You might be skinny but are you fat?
You‘re in the ‘healthy’ weight range and you’re not pregnant but your waistline seems to be expanding. How is that possible? Nutritionist Cindy Williams explains.
What is visceral fat?
Visceral fat is an internal fat and quite different to subcutaneous fat. We can pinch subcutaneous fat as it sits just under the skin, but we can’t pinch visceral fat as it gathers around the abdominal organs – the heart, kidneys, pancreas and liver. So even if you’re thin on the outside, visceral fat could be lurking in your body – and it’s much more dangerous than the fat on hips and thighs.
What’s so bad about it?
We often think of fat as inert blobs of lard. But visceral fat is not inert. It’s very active – and it’s dangerous for our health.
Visceral fat is linked to high blood pressure, a greater risk of breast cancer in pre-menopausal women, and possibly early stage colorectal cancer.
Too much internal stomach fat increases your risk of heart disease, diabetes, metabolic syndrome, high blood pressure, colorectal cancer and breast cancer. And it doesn’t look good, either!
Visceral fat secretes hormones and immune system chemicals. These make cells more resistant to insulin and cause low-grade chronic inflammation – insulin resistance and inflammation both increase the risk of cardiovascular disease.
How do I know if I have it?
Researchers measure visceral fat using advance medical imaging techniques such as CT and MRI scans, but an easy, accurate and cheaper way is simply to measure the waist.
Without squeezing the skin, wrap the tape measure around your waist at the navel, or to be exact, at the top of your hipbone where it intersects with a line dropped vertically from the middle of the armpit. Breathe out normally.
The national guidelines for a healthy waist measurement in Europeans, Maori and Pacific Islanders is less than 100cm for men and less than 90cm for women. For Asian men and women, it’s less than 90cm and less than 80cm respectively. The lower figures are because Asian people generally have a slighter body frame. These numbers are a general guide to help people assess their health risk. It doesn’t account for individual variation.
I look normal and I’m a normal weight. Could I still have unhealthy visceral fat?
Measuring just your weight or body mass index (BMI) does not tell you what proportion is muscle or fat. It’s possible to be in the ‘normal’ weight or BMI range yet have too much fat around your tummy. This is when you can use the rather unscientific but logical ‘mirror test’! If you have a pot belly or if your tummy seems out of proportion to the rest of your body – and you can’t pinch it – you may have some visceral fat lurking inside.
Some people may be more genetically prone to gaining visceral fat than others. Scientists have found a number of genes which help determine how many fat cells we develop and where they are stored. So if your mother is an ‘apple’ shape, you may be prone, too.
Hormones also influence where fat is stored. Men and post-menopausal women have lower oestrogen levels which promote fat to settle more around the tummy. It’s common for women to gain visceral fat after menopause.
What can I do about it?
The good news is that visceral fat is easier to get rid of than subcutaneous fat. Healthy eating and exercise are both important, but exercise seems to be the key to moving visceral fat and keeping it off. Both aerobic and resistance training prevents regain of visceral fat after weight-loss. In one study, participants went on a weight-loss diet and were then followed up a year after finishing the diet. Those who kept exercising 40 minutes twice a week had regained no visceral fat a year later, even though they had regained some weight.
I have read there is a stress link with visceral fat – stress hormones make you gain abdominal fat. Is this true?
Probably – but more studies are needed. At the moment it’s an association, so we can say chronic stress may also contribute to visceral fat. Stress makes our bodies secrete cortisol – often called the ‘stress hormone’. Cortisol increases blood sugar levels and suppresses the digestive system preparing the body for ‘fight or flight’. If we are chronically stressed, our cortisol levels remain abnormally high. This appears to promote the accumulation of abdominal fat.
Tips to reduce visceral fat – and keep it off
- Be active every day. Walk, cycle, swim, garden, dance – at a moderate intensity. Add in some strength training with weights a few times a week.
- We can’t spot reduce fat but having strong abdominal muscles helps flatten our tummy. Do specific exercises to strengthen the deep abdominal muscles such as Pilates-style pelvic tilts, pelvic lifts and drawing in the bellybutton. Sit-ups don’t really work these muscles.
- De-stress. Do regular exercise, get enough sleep, try relaxation techniques such as massage and meditation, laugh, nurture one or two good friendships, and help others to give your mind a temporary break from your own problems.
- Eat fewer refined carbohydrate foods such as plain pasta, white bread, cakes, biscuits, pies and anything high in sugar.
- Choose complex carbohydrates.Choose wholemeal, whole grain bread and whole grain breakfast cereals such as muesli or oats, and whole grain pasta. Eat plenty of vegetables and fruit.
- Drink water. Make it tap, still or sparkling water rather than juice or fizzy drinks.
- Limit alcohol.
- Swap saturated fat for unsaturated fat. Eat a small handful of raw nuts or hummus on whole grain crackers rather than cheese on high-fat crackers. Swap from butter to oil. Use avocado as a spread instead of butter.
- Eat some low-fat dairy foods each day. There is a possible link between calcium intake and visceral fat. In one study the more calcium women had in their diet, the less visceral fat they gained over a year. More studies are needed to determine the ideal amount of calcium.
- If you need to lose weight, reduce your serve size. Serve meals on a smaller plate and always sit down to eat – no snacking on the run. Drink a glass of water with your meal to slow down eating.
- Subcutaneous fat can be pinched. It sits just under the skin.
- Visceral fat can’t be pinched. It sits inside the body, around the abdominal organs.