By Geraldine Ling
Why an expanding waistline puts a person at risk of heart disease and diabetes.
There is fat and there is fat and what lurks beneath - fat that cannot be felt just by pinching your belly - can be bad for your health if there is too much of it.
This visceral fat builds up and wraps itself protectively around vital organs, including those in the abdomen.
It is well known that excess visceral fat increases the risk of health issues such as heart disease and diabetes.
When it is visceral fat that is causing a person's girth to get wider, the person may even face an earlier death, a new study published in the journal Archives Of Internal Medicine reported last month.
The research, done over nine years, tracked more than 100,000 people aged 50 and above. Those with bigger waists were more likely to die of respiratory disease, followed by heart disease, then cancer.
While visceral fat protects abdominal organs, too much of it is hazardous to health.
Visceral fat breaks up more easily than subcutaneous fat which is found just below the skin, said Dr Asim Shabbir, a consultant at the Centre for Obesity Management and Surgery at the National University Hospital.
When visceral fat breaks up, it releases free fatty acids into the bloodstream.
These fatty acids then travel to the liver where they block certain pathways. Problems like insulin resistance and diabetes may arise.
One's waistline is a good gauge of the amount of visceral fat in the body, said Dr Asim.
Anything more than 102cm for men and 88cm for women will increase one's risk of problems related to excess visceral fat, he said.
Many Singaporeans may not be aware of the dangers of visceral fat. 'About half my patients do not know that obesity is linked to problems like diabetes and hypertension, much less the dangers of visceral obesity,' Dr Asim said.
Dr Roger Tian, a sports physician and associate consultant at the Singapore Sports Medicine Centre and Changi Sports Medicine Centre, agreed.
He said: 'Many people may not realise the dangers of visceral fat as it is hidden underneath the muscles and not as visible or cosmetically disturbing as subcutaneous fat, which can show up as flabby thighs.'
More men than women tend to accumulate visceral fat because of factors like genes and hormones. However, post-menopausal women also face an increased risk of developing excess visceral fat as a result of their losing oestrogen and its accompanying protective effects, said Dr Asim.
Also, as one ages regardless of gender, the battle of the bulge gets fiercer as one's basal metabolic rate (the rate at which a person's body burns energy at rest) decreases, said Dr Asim. This makes it easier to gain weight if one overeats or leads a sedentary lifestyle.
Still, there is some good news. Visceral fat is easier to lose than subcutaneous fat because it breaks down faster.
Low to moderate intensity aerobic exercises, say brisk walking, swimming or cycling, for at least 30 minutes a day, five times a week, are recommended, said Dr Tian.
He explained that a person exercising for just 10 to 20 minutes would be burning only carbohydrates. Fat is one of the metabolic fuels burnt only when a person engages in prolonged exercise, he added.
Results can be relatively quick if a sound diet is tagged onto a more active lifestyle.
What is visceral fat?
- It lies deep within the body and cannot be felt by pinching your belly. Subcutaneous fat lies under the skin and shows up as flabby body parts.
- When it breaks up, it releases free fatty acids into the bloodstream. These fatty acids then travel to the liver where they block certain pathways. Problems like insulin resistance and diabetes may arise.
- One's waistline is a good gauge of the amount of visceral fat in the body. Anything more than 102cm for men and 88cm for women will increase one's risk of health problems.