Visceral fat and your heart

Scientists have discovered the origin of the “bad” kind of fat found in the body which is linked with heart disease, cancer and other serious obesity-related illnesses, even though people carrying it can look slim.

The fat that builds up around abdominal organs such as the heart, kidney and intestine – known as visceral fat – is considered a silent killer because it’s possible for people to have a lot of it without looking particularly overweight.

It is more dangerous than the subcutaneous fat layers stored beneath the skin, and now researchers have found that it stems from a different source because it derives from a specific type of cell found in the developing embryo when it is still in the womb.

The discovery could eventually lead to new ways of controlling how this kind of cell contributes to the bad fat surrounding the vital organs so that it becomes possible to lower the chances of developing the kind of obesity that raises the risk of serious disease, they said.

A study on genetically modified mice found that 80 per cent of the visceral fat of the abdomen comes from embryonic cells known from a gene that they express called Wt1, which is linked with kidney tumours. Subcutaneous fat has a different origin and does not express the Wt1 gene, the researchers found.

The heart
The heart

“Determining the origins of good and bad fat has been one of the big unanswered questions in obesity research. We’ve now shown that most bad fat comes from cells expressing the Wt1 gene in the later stages of pregnancy,” said You-Ying Chau of Edinburgh University.

“We also found that cells expressing Wt1 continue to act as a source of visceral fat into adulthood where they may be influenced by external factors such as diet. If we would find a way to control the regulation of these cells, we might be able to stop the body laying down any more bad fat around the organ,” said Dr Chau, the lead author of the study in Nature Cell Biology.

Professor Nick Hastie of the Medical Research Council’s Human Genetics Unit in Edinburgh said although the visceral fat of the abdomen is formed after birth, it originates from embryonic cells in the womb which are also involved with forming the protective mesothelium membrane around the six visceral fat depots of the abdomen.

“We found strong evidence for the existence of a mesothelium, which was a big surprise because nobody thought this membrane existed in fat. It seems that not only does the mesothelium help to produce the cells that make the fat, it also surrounds the fat, making it into a neat little organ,” Professor Hastie said.

Want to lose some belly fat ? – 2

Can monounsaturated fats banish belly fat?

A diet book called ‘The Flat Belly Diet’ posits the idea that you can lose belly fat by eating a 1,600-calorie diet rich in monounsaturated fats.

Most people will lose weight on a 1,600-calorie diet. There is little question that when it comes to choosing fats, the monounsaturated fatty acids (MUFAS) found in UK vegetable oil, rapeseed oil, olive oil, olives, avocados, nuts and seeds are among the best choices, with proven health benefits such as reducing the risk of heart disease.

However, these are not magic foods capable of targeting belly fat, experts note. While the MUFAS are healthy fats, they are still fats, with nine calories per gram – more than twice that of carbohydrates and proteins, which have four calories per gram, and alcohol at 7kcal per gram.

“I wouldn’t advise a certain number of calories in a diet because people have different calorie needs,” says Priya Tew. “Men need more calories than women, for example. But cutting down on saturated fats and swapping to monounsaturated fats is healthy for your heart.”

Can exercise flatten your abs?

Hundreds of crunches each day won’t flatten your belly if you need to lose weight. If your abdominal muscles aren’t covered with excess fat, strengthening them can help you look tighter and thinner. However, spot exercises won’t banish belly fat.

“It’s much easier to lose weight if you do a combination of diet and exercise together,” says Priya Tew. “By becoming more active, you’re definitely going to improve your chances of losing weight and keeping weight off.”

Doing physical activity is important, says Professor Bell, because you not only get the benefit of burning fat at the moment of exercising, but you also get a long term benefit of changing your white fat (slow burning subcutaneous fat) into beige fat, which is much more metabolically active. In other words, the more you exercise, the easier it becomes to burn fat.

Professor Bell says that people who control their weight through dieting alone tend to accumulate lots of visceral fat.

The risks of excess belly fat

Why is it important to lose belly fat? Carrying around extra pounds in your midsection is serious business. Extra weight as body fat wrapped around your internal is more dangerous than fat around your hips and thighs or subcutaneous fat that sits under the skin.


“There is a strong link between excess belly fat and cardiovascular disease, high blood pressure, type 2 diabetes and high cholesterol, all of which can have significant effects on quality of life and life expectancy,” says Dr Clarke.

We tend to think of body fat as relatively inert, just sitting there until we use it. Medical research over the last decade has shown increasingly that body fat is ‘metabolically active’, and can generate lipokines, inflammatory chemicals that up-regulates body inflammation. Not only is this undesirable for those with the pain of chronic conditions like arthritis, but higher levels of inflammation sensitize artery walls, accelerating damage that causes atherosclerosis. That’s why losing weight benefits both heart health and people with painful conditions alike.

Is your middle too big?

A simple way to determine if you are carrying too much weight around your middle is by measuring your waist, says Dr Clarke.

To assess your risk use a soft tape measure. First, make sure to measure your ‘real’ waist size – which isn’t the thinnest part of your abdomen. Your ‘true’ waist is found mid-way between your hip bone and your lowest rib. Take the measurement around this part of your bare abdomen without holding your breath, or holding your stomach in.

If your waist is larger than 102 cm (40 in) for men or 88 cm (35 in) for women, you have too much belly fat and are at risk of heart disease and other conditions. One of the best things you can do for your health is to lose weight.

The bottom line about belly fat

So what’s the bottom line about belly fat?

Most scientific evidence suggests that a calorie-controlled diet rich in fruits, vegetables, whole grains, low-fat dairy, beans, nuts, seeds, lean meat, fish, eggs and poultry is the foundation of a diet that provides all the nutrients you need while helping to whittle your waistline.

The real secret to losing belly fat is to lose weight on a balanced, calorie-controlled diet and exercise at least an hour a day.