It’s a well-known fact: obesity increases your risk of chronic diseases such as type 2 diabetes. However, this doesn’t mean that thinner people are unlikely to develop such conditions. In fact, even if you’re generally trim, you still need to watch out for an excess of visceral fat, or fat around the internal organs.

Dr Ian Phoon, Associate Consultant from SingHealth Polyclinics - Pasir Ris, a member of the SingHealth group, explains more about this “thin outside, fat inside” phenomenon.

Why is visceral fat (belly fat) dangerous?

“Visceral fat is fat that you may not see, but accumulates around your organs. Visceral fat is more dangerous since it results in greater insulin resistance compared to sub-cutaneous fat, or fat under the skin,” says Dr Phoon.

Insulin resistance is when the body produces insulin, but is unable to properly use it to control blood sugar. Glucose (sugar) builds up in the blood, leading to diabetes.

Asians, especially South Asians, are genetically more prone to accumulating visceral fat, compared to Caucasians. Unhealthy lifestyles, such as a lack of exercise and eating foods high in calories (including soft drinks) and saturated fats (fried foods, fatty meats, lard, ghee, “junk” foods, etc.), also promote excess visceral fat.

Drinking excess alcohol can also increase visceral fat, and it may manifest as a “beer belly”. The Health Promotion Board recommends that men don’t drink more than 30g of alcohol a day, and women not more than 20g. One can of beer (330 ml) contains about 15g of alcohol and one glass of wine (100 ml), about 10g.

“Although men have lesser overall percentage body fat than women, they tend to accumulate their fat in the abdominal area, while women generally have more fat in their hips and thighs. However, women who have given birth or who have menopaused are more prone to fat in the abdomen than other women,” adds Dr Phoon.

Diabetes in Singapore

According to the MOH (Ministry of Health) National Health Survey of 2010, type 2 diabetes is most prevalent among Indians/South Asian (17.2 per cent), followed by Malays (16.6 per cent) and Chinese (9.7 per cent).

Regardless of race, your risk of type 2 diabetes tends to increase if you:

  • Have a history of gestational diabetes (diabetes while you were pregnant)
  • Have parents who are diabetic
  • Take long-term oral steroids
  • Are above 40 years of age
  • Have pre-diabetes (your body has already started to become insulin-resistant but to a lesser extent than full-blown diabetes. This can be seen in your blood sugar test, which is higher than normal, but not as high as a diabetic.)

Can BMI measure visceral fat and diabetes risk?

Your BMI (body mass index) is a way to gauge your risk of type 2 diabetes. Generally speaking, the higher your BMI, the higher your risk of diabetes. The risk starts to increase from a BMI of 23 in Asians (25 for Caucasians).

However, the pitfall of using the BMI, says Dr Phoon, is that it does not distinguish between lean and fat mass. Thus if you do a lot of body-building, your BMI may be high without increasing your risk of type 2 diabetes.

There are two better ways to identify those with excess visceral fat:

  1. The waist circumference (WC) or
  2. The waist-hip ratio (WHR).

The following waist circumference (WC) measurements indicate an increased risk of diabetes and cardiovascular disease:

 AsianCaucasian
Men> 90 cm> 94 cm
Women> 80 cm> 80 cm

Source: International Diabetic Federation (IDF) 2006.

The formula for the waist-hip ratio (WHR) is as follows:

Waist-hip ratio (WHR) = Waist circumference ÷ Hip circumference

Regardless of race, a WHR > 0.9 in men and a WHR > 0.85 in women indicate an increased risk for diabetes, according to the World Health Organisation (WHO).

“A simpler way would be to take note if you can no longer fit into your pants! It may be a warning sign that your visceral fat is increasing,” says Dr Phoon.

How can I reduce the visceral fat deposits in my body?

The most effective way to reduce visceral fat is to eat healthy and exercise regularly. A healthy diet is one low in salt, saturated fats and oils, and high in fibre such as those in brown rice, wholemeal bread, fruits and leafy vegetables. Avoid eating for the sake of it. Stop eating if you don’t feel hungry. Aerobics-type exercises (the kind that raises your heart rate and breathing rate) are especially helpful, and should be done at least 3-5 times a week.

Unfortunately, despite the marketing claims of certain “health product” companies, there is no way to strictly target belly fat. Any slimming program that does not include a healthy diet and exercise is unlikely to have health benefits. In addition, it should be noted that liposuction only reduces subcutaneous fat, and not visceral fat. Thus it does not reduce your overall health risk.

Ref: R14