential health problems than the Body Mass Index, or BMI.

For a person of average height, a waist size over thirty-five inches in females and over forty inches in males may be a danger sign. Another guideline states that a person's waist size should be no more than half their height.

Yogurt can be a healthy food.
Yogurt can be a healthy food. | Source

People who have serious health, weight, or nutritional issues should visit their doctor to get lifestyle advice appropriate for their situation.

Losing Abdominal Fat

Reducing calorie intake and getting regular, moderately intense exercise is the best way to lose abdominal fat, according to many health experts. Severely restricting calories will probably make a diet very hard to maintain, however. The best plan is to make permanent and healthy lifestyle changes instead of "going on a diet".

Improve the Diet

Nutritionists generally recommend a diet that emphasizes unprocessed or minimally processed foods from plants and consists of vegetables, fruits, whole grains, legumes or pulses, lean protein, low-fat dairy, and moderate amounts of monounsaturated and polyunsaturated fats. Foods that contain healthy fats include nuts and seeds, some fish and certain vegetable oils. Even "healthy" foods may be high in calories, however, so it's important to be aware of the calorie content of foods. For example, fruit smoothies may be loaded with calories as well as nutrients.

Scientists have found that even a small amount of weight loss— five to ten percent of a person's weight—is likely to have substantial health benefits. It's a great goal to aim for even if it doesn't have a huge effect on a person's appearance. Some research indicates that visceral fat is lost before subcutaneous fat when we reduce our calorie intake.

Start an Exercise Program

Anyone starting a new exercise program should begin with relatively easy exercise sessions that last for a short period. This will reduce the chance of injury. The intensity and duration of the sessions should increase slowly over time. If someone is very overweight they should see a doctor before they start exercising.

Get Enough Sleep

Getting an adequate amount of sleep is also important in a healthy lifestyle. Interestingly, scientists have discovered that lack of sleep is linked to an increased amount of visceral and subcutaneous fat.

Whole grain bread is a good food for a healthy diet.
Whole grain bread is a good food for a healthy diet. | Source

The Definition of Obesity

Some scientists have suggested that we need a new definition of obesity that is based on the location of body fat. A person who looks overweight may have a lot of subcutaneous fat but not much visceral fat. This person may be healthy and have a low risk of many serious health problems. On the other hand, someone who looks thin may actually be unhealthy because they have a lot of visceral fat around their organs.

Sumo wrestlers are an example of people who look obese but are relatively healthy. Most of their fat is subcutaneous, not visceral. However, when they retire from wrestling and regular exercise, the amount of visceral fat in their body increases.

There are medical scans that can detect visceral fat, but most of us don't have access to these scans. The best that we can do is to follow a healthy lifestyle and monitor our waist size in relation to our height. Even if our waist size is appropriate, we don't know how much fat is hiding deep inside our abdomen below the omentum. A healthy lifestyle is therefore important for everyone.

References

© 2013 Linda Crampton

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    • drbj profile image

      drbj and sherry 4 years ago from south Florida

      Fascinating facts about the omentum, Alicia. It's particularly interesting to me that scientists may be finding evidence that the omentum does more than simply store fat, and may function in both tissue repair and regeneration. Thanks for the newsflash. Voted up, y'know.

    • AliciaC profile image
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      Linda Crampton 4 years ago from British Columbia, Canada

      Thank you for the comment and the vote, drbj, especially so soon after I published the hub!

    • billybuc profile image

      Bill Holland 4 years ago from Olympia, WA

      Thank you for the facts and suggestions. Whatever it is called I have about ten pounds of it that I need to lose. :)

    • AliciaC profile image
      Author

      Linda Crampton 4 years ago from British Columbia, Canada

      Thanks for the visit and the comment, Bill. Good luck with the weight loss!

    • shiningirisheyes profile image

      Shining Irish Eyes 4 years ago from Upstate, New York

      Great article and very informative. The omentum performs quite of processes...immune system function, T-cell regulator, aiding in tissue repair. The need for optimal omentum and abdominal fat level balance seems quite evident after reading this article. Concise tips and suggestions are appreciated as well.

      Voting up and sharing

    • vocalcoach profile image

      Audrey Hunt 4 years ago from Nashville Tn.

      I've been recently diagnosed with type 11 diabetes so along with a healthy diet started a walking program. Hope I lose some of my visceral fat :)

      Learned some awesome facts here which is why I voted up, useful, awesome, interesting and sharing.

    • AliciaC profile image
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      Linda Crampton 4 years ago from British Columbia, Canada

      Thank you very much for the comment, the vote and the share, shiningirisheyes!

    • AliciaC profile image
      Author

      Linda Crampton 4 years ago from British Columbia, Canada

      Thank you so much for all the votes and the share, vocalcoach. I'm sorry that you have diabetes. I hope the treatment goes well!

    • ytsenoh profile image

      Cathy 4 years ago from Louisiana, Idaho, Kauai, Nebraska, South Dakota, Missouri

      Alicia, thanks much for your hub. I have never heard of an "omentum" before, so I learned something new again in the hubs. I agree that we need to develop a healthy eating lifestyle, getting appropriate sleep and incorporating exercise into our daily routine. It's interesting to me that at least for myself, I usually only think about the bigger organs more since I'm not aware of all the medical terms surrounding those organs. Sure don't like the visceral fat part. Thumbs up on your presentation of advice!

    • AliciaC profile image
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      Linda Crampton 4 years ago from British Columbia, Canada

      Thank you very much for the comment, ytsenoh! I appreciate it. (I don't like the idea of visceral fat building up, either!)

    • MJennifer profile image

      Marcy J. Miller 4 years ago from Arizona

      This was quite interesting, Alicia. I'm paying a lot more attention to my midsection as I rapidly close in on 50 and have noticed that my perpetually-skinny body from the past is now, sadly, in the past. Everything now seems to go straight to my waistline as it never had before. I need to develop some momentum to reduce my omentum!

    • AliciaC profile image
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      Linda Crampton 4 years ago from British Columbia, Canada

      Hi, MJennifer. Thanks for the visit. I'm experiencing the difficulty in staying slim as the years pass, too! The battle certainly becomes harder as we get older.

    • AliciaC profile image
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      Linda Crampton 4 years ago from British Columbia, Canada

      Thanks for the comment and the votes, sarifearnbd!

    • aviannovice profile image

      Deb Hirt 4 years ago from Stillwater, OK

      I like my sweets, I will grant you that, but since I pretty much became a vegetarian, I have become very lean over the past couple ofm years. That, with walking around Boomer Lake, has sure done me a world of good. I have a higher energy level at work better than most of the youngsters there. Great article! I had heard about the omentum, but this piece went into so much more depth.

    • AliciaC profile image
      Author

      Linda Crampton 4 years ago from British Columbia, Canada

      Hi, Deb. It's very interesting to hear that that being a vegetarian has kept you lean. (I like my sweets, too!) Thanks for the comment.

    • Nell Rose profile image

      Nell Rose 4 years ago from England

      Hi Alicia, I always learn something new when I read your health hubs, I totally agree about not dieting but keeping to a proper food regime, I have tried diets and they just do not work. I never knew about this fat before, fascinating hub, and so useful, nell

    • AliciaC profile image
      Author

      Linda Crampton 4 years ago from British Columbia, Canada

      Thanks, Nell. I agree - diets don't work for most of us! Even though they may cause weight loss, people often put the weight back on because they can't stick to the diet.

    • Relationshipc profile image

      Kari 4 years ago from Alberta, Canada

      Excellent hub. I would love to see what my omentum looks like right now...by the look of my stomach, I would have to say not very good - probably a lot like that second omentum in the video.

      I know that Avian said she was a vegetarian and became lean, but I don't want anyone to think it is that easy. I've been a vegetarian since I was 15 (I'm 35) and my weight has fluctuated between 140 to 190.

      There are plenty of unhealthy vegetarian foods - chips, sugar filled foods, fried foods, etc...It's the choices you make about what you eat and how much you eat that helps you keep trim, not the diet itself. Sounds like Avian is making the right choices! :)

    • AliciaC profile image
      Author

      Linda Crampton 4 years ago from British Columbia, Canada

      Thank you very much for the informative comment, Relationshipc. I think that many of us would be shocked if we could see our omentum! A technique that easily and harmlessly allows us to do this would be a great way to encourage weight loss.

    • DDE profile image

      Devika Primić 3 years ago from Dubrovnik, Croatia

      The Omentum and Abdominal Fat interesting and useful hub about such fat, informative and well pointed out

    • AliciaC profile image
      Author

      Linda Crampton 3 years ago from British Columbia, Canada

      Hi, DDE. Thanks for the visit and the comment. The omentum is an interesting part of our body!

    • profile image

      terri 8 months ago

      how does a person get dead areas as a result of no blood flow to that area in the omentum

    • AliciaC profile image
      Author

      Linda Crampton 8 months ago from British Columbia, Canada

      Hi, terri. The omentum contains living cells that obtain oxygen and nutrients from the bloodstream and send waste substances into the blood. If the blood supply to a section of the omentum is blocked, the cells in the area may die because they can no longer obtain what they need.

    • profile image

      Thomas Sherwin 6 weeks ago

      Good info. I can now see why beta cell transplant into viseral fat is showing great results.......

    • AliciaC profile image
      Author

      Linda Crampton 5 weeks ago from British Columbia, Canada

      Hi, Thomas. I've never heard about what you've mentioned. I have read about fat cells being transformed into beta cells, but that's still an experimental procedure according to what I've read.

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