You indulge in dessert at every meal and yet, you still maintain a slim figure. Don’t be too happy. You could be TOFI – or thin on the outside, fat on the inside. Yes, people who don’t look overweight can have “internal fat”, or visceral fat, which is more of a threat to health than the fat that lies just under the skin – the fat you can pinch. While the TOFI phenomenon surfaced in the West about seven years ago, what’s getting doctors here concerned is that younger women in Singapore are having the condition, which normally shows up in women above 35 or who have been through menopause.

Dr Wong Choo Wai, senior family physician at Bedok and Jurong Day and Night Clinic, says he used to see one case every few months two years ago. Now, he sees at least one or two a month. This year, he saw five teenagers with slim figures who had high cholesterol counts – a sure indicator of visceral fat. Dr Alvin Wong, medical director of Well Family Clinic & Surgery, agrees. He says that one in 20 of his apparently slim women patients, aged 25 to 30, turn out to have a fatty liver – a confirmation of high visceral fat. Ten years ago, the number was far fewer. “And they were usually older women,” he adds.

What it is

Visceral fat collects around the internal organs, like the liver, heart and pancreas, and in the abdomen – particularly dangerous because it is thought to play havoc with normal hormone and chemical functions, thus increasing the risk of illnesses like diabetes and heart disease.

Internal fat is also metabolised by the liver, turning it into cholesterol that circulates in the blood. “Bad” cholesterol or LDL, short for low density lipoproteins, collects in the arteries and forms plaque, which leads to narrowing of the arteries and ailments like high blood pressure.

Fat cells are akin to chemical factories. They produce substances that contribute to diabetes, heart disease, strokes and even some cancers. When you put on weight, the cells grow larger and start to divide to produce more fat cells. An average-sized adult has 40 billion; an obese one two or three times the number.

Diets won’t help

TOFI is caused by a sedentary lifestyle coupled with a high sugar and high fat diet. High alcohol consumption is also a factor. Today’s young women are time-strapped, leading to healthier choices in food and less exercise. People with apple-shaped bodies, where excess calories are deposited in the abdomen area, are more at risk than the pear-shaped – the usual shape for women – who have fat in the hips, thighs and derrieres. Fortunately, visceral fat is easier to lose than the fat you can pinch, according to Dr Howard E. LeWine of Harvard Medical School in the US. Researchers in the US found that 30 minutes of brisk walking every day can prevent the growth of visceral fat – double the time you exercise, and you’ll start burning the fat. What also zaps internal fat is high-intensity interval training (short, sharp bursts of activity).

Don’t be TOFI (in 5 easy steps)

1. Cut out fat and sugar

Substitute coconut water or plain water for fizzy drinks. Steer clear of fruit juices that are 

2. Eat more polyunsaturated fat

More of this good fat (from fish, vegetable oils and nuts) prevents accumulation of excess fat around the torso.

3. Drink in moderation

When the liver is overloaded with alcohol, it can’t digest fat properly and is the first place where visceral fat forms.

4. Don’t go on crash diets

When you drastically cut calories, you lose muscle bulk, so the body can’t burn visceral fat well.

5. Exercise

Just 30 minutes of brisk walking every day can prevent the growth of visceral fat.

This story was originally published in Her World magazine October 2012.